spamboli I have never seen copper sewer pipes at all - as far as I know we moved from ceramics (thick glazed earthenware) straight to PVC in this country.
@@JasperJanssen Wow I just looked it up and I had no idea copper pipes so big around had been commonly used so recently! I thought for sure that was cast iron we were looking at! Incredible that copper was ever so affordable...
Love the new House Debugging series :) In truth, your investigative logic for solving these everyday issues is great to learn from - thanks for sharing
Matthias, you didn't mention how much roof venting you had. Many years ago I had to go up into my house's attic (house build 1990) and found many of the rafters covered in a fine hoarfrost. My neighbour (a roofer) told me that all ceiling leak a little air and humidity, and if the roof space didn't have enough ventilation the humidity hung around and collected on the trusses and rafters. On a warm day the frost melted and collected in the insulation, much like you were seeing around some of the vertical posts. After our new roof and the very large vents put in I never saw the hoarfrost again. I hadn't made any changes to any of the vapour barriers , so this was all roof venting.
Here in cold Finland vapour barrier is mandatory. When I was renovating my house, I noticed tiny holes my vapour barrier in the sealing and there was mold above each one.
Same in Denmark. Building code even require new houses to be pressure tested, to make sure the vapor barrier are 100% tight. They even tape up the keyholes in the front and back door, as air leaving the keyholes are enough for the house to fail the pressure test...
Vapor barriers are also required for new construction and renovation in my very cold part of the United States, and to my knowledge they are required in Canada as well. I think what Matthias was getting at was that vapor barriers weren't invented when his home was built in the 1960s.
Precisely what I'd thought right away as well, haha! My imagination half-wanted him to somehow grab a slimy ghost hiding in the insulation, and casually get rid of it before continuing as if nothing happened.
Had the exact same thing happen to my in my basement last winter. Warm air was getting behind the insulation, creating a layer of frost on the inside of the outside wall on the cold days. Then during the warm days, it would melt, run down the inside of the wall and form puddles on the floor. Had to rip out all the fibreglass insulation and replaced it with foam all around. Very pricey to do, but worth every penny as the basement is considerably warmer now. Glad you were able to figure it out. Love these types of videos!
Really is, I have plastic shed and before insulating/regulating temperature/ dehumidifying the damn thing I thought the plastic rivets in the roof were not water tight and rain was getting through.
@@TheLunnyBear Exactly. So many times I see water in the attic at a customer's home and they are convinced the roof is leaking when in fact they have zero insulation and it's simply condensing on the rafters.
So much so that you could use a dehumidifier as a "water from thin air" source of water for drinking and irrigation? Hehe, I hear rumbling in the distance - almost like thunder, or a large foot banging around...
...and how much water you can lose to just evaporation. I have baseboard heat and have to run a console humidifier in the winter to keep a comfortable humidity level. It's an old school fan and fiber belt design that requires manually refilling from a bucket. Roughly 3-5 gallons a day most days just disappears XD
I wish more people understood how water and then mold can develop in attics. Every one thinks it has to be a leak but improper venting and poor sealing can do a ton of damage.
Ive investigated this exact same problem in my 50's house. Essentially what it comes down to is insufficient sealing and not enough ventilation. My house was reasonably well sealed, and had lots of insulation, so I increased the ventilation and my problems have been solved. I have a story and a bit so the ventilation between attic spaces was zero.
I have been in the residential insulation business since 1994, every wire or pipe that runs up through a wall up into the attic is going to leak air. They all should be air sealed with foam or caulk. Seeing as you have so much insulation in the attic, this will be near impossible. You can however reduce the amount of updraft by sealing all the holes in your basement ceiling. With the holes in the top plate of the wall and any holes in the bottom plate, they just act like little chimneys and suck the heat right out. Same goes for any ceiling fixtures and they should be IC rated fixtures. (Insulation Contact)
The stain in the insulation is from the air getting filtered by insulation or getting wet, moist air coming up from the house condensating on the wood and when the ice thaws it wets the wood...i had the same problem between my rim joists, they were insulation but no vapor barrier, the insulation was stuck to the OSB and the OSB was getting soft in some areas...some people are just clueless about that. Nice video, i hope it helps some people out there!
Also check the ducting on any bathroom, kitchen, or other vent fans. In my house of similar vintage in a similar climate, the vents had been run into the attic, but not ducted on out through the roof. The warm moist air was vented directly into the attic space. In addition to the problems you noticed, I discovered that moisture had migrated through the sheathing and then condensed on the underside of the shingles. Both the shingles and the sheathing needed to be replaced far sooner than expected. Your water staining looks very similar to what I discovered, so please do check to make sure the underside of your shingles is staying dry.
The fact that condensate is forming on the wood shows a lack of insulation and or ventilation. Wrap the pipe with insulation as much as you can. Newer plumbing vents are ABS or PVC and tend to not condensate compared to the copper. Add attic insulation (looks low) and venting (soffit vents / baffles especially). If this condition continues you can quickly develop mold.
You think that attic insulation looked LOW? He had at least 3 different fills in there and I'd guess it's around 24" deep. I've been in more attics than most people have been in homes, and an attic with as much insulation as that one is rare, and a pain in the ass.
@@billybobjoe198 I trust that you've been in a plethora of attics. Congratulations you win! Please re read all of my post and respectfully, do not reply.
@@stevegraves2890 "Add attic insulation (looks low)". There's no two ways about this. You said his insulation is low. I disagreed. You don't have some sort of stipulation or context elsewhere in your comment to frame that differently. It's plain. It's blunt. It's straight forward. I don't play with kid gloves. You don't have the intelligence to play the smug arrogant card. When a 2 second fact check blows you out of the water, you're out classed by 75% of the population. It's okay to have low cognitive abilities, someone has to, it's all relative. Make it easier on yourself by understanding and acting accordingly.
2 - 3 coats of oil based semi-gloss or gloss paint was sometimes said to be a reasonable substitute for a plastic vapour barrier. I'm curious if this is true? Sealing floor/wall joints, around windows, doors, electrical boxes etc. is another story and as your investigation shows, the bigger problem. That sealing is not done well (if at all) at all, in my 1999 built home.
True, oil based paint will generally have a much lower vapor permeability than a typical acrylic equivalent. I believe now there are acrylic paints readily available that are designed as a low permeability vapor retarder, though.
Though it's not a requirement for passive plumbing vent pipes, where I am in the US, code requires insulation on active bathroom vent fan ducts that penetrate unconditioned space (usually through an attic) for the same reason that they're full of very warm, moist air from the bathroom. In cold conditions, vapor in the attic space will condense on the uninsulated duct and leak below, just as you see. You can buy duct insulation that would wrap around this vent pipe and likely help your problem in addition to the spray foam you used.
Spot on, and yet nearly every bathroom exhaust fan I see is ducted out in the garbage foil flex that comes with the vent kits, if it's ducted out at all...
If you build some kind of contraption around the exposed vent pipe to collect the condensation and channel it to a drain you would basically have a free attic dehumidifier and might see less condensation on the bracing because of it.
@@maxdecphoenix Too easy. Also it won't solve the condensation on the roof truss members. Also it won't provide an entertaining Matthias-contraption video.
@@kenklose They're different Issues.. it doesn't have to solve the condensation on the trusses. What an idiotic response. I suppose if someone mentioned how to resolve the condensation on the trusses, you'd argue 'that doesn't solve the condensation on the pipe!'. Just dumb. Guess what, there's different solutions, to different problems. You insulate the pipe to stop moisture condensing under the fiberglass, and you increase the air movement in the coldzone above the fiberglass to carry the moisture out.
More likely the PVC would be colder in the attic than copper, because copper is a better thermal conductor and it would conduct the heat from the house up to the attic better than PVC, so the PVC would be closer to the ambient attic temperature than copper.
PVC or copper is not the problem here. The pipe is so thin, it does not begin to compare with 10 cm / 4 inches of insulation. That means that both pipes will be a cold bridge. Any warm air hitting a cold bridge, will be cooled down untill it hits dew point and releases its moisture onto the outside of the pipe. A solution to the dripping water on the pipe would be to insulate that pipe from the point it goes into the attic, up to the point it gets out of the building.
Good diagnosis. This is the very same reason why 1) attic ventilation is important in the winter as well as the summer, and 2) Bathroom exhaust fans dumping into the attic can cause significant problems, especially in the winter, when lots of hot humid air hits a freezing cold closed area. We always insulated ductwork / exhaust ventilation and plastic plumbing vent with lots of spray foam at all ceiling and wall plate penetrations. Sealing the air leaks also serves double as a fire stop. One thing I've always wondered, excluding old copper drain systems, everywhere I've worked in the states has almost universally used PVC pipe for DVW plumbing, with ABS pipe being the rare exception (like my house from 1977 / 1978 used). In Canada, ABS appears to be the de facto drain pipe. Coincidence, or for reason?
@@16ats All of the DWV piping original to my 1960s home is 3 inch copper, too. It's super thin, though, so it doesn't weigh much, so unfortunately what I've replaced due to leaks isn't quite the fortune in scrap I'd hope it'd be.
@@SuperSpecs Well in europe, at least here in estonia, where in the 60's was soviet era, all toilet pipes and such, were made of cast iron :D At least in the apartment buildings. Back then iron was dirt cheap. Houses were built mostly dry toilets anyway. Back then, even if you had money, stuff weren't available to buy. #sovietlife :D
Yup, this really does demonstrate the importance of a vapour barrier. Unfortunately retrofitting one is not cheap or easy (maybe even not practical to do)
I hear ya, my last house D'bugging was to change a bunch of electrical outlets in the house to 3 prong. My house built in the 50's or 60's era was not thought out well electrically. Too many rooms on the same breaker, and too many 2 prong plugs. Oh yeah just had my roof re-done. In BC Canada I paid about $25,000.
Hi Matthias. I you have access to a thermal camera, it lets you see exactly where damp is coming from, and it easily sees where there's missing insulation, and hot or cold leaks. I'm using my Cat s60 thermal smartphone at work to see the underfloor heating pipes.
Could also be snow blowing in from the roof vents, but I couldn't see any in the video. You could insulate the copper vent stack with pipe insulation (used for bathroom fan exhaust pipes). This would protect the exposed section of stack vent within the attic. You could also remove that section of copper pipe and replace with ABS, which is less susceptible to thermal transfer. If you were really ambitious you could replace the whole stack, but that may be difficult. The scrap copper would pay for the swap to ABS.
I've heard of hot humid air from the bathroom exhaust flowing back into the attic through soffit vents, if the bathroom air exhausts to the soffit or the wall below it.
@@peter_smyth It absolutely can and will, and yet I still see 'reputable professionals' do this frequently because they don't want to be inconvenienced to make a roof penetration.
I’m gonna need a build video for the paper towel holder on a stick. Knowing Matthias, there is no way it’s as simple as tying a paper towel on an extra piece of wood.
You are on the right track Matt. Now go through the entire attic at every place a wire or pipe comes from the house into the attic, hit the hole with spray foam. Home will feel the way it should and no more mystery drips.
A warm spell after a particularly cold winter in Wpg, a few years ago yielded _much_ water leaking from the attic into my house. A lot of frost had built up in the attic and then melted. I have sealed off the internal access and installed a door in the gable outside. I removed the exhaust fans from the ceilings of both bathrooms and installed an HRV unit in the basement which is 'plumbed' to pull air from vents I installed in the walls of the bathrooms (near the ceiling). I also replaced my mid-efficient furnace and sealed off where the chimney used to pass through the ceiling. House is a 70's build. Vapor barrier on ceilings, but they didn't put it over the walls (between wall headers and ceiling rafters), so still a bit of leaking. It's much better - and I'm hoping that by reducing the number of holes, and adding the HRV I have solved or at least reduced to acceptable limits the problem.
I just think it's his favourite pen. And I can understand. Maybe there's some nostalgic feeling involved, because that was the classic Pelikan fountain pen (with its little ink window) most children had as their first one when they learned writing at their first school. That model was extremely common at least in all the 80s, I guess. And I do remember that the standard model had a rather broad and nicely gliding tip with perfect ink flow that made writing ready and comfortable. Not comparable to any roller pen. I used that fountain pen also for years and still have the most detailed memories about how the grip felt and its writing feedback on different kinds of paper. Strange how things like that can burn themselves into ones memories. What I wanted to say: Maybe he also has been appreciating the fountain pen's qualities for decades and mixed with some memories from childhood in Germany, he keeps on to it. 😊 Why not when it's still working perfectly.
It also may be stagnant air in the attic. if there is now air flow though the attic to take out the warm moist air that ultimately make it up through the insulation it will hit the cold roof sheeting and turn to condensation or frost and melt when it gets warm. new houses now a days have vented sofits and a vented ridge cap to pull the warm air that makes it into the attic out through the ridge pulling cold dry air up through the vented sofits. Just an Idea you may have all that and it was not on the vid
What about temperature differences in the pipe vs its surroundings as it makes the transition between an interior wall (warm) and the attic (cold)? Seems like you'd have cold pipe for a bit inside your walls regardless of an air barrier
Spot on. It's a classic "cold bridge". The pipe needs to be insulated. If it was insulated untill its outlet, it would keep (more or less) its interior warmth and have a dew point at the place where it sticks outside of the house. Now that dew point is below the insulated ceiling, and it will continue dripping water.
Had serius problems in a 5000 sqm factory about 5 years ago. Moist air went up to the attic and condensed on the metal construction and sheet metal roof. In the production it created a lot of steam in the process, so it was moist all the time. With warm weather all this came back down. Got rid of it by adding big ventilator to 1 side of the building and an opening to the other end , so the air passed the attic moving moist air out.
Seems like you'd want to wrap that vent pipe completely in insulation. You could still have a situation where the attic has some moisture in the air and the vent pipe would be below the dew point...
I think it is condensation from the pipe, when cold dry air meets warm moist air, the condensation settles to a zero point. Just as you take a glass bottle out of the fridge on a hot day. By isolating the pipe all the way up, the problem will disappear.
Copper is great but it's also a very good thermal conductor so I'd cut it off between the ceiling joists and couple it to PVC to go out the roof. Pretty low cost fix overall. I guess you'd have to wait for some warmer weather and be prepared to install new vent flashing if needed. If you have any bath vents, be sure they don't just dump into the attic like mine did.
Those attic-facing fixtures should have moisture barrier and sealant behind them. Obviously they were installed without a permit; or pre-date the vapor barrier being added to code. Highly recommend adding a polypropylene vapor box on top of those lights and any other penetration into the attic space to eliminate such problems.
Enjoyed this - insulating seems so simple - but it is not simple at all - and it is almost never debugged. I think a lot of insulation is ineffective as a result.
Every time you flush air will be drawn into the system. What if you insulate all of the copper vent that passes through the attic. What type of ventilation do you have in the attic space. Is there a ridge vent or just the gable vents. Is there a fan? Is there a bathrood vent fan that exhausts through the attic? Many of those are supplied with cheap plastic hose which will deteriorate over time. If it did or the duct became disconnected moisture would be pumped into the attic space.
Looks like the vent comes up thru the partition wall which all your roof rafters are point loaded down to....that wall is probably not insulated, and the lumber has a relatively low r value carrying heat up into the space and into those rafter braces....meeting the cold air and condensing on each of those 2x4s. Probably before the blown in insulation at those points.
I wonder if your use of the basement shop space (as opposed to rarely-visited/uninhabited storage before?) could have contributed more warm/moist air up that pipe chase? Would just be one human's worth of moisture -- wonder how much vapor a person emits per day. Could sealing it off from the bottom (where you stuck a stick/towel up it) prevent enough moisture from rising up there in the first place? Of course, then you know even less what's going on up in there, whereas if you leave it open and it drips on you again that will be a good sign you need to re-investigate. Looking forward to the follow-up!
Makes me glad that my 100 yr old house has the sewer pipe leave through the wall with the length of the vent pipe running up on the exterior. Maybe only works here in Vancouver though with our mild winters to prevent freezing.
That long pipe up to the roof (vent) wouldn't have cold air falling down it if there was a sewer trap. This is where the pipe goes down and then up to trap a portion of water that prevents drafts, but still allows venting of sewer gasses. Similarly, a lot of buildings have floor drains that have these traps, but if the drains aren't used to drain water very often, the trap water dries up, which allows a draft from the sewer which you can easily smell. If this long section of pipe that gets cold has a trap, but you don't use the drains or flush the toilets on that stack very often, the trap could be drying up allowing a cold air draft down that pipe, which would enhance condensation build up. Just a guess
Wrap fiberglass batting insulation around the pipe and secure it with tuck tape. The problem will continue to happen because when the pipe is in use, cold air is drawn in and cools the pipe, any moisture around it will condense on the pipe. When the pipe warms back up from the heat in your home it will melt and run down the pipe. You were correct in foaming but to fully remedy this the pipe needs to be insulated.
I had a similar problem with dripping water from the vent pipe. I found a very small crack on the joint, where the horizontal vent pipe was connected to the main one. The water was sipping from inside of the vent pipe and goes down. I would suggest you to check that as well.
Wow, crazy... I'm surprised this is the first I've heard of this: I live in a newer house now, but lived in an older one with metal dwv for several years... Lot of people mentioning vapor barrier, which I guess can be good in the attic behind drywall, but I've found in a basement storage area, vapor barrier against the insulation was just causing condensation and mold in the insulation: presumably wasn't sealed off enough to prevent all humid air from entering, so instead just provided a place to condense and an impediment to removing moisture...
There's always a right and a wrong side of the insulation to have the vapor barrier on, but in a lot of instances what's right in heating season will be wrong in cooling season
Installing or having to get back into that white fluffy stuff is like a vacation compared to regular fiberglass or cellulose. That's my preferred attic insulation as long as I don't have to pay for it
With a little commitment, you can do at least as well as the average professional would do. You won't do it as quickly, sure, but you'll save a ton of money and know exactly who to blame if it's not perfect. The consequence is you'll start finding flaws in nearly any professionally done repairs which were either missed out of negligence, or just skipped because it's something the average homeowner will never notice anyways.
@@matthiasrandomstuff2221 My apologies I thought you said it didn't have one. Still an essential part of the overall construction of the house that tends to not be done right, if its installed at all.
Architect here - how many roof vents do you have? A common problem if you don't have enough roof ventilation is moisture accumulation which would leave the marks your seeing - warm humid air rises through every opening in the ceiling, it condenses, lands on the insulation, then gets absorbed when it warms up and the wood toughing the insulation absorbs it. From the pattern it looks like the water marks line up with your insulation suggesting it's a current issue. In terms of ventilation, Not only do you want flapper vents (at least 4 or more depending on the size of your roof) but you also want to double check that there are baffles adjacent to your soffit vents. If the blown insulation guys didn't install baffles, the humid air that gets into the attic will have nowhere to go - the soffits pull in fresh air and wind blowing outside sucks it up through the roof vents. Blown insulation is notorious for blocking them. You're correct about vapour barriers but every single pot light will let humid air into the attic - especially that box you revealed which should really have a VB shroud around it. You can VB the ceiling with any coat of paint that has a rating of
I believe the cause of this is the cold pipe itself, not the air escaping from the room - without vapour barrier the air is finding all, even microscopic gaps in the constructions. Another problem is the insulation - it is said the natural fibre insulation, like the cellulose wool will absorb the moisture, as opposed to glass or mineral wool, what will be wet in the touch, as in your case. I would be tempted to try to insulate the pipe itself in the attic.
Moistening of the insulation over the course of the winter is a total normal ocurrance. It only becomes a problem when the evaporation rate in the summer is less than the condasation rate in the winter. Then water would build up. But if that's not the case, you are good to go.
It can show you the cold spots in a room, which might indicate a cold bridge, a low level of insulation or air leakage. They might also act as condensation points. If that condensation cannot get away through ventilation you'll get mold.
What do you think about more roof vents to let out moisture before it condenses ? Roofing pros seem to suggest much more venting now than they did decades ago too.
Those are a good idea, but wouldn't help with this particular case. The condensation happened in the insulation, before it really got to the attic air.
Berra, there is no renovation solution at this point, only mitigation; but the mitigation can throttle down (maybe never off) most of the moist effect.
Is that a metal soil stack? This seems like it's designed to eventually fail (via condensation and chemical corrosion). I'd swap it out for lovely, non-conductive PVC.
@@matthiasrandomstuff2221 The vertical section, yes. The horizontal sections, far sooner, particularly where sewer gas accumulates at the top of the pipe cross section. This is far more prevalent on legs where there isn't a good draft and the gas stagnates. The pipe will deteriorate at the top and effectively turn into a gutter. You'll know it when you start smelling sewer gas, or when the pipe fills up from the inrush of a toilet flush and leaks over.
You want an air barrier more than a vapor barrier inside your house. Drywall is a good air barrier. It is not a huge job to close up the gaps, but it will be a dirty day. Building Science Corp is a great resource if you want to go down the rabbit hole of vapor diffusion, air sealing, case studies, etc
Make sure to have negative pressure ventilation. Especially in winter. That is, lower pressure inside than out. Otherwise you will get problems with condensation. In the old times chimneys were warm and provided this negative pressure from the draft. Today with less burning, extra fans, always on, for the kitchen and the bathrooms might be needed.
@@mckenziekeith7434 Yes, indeed it is a great idea. It is how houses was built for centuries, if not millennia. With a fire inside and some form of chimney, negative pressure inside is what you get. With modern heating that doesn't consume air, you get positive pressure, condensation, mold and rot. You need just enough forced negative pressure to ensure it never becomes positive.
@@adoby83 I guess I was wrong. But I still think the best idea is to have a well sealed house so that warm air can't easily escape and cold air can't easily infiltrate. But slight negative pressure would seem to be better than positive in cold climates. I don't necessarily hold up old houses as the best examples of thermal design. Often they were designed with the idea of running huge roaring fires in huge fireplaces to keep warm. I live in a mild climate so don't have to worry about these things as much.
You should stuff some insulation in the gap in the basement where the vent pipe goes up. The warm air in the basement is using that space like a chimney.
Hot air contains more water than cold. Cold air is heavier than hot. Hot air rises. Hot air rises from bathroom, kitchen, breath, shower etc. The warm air seeps up in the insulation, but when the temperature drops, the air cannot hold as much moisture. Then condensation occurs. The type of insulation you have cannot store the moisture. Cellulose or others Wood-based insulation types can absorb moisture Your problem is because you do not have a vapor barrier.
Interesting problem, I'm not used to seeing copper stacks, so maybe that's why I've never heard about it. Old homes I work in tend to be from the late 1800's to the early 1950's, and they have cast iron and lead drain lines. Newer homes I work on tend to be 1970's+ and they all have pvc or abs drain lines. The few times I've worked on 60's homes they've all been a nightmare because of aluminum wiring and galvanized water supplies. That stack is cut pretty tight, It's not uncommon to see a big chunk cut out of a 2x6 wall for the stack to poke through. Looks like a well built home. I don't know how much you care about code, but here at least, an inspector would cry that you didn't use fire block foam. The difference? Who knows! but it's slightly orange. Not that any inspector will know when it was done, and it's an obvious improvement over what was already there.
Today on This Old House: Some maple nerd sprays spunk all up in his attic, we'll have Richard "Full City Water Pressure" Trethaway help him out when his flight lands.
Hi hallo, Sorry wenn ich mich da nun dazu melde aber......... But copper is a very good heat conductor. The problem with the moisture comes from the fact that cold air "flows" in the pipe and around the copper pipe the heated air condenses on the cold pipe and drips down at the bottom. Cold air still flows down from the top of the duct At times so much that puddles of water can form on the bottom, there are two ways to solve the problem and keep the moisture in areas, one is the shaft where the pipe goes up completely to the outside of the roof against a thick-walled plastic drain pipe swap, or to wrap the copper pipe with a felt insulation tape, but I recommend swapping the copper pipe for a HT pipe and completely insulating the shaft with insulating wool........ grüsse aus Berlin
No, that white fluffy stuff is a modern fiberglass product, and the yellow fluff is almost certainly just an older fiberglass based blown in insulation. The more common type to likely contain asbestos was vermiculite, which was a mineral based loose fill resembling a very light weight kitty litter.
"House debugging?" - "It's never Lupus."
This is why we insulate vent pipes. That's how you actually fix this.
a plastic pipe would also work better - it would hold & transfer less heat than the copper
@@spamboli insulate plasticpipe too
Joshua has the correct theory.
spamboli I have never seen copper sewer pipes at all - as far as I know we moved from ceramics (thick glazed earthenware) straight to PVC in this country.
@@JasperJanssen Wow I just looked it up and I had no idea copper pipes so big around had been commonly used so recently! I thought for sure that was cast iron we were looking at! Incredible that copper was ever so affordable...
At 3:08
"Rachel, if something bad happens, pull me out with the rope!!"
Willow B yeah I think that was the extension cord😂
@@brandonb9452 i know :)
Brandy Ellis it’s a joke
Techmatt167 um yeah thanks for the clarification..
@@brandonb9452 They were joking!
when he went up in the attic he kinda looked like mac gyver going on an adventure... "rachel i'm back in a couple of days" ;D
Love the new House Debugging series :)
In truth, your investigative logic for solving these everyday issues is great to learn from - thanks for sharing
"House debugging" :D
Matthias, you didn't mention how much roof venting you had. Many years ago I had to go up into my house's attic (house build 1990) and found many of the rafters covered in a fine hoarfrost. My neighbour (a roofer) told me that all ceiling leak a little air and humidity, and if the roof space didn't have enough ventilation the humidity hung around and collected on the trusses and rafters. On a warm day the frost melted and collected in the insulation, much like you were seeing around some of the vertical posts. After our new roof and the very large vents put in I never saw the hoarfrost again. I hadn't made any changes to any of the vapour barriers , so this was all roof venting.
good point
Here in cold Finland vapour barrier is mandatory. When I was renovating my house, I noticed tiny holes my vapour barrier in the sealing and there was mold above each one.
Same in Denmark. Building code even require new houses to be pressure tested, to make sure the vapor barrier are 100% tight. They even tape up the keyholes in the front and back door, as air leaving the keyholes are enough for the house to fail the pressure test...
Vapor barriers are also required for new construction and renovation in my very cold part of the United States, and to my knowledge they are required in Canada as well. I think what Matthias was getting at was that vapor barriers weren't invented when his home was built in the 1960s.
He should for sure remove the isolation and add the vapour barrier. A moist pullover does not keep warm🙈.
3:06 Look like Matthias went ghostbusting ;)
Exactly what I thought too :)
Precisely what I'd thought right away as well, haha! My imagination half-wanted him to somehow grab a slimy ghost hiding in the insulation, and casually get rid of it before continuing as if nothing happened.
Had the exact same thing happen to my in my basement last winter. Warm air was getting behind the insulation, creating a layer of frost on the inside of the outside wall on the cold days. Then during the warm days, it would melt, run down the inside of the wall and form puddles on the floor. Had to rip out all the fibreglass insulation and replaced it with foam all around. Very pricey to do, but worth every penny as the basement is considerably warmer now. Glad you were able to figure it out. Love these types of videos!
It's actually amazing how much water you can get just from condensation.
Really is, I have plastic shed and before insulating/regulating temperature/ dehumidifying the damn thing I thought the plastic rivets in the roof were not water tight and rain was getting through.
@@TheLunnyBear Exactly. So many times I see water in the attic at a customer's home and they are convinced the roof is leaking when in fact they have zero insulation and it's simply condensing on the rafters.
So much so that you could use a dehumidifier as a "water from thin air" source of water for drinking and irrigation? Hehe, I hear rumbling in the distance - almost like thunder, or a large foot banging around...
...and how much water you can lose to just evaporation. I have baseboard heat and have to run a console humidifier in the winter to keep a comfortable humidity level. It's an old school fan and fiber belt design that requires manually refilling from a bucket. Roughly 3-5 gallons a day most days just disappears XD
I wish more people understood how water and then mold can develop in attics. Every one thinks it has to be a leak but improper venting and poor sealing can do a ton of damage.
Diffusion and convection.Pretty simple actually.
Ive investigated this exact same problem in my 50's house. Essentially what it comes down to is insufficient sealing and not enough ventilation. My house was reasonably well sealed, and had lots of insulation, so I increased the ventilation and my problems have been solved. I have a story and a bit so the ventilation between attic spaces was zero.
I have been in the residential insulation business since 1994, every wire or pipe that runs up through a wall up into the attic is going to leak air. They all should be air sealed with foam or caulk. Seeing as you have so much insulation in the attic, this will be near impossible. You can however reduce the amount of updraft by sealing all the holes in your basement ceiling. With the holes in the top plate of the wall and any holes in the bottom plate, they just act like little chimneys and suck the heat right out. Same goes for any ceiling fixtures and they should be IC rated fixtures. (Insulation Contact)
I owned an older house (1910's) and the chimney used to do this all the time - it was a nightmare to get the insulation/air circulation balance right.
The stain in the insulation is from the air getting filtered by insulation or getting wet, moist air coming up from the house condensating on the wood and when the ice thaws it wets the wood...i had the same problem between my rim joists, they were insulation but no vapor barrier, the insulation was stuck to the OSB and the OSB was getting soft in some areas...some people are just clueless about that. Nice video, i hope it helps some people out there!
Some people? Most people, to include most builders!
At first glance I thought you had snow in your attic :)
Me too, which made the questioning of the moisture just a bit funnier
Also check the ducting on any bathroom, kitchen, or other vent fans. In my house of similar vintage in a similar climate, the vents had been run into the attic, but not ducted on out through the roof. The warm moist air was vented directly into the attic space. In addition to the problems you noticed, I discovered that moisture had migrated through the sheathing and then condensed on the underside of the shingles. Both the shingles and the sheathing needed to be replaced far sooner than expected.
Your water staining looks very similar to what I discovered, so please do check to make sure the underside of your shingles is staying dry.
The fact that condensate is forming on the wood shows a lack of insulation and or ventilation.
Wrap the pipe with insulation as much as you can. Newer plumbing vents are ABS or PVC and tend to not condensate compared to the copper. Add attic insulation (looks low) and venting (soffit vents / baffles especially).
If this condition continues you can quickly develop mold.
You think that attic insulation looked LOW? He had at least 3 different fills in there and I'd guess it's around 24" deep.
I've been in more attics than most people have been in homes, and an attic with as much insulation as that one is rare, and a pain in the ass.
@@billybobjoe198 I trust that you've been in a plethora of attics. Congratulations you win! Please re read all of my post and respectfully, do not reply.
@@stevegraves2890 "Add attic insulation (looks low)". There's no two ways about this.
You said his insulation is low. I disagreed. You don't have some sort of stipulation or context elsewhere in your comment to frame that differently. It's plain. It's blunt. It's straight forward. I don't play with kid gloves. You don't have the intelligence to play the smug arrogant card. When a 2 second fact check blows you out of the water, you're out classed by 75% of the population. It's okay to have low cognitive abilities, someone has to, it's all relative. Make it easier on yourself by understanding and acting accordingly.
@@billybobjoe198 Not when it comes time to pay the heating bill.
That vent pipe isn't copper, it's cast iron.
2 - 3 coats of oil based semi-gloss or gloss paint was sometimes said to be a reasonable substitute for a plastic vapour barrier. I'm curious if this is true? Sealing floor/wall joints, around windows, doors, electrical boxes etc. is another story and as your investigation shows, the bigger problem. That sealing is not done well (if at all) at all, in my 1999 built home.
True, oil based paint will generally have a much lower vapor permeability than a typical acrylic equivalent. I believe now there are acrylic paints readily available that are designed as a low permeability vapor retarder, though.
Though it's not a requirement for passive plumbing vent pipes, where I am in the US, code requires insulation on active bathroom vent fan ducts that penetrate unconditioned space (usually through an attic) for the same reason that they're full of very warm, moist air from the bathroom. In cold conditions, vapor in the attic space will condense on the uninsulated duct and leak below, just as you see. You can buy duct insulation that would wrap around this vent pipe and likely help your problem in addition to the spray foam you used.
Spot on, and yet nearly every bathroom exhaust fan I see is ducted out in the garbage foil flex that comes with the vent kits, if it's ducted out at all...
Matthias Wandel for president! You're awesome. The world needs more people like you!
If you build some kind of contraption around the exposed vent pipe to collect the condensation and channel it to a drain you would basically have a free attic dehumidifier and might see less condensation on the bracing because of it.
Just insulate the vent pipe and it won't condense.
@@maxdecphoenix Too easy. Also it won't solve the condensation on the roof truss members. Also it won't provide an entertaining Matthias-contraption video.
@@kenklose They're different Issues.. it doesn't have to solve the condensation on the trusses. What an idiotic response. I suppose if someone mentioned how to resolve the condensation on the trusses, you'd argue 'that doesn't solve the condensation on the pipe!'. Just dumb. Guess what, there's different solutions, to different problems. You insulate the pipe to stop moisture condensing under the fiberglass, and you increase the air movement in the coldzone above the fiberglass to carry the moisture out.
@@maxdecphoenix I'm talking about an entertaining Matthias contraption video, that's all, no reason to break out insults.
Nice job Matthias, hope you solved this issue 👍🏻
I bet that copper vent pipe gets pretty cold. With PVC vent pipes used in newer houses condensation would be less of a problem.
More likely the PVC would be colder in the attic than copper, because copper is a better thermal conductor and it would conduct the heat from the house up to the attic better than PVC, so the PVC would be closer to the ambient attic temperature than copper.
PVC or copper is not the problem here. The pipe is so thin, it does not begin to compare with 10 cm / 4 inches of insulation. That means that both pipes will be a cold bridge. Any warm air hitting a cold bridge, will be cooled down untill it hits dew point and releases its moisture onto the outside of the pipe. A solution to the dripping water on the pipe would be to insulate that pipe from the point it goes into the attic, up to the point it gets out of the building.
@@peterslegers6121 No, insulating the pipe will not help.
@@XJWill1 why not, what´s the mechanic behind your statement?
You should get an IR camera - then you could find warm air leaks easily.
Might want to check and make sure all venting is clear, without good airflow up there it could keep the humidity high, adding to the moisture problem.
Good diagnosis. This is the very same reason why 1) attic ventilation is important in the winter as well as the summer, and 2) Bathroom exhaust fans dumping into the attic can cause significant problems, especially in the winter, when lots of hot humid air hits a freezing cold closed area. We always insulated ductwork / exhaust ventilation and plastic plumbing vent with lots of spray foam at all ceiling and wall plate penetrations. Sealing the air leaks also serves double as a fire stop.
One thing I've always wondered, excluding old copper drain systems, everywhere I've worked in the states has almost universally used PVC pipe for DVW plumbing, with ABS pipe being the rare exception (like my house from 1977 / 1978 used). In Canada, ABS appears to be the de facto drain pipe. Coincidence, or for reason?
Your attic is a beautiful christmas wonderland
I love that stuff. It's not nearly as itchy or dusty to install or have to go back in for remodels. More expensive, though.
I love these problem investigation / solving videos.
A COPPER vent pipe?! Whoa! And yeah, virtually nobody who builds houses did real air sealing back then, or even now to a good degree.
I thought the same. That big copper pipe is worth some good money. Even in scrap
With less insulation, the air sealing was less critical.
@@16ats All of the DWV piping original to my 1960s home is 3 inch copper, too. It's super thin, though, so it doesn't weigh much, so unfortunately what I've replaced due to leaks isn't quite the fortune in scrap I'd hope it'd be.
@@SuperSpecs Well in europe, at least here in estonia, where in the 60's was soviet era, all toilet pipes and such, were made of cast iron :D At least in the apartment buildings. Back then iron was dirt cheap. Houses were built mostly dry toilets anyway. Back then, even if you had money, stuff weren't available to buy. #sovietlife :D
@@16ats yep and now we use pvc plastic 😊
Yup, this really does demonstrate the importance of a vapour barrier.
Unfortunately retrofitting one is not cheap or easy (maybe even not practical to do)
I hear ya, my last house D'bugging was to change a bunch of electrical outlets in the house to 3 prong. My house built in the 50's or 60's era was not thought out well electrically. Too many rooms on the same breaker, and too many 2 prong plugs. Oh yeah just had my roof re-done. In BC Canada I paid about $25,000.
Hi Matthias. I you have access to a thermal camera, it lets you see exactly where damp is coming from, and it easily sees where there's missing insulation, and hot or cold leaks. I'm using my Cat s60 thermal smartphone at work to see the underfloor heating pipes.
Could also be snow blowing in from the roof vents, but I couldn't see any in the video. You could insulate the copper vent stack with pipe insulation (used for bathroom fan exhaust pipes). This would protect the exposed section of stack vent within the attic. You could also remove that section of copper pipe and replace with ABS, which is less susceptible to thermal transfer. If you were really ambitious you could replace the whole stack, but that may be difficult. The scrap copper would pay for the swap to ABS.
Bathroom exhaust fan could also be source of attic humid air if the duct isn't air tight to exterior vent.
I've heard of hot humid air from the bathroom exhaust flowing back into the attic through soffit vents, if the bathroom air exhausts to the soffit or the wall below it.
@@peter_smyth It absolutely can and will, and yet I still see 'reputable professionals' do this frequently because they don't want to be inconvenienced to make a roof penetration.
I’m gonna need a build video for the paper towel holder on a stick. Knowing Matthias, there is no way it’s as simple as tying a paper towel on an extra piece of wood.
It all starts in sketchup, we print out a template, and glue it to a stick that's been run through the jointer and pantorouter XD
You are on the right track Matt. Now go through the entire attic at every place a wire or pipe comes from the house into the attic, hit the hole with spray foam. Home will feel the way it should and no more mystery drips.
A warm spell after a particularly cold winter in Wpg, a few years ago yielded _much_ water leaking from the attic into my house. A lot of frost had built up in the attic and then melted. I have sealed off the internal access and installed a door in the gable outside. I removed the exhaust fans from the ceilings of both bathrooms and installed an HRV unit in the basement which is 'plumbed' to pull air from vents I installed in the walls of the bathrooms (near the ceiling). I also replaced my mid-efficient furnace and sealed off where the chimney used to pass through the ceiling. House is a 70's build. Vapor barrier on ceilings, but they didn't put it over the walls (between wall headers and ceiling rafters), so still a bit of leaking. It's much better - and I'm hoping that by reducing the number of holes, and adding the HRV I have solved or at least reduced to acceptable limits the problem.
Mathias showing off his fountain pen yet again
I just think it's his favourite pen. And I can understand. Maybe there's some nostalgic feeling involved, because that was the classic Pelikan fountain pen (with its little ink window) most children had as their first one when they learned writing at their first school. That model was extremely common at least in all the 80s, I guess. And I do remember that the standard model had a rather broad and nicely gliding tip with perfect ink flow that made writing ready and comfortable. Not comparable to any roller pen. I used that fountain pen also for years and still have the most detailed memories about how the grip felt and its writing feedback on different kinds of paper. Strange how things like that can burn themselves into ones memories.
What I wanted to say: Maybe he also has been appreciating the fountain pen's qualities for decades and mixed with some memories from childhood in Germany, he keeps on to it. 😊 Why not when it's still working perfectly.
It also may be stagnant air in the attic. if there is now air flow though the attic to take out the warm moist air that ultimately make it up through the insulation it will hit the cold roof sheeting and turn to condensation or frost and melt when it gets warm. new houses now a days have vented sofits and a vented ridge cap to pull the warm air that makes it into the attic out through the ridge pulling cold dry air up through the vented sofits. Just an Idea you may have all that and it was not on the vid
What about temperature differences in the pipe vs its surroundings as it makes the transition between an interior wall (warm) and the attic (cold)? Seems like you'd have cold pipe for a bit inside your walls regardless of an air barrier
Spot on. It's a classic "cold bridge". The pipe needs to be insulated. If it was insulated untill its outlet, it would keep (more or less) its interior warmth and have a dew point at the place where it sticks outside of the house. Now that dew point is below the insulated ceiling, and it will continue dripping water.
Had serius problems in a 5000 sqm factory about 5 years ago. Moist air went up to the attic and condensed on the metal construction and sheet metal roof. In the production it created a lot of steam in the process, so it was moist all the time. With warm weather all this came back down. Got rid of it by adding big ventilator to 1 side of the building and an opening to the other end , so the air passed the attic moving moist air out.
"house debugging" LOL! Make sure you're using the correct syntax!
Seems like you'd want to wrap that vent pipe completely in insulation. You could still have a situation where the attic has some moisture in the air and the vent pipe would be below the dew point...
Indeed. Summer, humid day, draft from underground sewer up vent and out roof and you've got the potential for a cold drink on a hot day condensation.
I think it is condensation from the pipe, when cold dry air meets warm moist air, the condensation settles to a zero point. Just as you take a glass bottle out of the fridge on a hot day. By isolating the pipe all the way up, the problem will disappear.
Indeed. Cold bridge.
A thermal camera would probably be useful for finding the major air leaks. Might be worth renting one.
He has one.
Copper is great but it's also a very good thermal conductor so I'd cut it off between the ceiling joists and couple it to PVC to go out the roof. Pretty low cost fix overall. I guess you'd have to wait for some warmer weather and be prepared to install new vent flashing if needed. If you have any bath vents, be sure they don't just dump into the attic like mine did.
Those attic-facing fixtures should have moisture barrier and sealant behind them. Obviously they were installed without a permit; or pre-date the vapor barrier being added to code. Highly recommend adding a polypropylene vapor box on top of those lights and any other penetration into the attic space to eliminate such problems.
Enjoyed this - insulating seems so simple - but it is not simple at all - and it is almost never debugged. I think a lot of insulation is ineffective as a result.
5:26 Matthias filming a new horror movie.
Executive producer: Rachel and the kids 😂
Every time you flush air will be drawn into the system. What if you insulate all of the copper vent that passes through the attic. What type of ventilation do you have in the attic space. Is there a ridge vent or just the gable vents. Is there a fan? Is there a bathrood vent fan that exhausts through the attic? Many of those are supplied with cheap plastic hose which will deteriorate over time. If it did or the duct became disconnected moisture would be pumped into the attic space.
3:08 reminds me of the renegade air conditioning specialist in the movie "Brazil".
Looks like the vent comes up thru the partition wall which all your roof rafters are point loaded down to....that wall is probably not insulated, and the lumber has a relatively low r value carrying heat up into the space and into those rafter braces....meeting the cold air and condensing on each of those 2x4s. Probably before the blown in insulation at those points.
I wonder if your use of the basement shop space (as opposed to rarely-visited/uninhabited storage before?) could have contributed more warm/moist air up that pipe chase? Would just be one human's worth of moisture -- wonder how much vapor a person emits per day. Could sealing it off from the bottom (where you stuck a stick/towel up it) prevent enough moisture from rising up there in the first place? Of course, then you know even less what's going on up in there, whereas if you leave it open and it drips on you again that will be a good sign you need to re-investigate. Looking forward to the follow-up!
I bet with ABS plastic you wouldnt have had that problem. The copper is such an incredible heat sink.
Makes me glad that my 100 yr old house has the sewer pipe leave through the wall with the length of the vent pipe running up on the exterior. Maybe only works here in Vancouver though with our mild winters to prevent freezing.
With Vancouver weather, there would not have been an issue in the first place
That long pipe up to the roof (vent) wouldn't have cold air falling down it if there was a sewer trap. This is where the pipe goes down and then up to trap a portion of water that prevents drafts, but still allows venting of sewer gasses. Similarly, a lot of buildings have floor drains that have these traps, but if the drains aren't used to drain water very often, the trap water dries up, which allows a draft from the sewer which you can easily smell.
If this long section of pipe that gets cold has a trap, but you don't use the drains or flush the toilets on that stack very often, the trap could be drying up allowing a cold air draft down that pipe, which would enhance condensation build up. Just a guess
Wrap fiberglass batting insulation around the pipe and secure it with tuck tape. The problem will continue to happen because when the pipe is in use, cold air is drawn in and cools the pipe, any moisture around it will condense on the pipe. When the pipe warms back up from the heat in your home it will melt and run down the pipe. You were correct in foaming but to fully remedy this the pipe needs to be insulated.
I had a similar problem with dripping water from the vent pipe. I found a very small crack on the joint, where the horizontal vent pipe was connected to the main one. The water was sipping from inside of the vent pipe and goes down. I would suggest you to check that as well.
Wow, crazy... I'm surprised this is the first I've heard of this: I live in a newer house now, but lived in an older one with metal dwv for several years...
Lot of people mentioning vapor barrier, which I guess can be good in the attic behind drywall, but I've found in a basement storage area, vapor barrier against the insulation was just causing condensation and mold in the insulation: presumably wasn't sealed off enough to prevent all humid air from entering, so instead just provided a place to condense and an impediment to removing moisture...
There's always a right and a wrong side of the insulation to have the vapor barrier on, but in a lot of instances what's right in heating season will be wrong in cooling season
These are top shelf visuals
This is the first time a youtube video made me itch...
Installing or having to get back into that white fluffy stuff is like a vacation compared to regular fiberglass or cellulose. That's my preferred attic insulation as long as I don't have to pay for it
I love these videos
they encourage me to fix my own stuff
With a little commitment, you can do at least as well as the average professional would do. You won't do it as quickly, sure, but you'll save a ton of money and know exactly who to blame if it's not perfect. The consequence is you'll start finding flaws in nearly any professionally done repairs which were either missed out of negligence, or just skipped because it's something the average homeowner will never notice anyways.
Like you said at the end, that a vapor barrier will help. Especially installed on the warm side of the insulation.
It has a vapour barrier, if it didn’t I would have said so.
@@matthiasrandomstuff2221 My apologies I thought you said it didn't have one. Still an essential part of the overall construction of the house that tends to not be done right, if its installed at all.
I did enjoy it thanks! My house was built in '68ish, while i havnt noticed much leakage this kinda makes me want to go up and check around the attic.
Thank you for sharing the house debugging! Do you think the cold would conduct as far down the pipe if the vent stack were PVC?
Great sleuthing and I hope to see a follow up about it.
Interesting stuff. Well done once again.
Architect here - how many roof vents do you have? A common problem if you don't have enough roof ventilation is moisture accumulation which would leave the marks your seeing - warm humid air rises through every opening in the ceiling, it condenses, lands on the insulation, then gets absorbed when it warms up and the wood toughing the insulation absorbs it. From the pattern it looks like the water marks line up with your insulation suggesting it's a current issue. In terms of ventilation, Not only do you want flapper vents (at least 4 or more depending on the size of your roof) but you also want to double check that there are baffles adjacent to your soffit vents. If the blown insulation guys didn't install baffles, the humid air that gets into the attic will have nowhere to go - the soffits pull in fresh air and wind blowing outside sucks it up through the roof vents. Blown insulation is notorious for blocking them.
You're correct about vapour barriers but every single pot light will let humid air into the attic - especially that box you revealed which should really have a VB shroud around it. You can VB the ceiling with any coat of paint that has a rating of
We all have leaking roof or condensation proplems in the atic that are not easy to fix.
Good catch that "leak" was a ROYAL PITA!
Now it needs to be rechecked on a really cold week or two.
I miss your frequent videos.
Some years ago, I heard someone mention that a pin hole in the VB can produce a cup of water per year.
I believe the cause of this is the cold pipe itself, not the air escaping from the room - without vapour barrier the air is finding all, even microscopic gaps in the constructions. Another problem is the insulation - it is said the natural fibre insulation, like the cellulose wool will absorb the moisture, as opposed to glass or mineral wool, what will be wet in the touch, as in your case. I would be tempted to try to insulate the pipe itself in the attic.
Moistening of the insulation over the course of the winter is a total normal ocurrance. It only becomes a problem when the evaporation rate in the summer is less than the condasation rate in the winter. Then water would build up. But if that's not the case, you are good to go.
adequate ventilation in the roof space will sort that too :) great video as usual
I love these house debugging videos! 👍🏼
Would a thermal camera give some insight debugging moisture problems?
It can show you the cold spots in a room, which might indicate a cold bridge, a low level of insulation or air leakage. They might also act as condensation points. If that condensation cannot get away through ventilation you'll get mold.
My house was built before 1840. If Matthias went on an investigatory adventure here I suspect we'd never see him again!
Forget expeditions into darkest Africa, your house has darkest everywheres.
Nice explanation. Thanks
What do you think about more roof vents to let out moisture before it condenses ?
Roofing pros seem to suggest much more venting now than they did decades ago too.
Those are a good idea, but wouldn't help with this particular case. The condensation happened in the insulation, before it really got to the attic air.
With that big pipe sending cold down in the hot moister air lower down I guess there will be condensation below the new foam seal as well.
Yes, there will be some condensation on the pipe itself, but as long as there isn't air flow, there will only be so much condensation.
Berra, there is no renovation solution at this point, only mitigation; but the mitigation can throttle down (maybe never off) most of the moist effect.
Is that a metal soil stack? This seems like it's designed to eventually fail (via condensation and chemical corrosion). I'd swap it out for lovely, non-conductive PVC.
Yes, after a few thousand years, that coppper will fail
@@matthiasrandomstuff2221 The vertical section, yes. The horizontal sections, far sooner, particularly where sewer gas accumulates at the top of the pipe cross section. This is far more prevalent on legs where there isn't a good draft and the gas stagnates. The pipe will deteriorate at the top and effectively turn into a gutter. You'll know it when you start smelling sewer gas, or when the pipe fills up from the inrush of a toilet flush and leaks over.
I live in the uk my house is 20years old if it snows I get condensation dripping from the roofing felt thankfully it doesn’t snow that often
You want an air barrier more than a vapor barrier inside your house. Drywall is a good air barrier. It is not a huge job to close up the gaps, but it will be a dirty day. Building Science Corp is a great resource if you want to go down the rabbit hole of vapor diffusion, air sealing, case studies, etc
Make sure to have negative pressure ventilation. Especially in winter. That is, lower pressure inside than out. Otherwise you will get problems with condensation. In the old times chimneys were warm and provided this negative pressure from the draft. Today with less burning, extra fans, always on, for the kitchen and the bathrooms might be needed.
Sounds like a great idea. Keep negative pressure inside an old house so freezing cold air can infiltrate through every little leak.
Yes, better than warm inside air getting things moist at every little leak
@@mckenziekeith7434 Yes, indeed it is a great idea. It is how houses was built for centuries, if not millennia. With a fire inside and some form of chimney, negative pressure inside is what you get. With modern heating that doesn't consume air, you get positive pressure, condensation, mold and rot. You need just enough forced negative pressure to ensure it never becomes positive.
@@adoby83 I guess I was wrong. But I still think the best idea is to have a well sealed house so that warm air can't easily escape and cold air can't easily infiltrate. But slight negative pressure would seem to be better than positive in cold climates. I don't necessarily hold up old houses as the best examples of thermal design. Often they were designed with the idea of running huge roaring fires in huge fireplaces to keep warm. I live in a mild climate so don't have to worry about these things as much.
tricky one... good diagnosing
Really enjoyed this video 👍🏻
Best thing is to continue monitoring it and place pieces of paper with dates on them under the original leaks! - Museum professional
is it possible the humidity level in your house is higher than normal? maybe need a dehumidifier or something? thanks for sharing.
Hi, I think I may have a similar problem in my house. Did you ever confirm that this solved your issue?
If you have frost in the attic you might also check exhaust fan leaks.
You should stuff some insulation in the gap in the basement where the vent pipe goes up. The warm air in the basement is using that space like a chimney.
Yes, I did that too. Sprayfoam would be better, except then I really wouldn't be able to get at it anymore!
Look at all that glorious copper!
Eh, it's not so glorious when the sewer gasses eat holes through the top of it in horizontal legs.
Hot air contains more water than cold. Cold air is heavier than hot. Hot air rises. Hot air rises from bathroom, kitchen, breath, shower etc.
The warm air seeps up in the insulation, but when the temperature drops, the air cannot hold as much moisture.
Then condensation occurs.
The type of insulation you have cannot store the moisture.
Cellulose or others
Wood-based insulation types can absorb moisture
Your problem is because you do not have a vapor barrier.
That looked like an expedition !
Interesting problem, I'm not used to seeing copper stacks, so maybe that's why I've never heard about it.
Old homes I work in tend to be from the late 1800's to the early 1950's, and they have cast iron and lead drain lines. Newer homes I work on tend to be 1970's+ and they all have pvc or abs drain lines.
The few times I've worked on 60's homes they've all been a nightmare because of aluminum wiring and galvanized water supplies.
That stack is cut pretty tight, It's not uncommon to see a big chunk cut out of a 2x6 wall for the stack to poke through. Looks like a well built home.
I don't know how much you care about code, but here at least, an inspector would cry that you didn't use fire block foam. The difference? Who knows! but it's slightly orange.
Not that any inspector will know when it was done, and it's an obvious improvement over what was already there.
Today on This Old House: Some maple nerd sprays spunk all up in his attic, we'll have Richard "Full City Water Pressure" Trethaway help him out when his flight lands.
Hi hallo, Sorry wenn ich mich da nun dazu melde aber......... But copper is a very good heat conductor. The problem with the moisture comes from the fact that cold air "flows" in the pipe and around the copper pipe the heated air condenses on the cold pipe and drips down at the bottom. Cold air still flows down from the top of the duct At times so much that puddles of water can form on the bottom, there are two ways to solve the problem and keep the moisture in areas, one is the shaft where the pipe goes up completely to the outside of the roof against a thick-walled plastic drain pipe swap, or to wrap the copper pipe with a felt insulation tape, but I recommend swapping the copper pipe for a HT pipe and completely insulating the shaft with insulating wool........ grüsse aus Berlin
Just wondering if you know what type of insulation you have in the attic. I have the same kind and I always wondered if it was asbestos?
No, that white fluffy stuff is a modern fiberglass product, and the yellow fluff is almost certainly just an older fiberglass based blown in insulation. The more common type to likely contain asbestos was vermiculite, which was a mineral based loose fill resembling a very light weight kitty litter.
Dale Gribble Thanks I feel better about going into the attic!