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Glad you enjoyed it!

Thanks! I took a look at the pics and you have a pretty standard Cape design home. I'd say their overall approach is good, with one caveat I explain below. If they spray foam the underside of the roof in the knee wall spaces as well as the exposed gable end walls inside the space that will make those spaces "conditioned spaces." That will eliminate the need to do any air sealing in those spaces. If they then dense pack the slope bays and air seal / insulate the upper attic space that should produce a good solution (it sounds like you have good ventilation in the upper attic). The only question I'd have is what type of spray foam do they want to use on the underside of the roof? In my opinion and the opinion of many others in the building science community, the ONLY type of foam that should ever be used for insulating the underside of roofs is closed cell foam. This is because closed cell foam at 2" thickness creates a vapor barrier. Most companies use open cell foam because it's faster/ cheaper/ easier and the homeowners usually aren't aware there's a difference. However -- open cell foam does NOT have a vapor barrier. And water vapor can migrate through it, get trapped against the shingles and rot the roof. I have worked on jobs where this has happened and have dealt with the after effects. It is not a myth. Closed cell foam is more expensive, but I would not want to play with my roof. We don't use closed cell foam in these situations because it's prohibitively expensive and I simply don't like the idea of a roof having a coating on the underside of it if it can be avoided. At least 25% of the attics we work in have a small roof leak somewhere that the homeowner was unaware of. A well ventilated attic will tolerate small minor roof leaks (it sounds crazy but we see it all the time). Heck I have a video showing an example of this. If you have foam sprayed onto the roof there's a solid chance you're not going to know you've got a leak until you've got a real problem (happened on the project that I worked on). If they use open cell foam you may never have a problem (at least not that you'll be aware of for several years). It is just not what's recommended. I'd recommend having them quote you for closed cell foam on the underside of the roof. But first DO your research on this...google closed cell versus open cell foam when applied to roofs and you'll learn all that you need to. You may also learn that you want a different contractor in the process (but hopefully not). Hope this helps! Andy

@@insulwiseenergycomfortsolu3293 thanks so much for your thoughtful reply!! Super helpful. One quick follow-on question to this-we were thinking of not doing the spray foam, so out of the contractors plans-what would you suggest they do if they don’t do the spray foam, but something else? Do what you did in this project in the video where you leave that roof line untouched and then just do batting on the knee wall and the cellulose spray foam in the bottom? We would like to keep our crawl space semi-workable for storage so the cellulose spray in on the bottom were on the fence about… Thanks Andy!

@@agacom1 You're welcome! If they did the same thing in your Cape that I do in this video you'll have a fine result. Batting the knee walls with R-19 fiberglass and covering them with a building wrap is the easy part. The other critical things are sealing the voids underneath the knee walls, air sealing the outlets in the knee walls with foam / caulk, and air sealing all of the air leaks in the floor of the knee walls before insulating with cellulose. Lastly, if your knee wall spaces are not vented via soffit or under shingle vents, they should be vented using something like the slant back vents that you see me use in the video. You never want to have an insulated, unconditioned space that is unventilated. It becomes a perfect situation for mold growth. Hope this helps! Andy

Thank you! When I first started doing this I would climb down into the voids and seal the exposed stud bay openings, misc penetrations like outlets, then batt the walls and floors with fiberglass, and finally staple tyvek over the studs. The problem is that it's extremely time consuming as well as somewhat dangerous. It's more difficult than it looks working on a sloped space in a tight area and trying to get everything right. I was sure I'd have an employee loose their footing at some point and fall through the drywall of the stairwell slope -- and then down a flight of stairs. In terms of heating and cooling that space, the act of sealing the top of it this way already makes it far more energy efficient than it was prior. It would be my bet that the difference between capping the void and perfectly air sealing and insulating the interior of it would be almost impossible to notice on utility bills.

@@insulwiseenergycomfortsolu3293 Thank you for the long and detailed response, i 100% agree that the cost and effort far out-weigh the reward. Id be a terrible client... lucky i do it all myself haha.

Its not wasted space. At best you could put a few shelves in but who wants objects on shelves above them as they are walking down a stair case? The cost making that space usable for such little return is where the true waste is and that is why its like that. - Carpenter.

@@judge462 also what you trying to say thats gonna cost to board in a box ? itll cost the price of like 2 extra plasterboards if that you probably still got enough left over since you just built an entire house out of the crap and the price im already paying for a shitty wooden house is through the roof so yeah gimme that shelf space, its way more useful than an un usable cavity

It is a bit of a waste and some homeowners do recognize this and build shelves that go into the space. 99% of the time homeowners are completely unaware that these large voids exist in their attic floors.

In Pittsburgh stairwell voids are always treated this way.

@@infertilepiggy5667 It would require loads of extra framing and finishing as well. A simple set of shelves on the under side of a stair case might raise the cost by $3-4k here in Australia... i assume maybe 1-2k in the US. All for a potential health hazard.

You could do that and then make your sealing plane on top of the floor joists. But you then would need to cap the ends because there will be a gap. Also, the fiberglass is almost always loosely attached and partially hanging down into the void. Best practice is pulling the existing glass, sealing between the joists, and then insulating over top of the new plane (IMO). Andy

Installing this foam panel and then air sealing it will cause this to function the same way as the drywall ceiling would on the rest of the attic floor. Now, if we did not insulate over top of it, it's possible the surface could get cold enough for water vapor inside the stairwell void to condense on the underside of the foam board. But because we later added 15" inches of cellulose insulation on top of the foam board, it should not get cold enough inside that void for water vapor to condense on it (just like on any other ceiling surface that's below an attic in your home). If you have other questions fire away. Thanks! Andy

@@insulwiseenergycomfortsolu3293 Thanks Andy!

Thanks!

In this case the upper attic area was large enough that we were able to cut a hole in the ceiling and enter that way. We then patched the ceiling afterward. Sometimes these upper ceilings are just too small though. If they are less than 6ft across than we will usually have to blow the upper attics by tubing up through the slopes and blowing those areas that way. It always depends on how much room we have. Thanks!

@@insulwiseenergycomfortsolu3293 Thanks for the reply! I have this situation and was wondering what the best course of action would be. May need to snake a camera up there to do an inspection before I cut a hole. I have a dormer as well that connects to that area and it would be best to have access to it.

Sounds good, I've heard that turbines really move a lot of air. Do you have a source of intake ventilation for them?

@@insulwiseenergycomfortsolu3293 Yeah I have soffit vents. So far having only the turbines is working well. Humidity in attic dropped a bit and attic is now only 10-15F more than outside.

Thanks for commenting, yes you'd still want to seal them. You want to keep the heat that forms in those knee wall attics from pushing between your floors. It will also help to cool your home more efficiently by not allowing air conditioned air to escape into the knee wall spaces. I'd definitely recommend this step. Hope this helps! Andy

@@insulwiseenergycomfortsolu3293 Thank you appreciate the reply. I'm going to seal them with foamboard like you showed. Will also pull the fiberglass batts and airseal with foam. Might also replace the fiberglass with mineral wool batts depending on cost.

Interesting, I haven't seen a pipe used to draw air from lower in the attic, but that would probably work better than having the fan opening situated directly next to the ridge vent as it is here. Thanks for commenting!

Thank you! The kraft paper doesn't work even in the slightest as an effective vapor barrier, from what I have observed. What should be your vapor barrier is your drywall ceiling with a few layers of paint, and then having all of the penetrations / air leaks in your attic floor sealed with foam before you re-insulate. I have seen rock wool becoming more popular lately, if you have a minute could you let me know why you're looking to use that versus something like cellulose insulation? Thanks, Andy

Thanks Jonathan! Glad I could be of help. Yes leaky ducts, both supply and return, are often enormous energy wasters in homes and also tend to contribute to poor interior air quality. We find disconnected supply ducts all the time when we do our AeroSeal duct sealing jobs. It's incredible. And the degree of improvement that you can make for a few hours of time and likely less than $100 in materials is often surprising. Nicely done! Andy

Glad it was helpful, thank you for posting a comment!

Glad it was helpful!

We did not remove the existing insulation batts. They were fiberglass and mold cannot "eat" inorganic materials. There were likely mold spores present in the material, but there are mold spores everywhere. The key is in making it impossible for mold to grow again in the attic space by 1) removing the moisture sources (air sealing the attic floor and venting the bathroom fans out through the roof) 2) making sure the roof is ventilated well enough so that if moisture does make its way to the attic that it can readily dissipate to the outside.

@@insulwiseenergycomfortsolu3293 ah, thank you for that info...

I would hire a try to hire an insulation team that understands insulating mobile homes. If you can get that attic better insulated, as well as properly ventilated, your home will be much cooler.

With roof ventilation you need to have both exhaust (ridge vent) and also intake (soffit, under shingle, or slant back vents placed down low on the roof). Also, how well is your attic insulated. In most cases the end goal is to keep the home cooler, not so much to keep the attic cooler.

When I'm not shooting video I absolutely do! Attic are nasty places and you don't want to be breathing that stuff.

Look at the guy in the back wearing the respirator. That is awesome! However, I see all that dust / insulation particles, and if there were ever animals in the attic, there were zoonotic disease potentials. Just because you are shooting a video doesn't negate the need to protect you or anybody in the attic. Lead by example, you sir are not doing so. When you are not looking, the other workers will say "awe it will only be a minute. He does it. Why can't you eat?" A muffled voice is better than a lung disease/autoimmune situation that can be avoided.😢 That coughing is a sign that your lungs be affected by the particles in the air. Listen to your lungs through your coughing.

That's too bad, if you have something that's working I hate to mess with it. However with full soffit vents and a ridge vent, you should -- should be just fine. That said, 30 years on a 3 tab shingle roof is outstanding!

I found this on heatinghelp.com. I'm assuming it's accurate, but always worth double checking. The 411 designation means that it's a 3 ton system according to this. Link for the page below: hope this what you're looking for Lennox equipment: 211= 1.5 ton, single phase 261= 2 ton, single phase 311= 2.5 ton, single phase 411= 3 ton single phase 413= 3 ton, 3 phase 461= 3.5 ton single phase 463= 3.5 ton, 3 phase 511= 4 ton single phase 513= 4 ton 3 phase 653= 5 ton 3 phase forum.heatinghelp.com/discussion/79636/lennox-model-numbers-starch Hope this helped! This was a weird one. Andy

Hi there, unfortunately we do not. But thank you for asking! Andy

Hey Kevdog thanks for the shout out! For your questions: 1) For air sealing qualities there isn't a shortcut, it has to be done with foam and every penetration sealed like you see in the video. No insulation type other than spray foam will accomplish this. 2) Batt fiberglass can work well in attics, but likely not as well as blown cellulose (with batts it's hard to avoid having some gaps). Best practice would be: a) Air seal the attic floor b) Install your first layer of fiberglass between the floor joists. c) Build your hatch wall and lattice for the storage pad. d) Install another layer in between the lattice joists. e) Attach your plywood to the lattice/ storage pad floor f) Install another layer of batts in the eaves/ outer roof slope areas so that they are about even with where the roof rafters rise up and clear the attic floor joists. g) Install another layer of batts running perpendicular to the attic floor. This gets you coverage over top of the floor joists and helps account for any gaps in your first layer. You want to fit pieces into the eave areas first (in between the roof rafters) because you won't be able to get another layer into that space just by running the batts perpendicularly -- unless you have a very steep roof). Hope this helps and if you have other questions let me know! Andy

Correct, I am biased. I previously installed injection foam for two different companies and witnessed it fail (shrink badly) on several occasions (within hours of the install in one case). I'll enclose a link of how this stuff looks after installation below. Our goal is to insulate the walls once and not have to go back. That is why dense pack cellulose insulation is the most trusted way of insulating closed cavity spaces within the building science community. Go to Chapter Failed Foam Injection at 4:48 in the video. ruclips.net/video/YsVCTGRR7fc/видео.html By the way, the customer paid the foam injection company about $7,000 to insulate the same areas that we are redoing in this video. So yeah, we're biased. Andy

Thank you for saying so! I can confirm that the design has been battle tested here for well over a decade of hot summers and cold winters. Glad it helped! Andy

Thank you 👍

Good question. Cellulose insulation basically just smells like paper, as far as I can tell. We air seal all of the attic floors that we work in prior to insulating them, so there really isn't much of a smell that comes down into the home. I've used just about every brand of cellulose insulation out there and it all smells pretty much the same to me. That said -- there have been a few cases of cellulose insulation being used as a damp wall-spray application in new construction and it was not allowed to dry properly before the drywall was put over it. I've heard of that creating a bad smell, but not cellulose on it's own.

Great question! By using a fill tube to inject cellulose into the stud bays, the good thing is that we actually find and locate the fire stops. We simply drill an additional hole above the fire stop and dense pack the rest of the stud bay above it. Andy

Hey there, yes the return ducts are usually not given any respect at all during the initial construction process and as a result they are often catastrophically leaky. The more that you can seal them, the more that return air will be taken from the upper living spaces of your home rather than the basement and garage. This will improve your interior air quality, comfort, and energy efficiency as the warmer air in those spaces is more efficiently pulled back to your HVAC system to be re-cooled. Andy

Thanks for commenting, you're spot on with the ceiling mounted whole house fan, except for that during hot days the thin aluminum louvers allow intense attic heat to radiate into the living space, and if you live in a humid climate -- the outside air getting sucked in will be unpleasant. I have seen roof mounted attic fans work to cool the attic, but the best solution is the one you mentioned --- air sealing and insulating the attic floor and making sure you have effective intake and exhaust passive ventilation. Andy

@@insulwiseenergycomfortsolu3293 Yep! I've never run the air conditioning in any of my homes unless requested to do so by visiting guests. FYI, I'm at 40°N latitude in the Midwest And, I'm not uncomfortable. It's all in the air handling. And a whole house attic fan? Not necessary. A couple of $20 box fans placed in windows with blocking so the breeze is blowing out, allow bedroom windows to be open for the incoming make-up air. Air sealing, eave vents, and lots of fluffy stuff! Here's a video on my take on DIY attic eave insulation baffles: ruclips.net/video/ZB346-ng_8Q/видео.html

Interesting, and I'm not surprised. If there wasn't sufficient make up air in the attic for that fan, it could also have been pulling air conditioned air directly up from your home. Now that -- is bad for a power bill.

No, this is a Frost King Aluminum Kerf Seal Door Set. Search that for amazon and you'll see it. I know the kerf inserts you mentioned and I've used them, but here the kerf seal is attached to an aluminum "frame" so you have something to attach it to the door frame with. Thanks for the comment! Andy

Why? We've performed these exact air sealing measures in thousands of homes to excellent effect. What's the gripe?

I was thinking I could pull the batt insulation , put the foam board in and put the batts back on top of it. Again, thank you!

In the video it doesn't matter which side the foil is on. We were using the foam board to block transition gaps beneath the knee walls and it was buried in cellulose insulation later. But-- if the foam board were to be exposed -- you would want the foil side to face outward. The foil covering will act as a radiant barrier, reflecting attic heat back toward the roof and away from the home. So I believe in your application you would want it facing outward. Hope this helps! Andy

For the best result you'd want to leave the batts in place in between the stud bays of the knee wall, and then go over top of the studs with foam board. You never want to have air gaps between the insulation and the surface that you're trying to insulate, this can allow for convection currents to occur. Andy

Glad you enjoyed it!

The product is M-D Building Products Camper Seal Tape 1 1/4" in W x 30 ft Roll. It's about $7 on Amazon. I just put these details into the video description. Hope it helps! Andy

We generally use 2x10's to build the box that the ladder folds up into. But you don't necessarily have to. You need about 3" inches of clearance between the top of the ladder when it's folded up and the top of the hatch wall. For lower profile ladders a 2x8 can work. Hope this helped!

@insulwiseenergycomfortsolu3293 it sure did, I'm new to this world, but I am going to try this out. Thanks!

If you make your lattice using 16" OC measurements between the floor joists, you can easily lay the batts between them before putting the plywood top on.

@@insulwiseenergycomfortsolu3293 yeah i started to realize you could go with lower r value to fit and then cross the next layer and put what fits. 🤪. Rack it up to amateur view, cant see it until explained. Thanks for quick reply. I already have bunch of r38 and am trying to think if how to do a small platform above that, only thing i can think of is running collar ties right above the current collar ties (finishing out attic space). If i do that it still would have about 3.5-4 ft in center. Just enough to store a few bins a christmas tree etc.

Generally we'd recommened 1) Air seal the attic floor and get all bathroom vents vented to the outside 2) Confirm you have adequate intake and exhaust passive ventilation (or add if needed) 3) Insulate attic floor to R-49 with cellulose insulation 4) If you still have heat penetrating down into the living spaces, then install a fan as a last resort. We like solar fans because you don't have to worry about the wiring part

Yes they are 2x10's, but you may be able to get away with 2x8's. The hatch wall needs to be about 3" inches higher than the ladder is when it is folded up inside the attic. For some people it is more challenging yes, but for most it's not an issue.

There are baffles because there are no soffit vents on this home. We installed a series of slant back vents along the back of the house for intake ventilation.

We top coat over blown fiberglass on a daily basis. The main issue is getting that attic floor well air sealed, good on ya for giving that a go!

It depends. If you previously had enough passive exhaust vents and they were balanced between intake and exhaust, (and your attic floor is insulated to at least an R-49 and ideally also air sealed), you should be fine without it. But --- if that fan was functioning as your only source of exhaust ventilation (sometimes it's done this way), then you probably need it back.

I'd recommend having a blower door guided air sealing team go to work on your home. I'd get the air leaks sealed in the attic floor, basement rim joists, around windows and doors, etc. We see plenty of houses that are absolute sieves...outside air is cycling through them at much higher rates than you'd want. When this happens it degrades comfort, energy efficiency, and also will introduce all kinds of outside air pollutants. I've included a link for how to air seal an attic that has already been insulated. Hope this helps! ruclips.net/video/PUSONSE7srE/видео.html&pp=ygUVaW5zdWx3aXNlIGFpciBzZWFsaW5n

If you needed to there's a process for finding those things. Sometimes we flag them, but yes it's going to take longer once they are covered.

If by rafter vents you mean soffit vents, than yes -- a roof power vent can work very well to cool down an attic (assuming that you have enough soffit intake vents to provide adequate make up air for the fan. If you do not, the fan will depressurize the attic and pull the air from the house. This is the last outcome that you want, but unfortunately a common one).

Hi there and thanks for the comment. During the winter months you're absolutely right. Your attic temp should be the same as the outside. However during the summer months, if the attic floor has been air sealed, properly insulated to R-49 with cellulose, and vented properly (we prefer using passive ventilation measures), it won't matter how hot the attic gets --- the heat should not penetrate into the rooms below. This is has been the consistent result that we achieve with our customers using our attic upgrade measures. Condensation / mold problems are not usually summertime problems. The attics get too hot and dry for wood to be consistently wet (at least from condensation). The roof power fans seem to be a cheaper way to cool the attic in the summer, which keeps the house cooler too if your attic is not properly air sealed and insulated. But the roof power fans, from what I have personally seen, do not offer much of an advantage during the winter here. The absolute biggest component of having a healthy, mold free attic during the winter months is 1) having a well air sealed attic floor 2) having bathroom fans vented to the outside 3) having enough balanced ventilation to allow for unplanned moisture to easily vent to the outside. Andy

@@insulwiseenergycomfortsolu3293 Thanks Andy, Thanks for your reply, You are right It really does depend on the temps of yoru atti. My attic over 150 degress that was drying out my roof decking. My company calls this the double bake, Bake from the top and the bottom. With overheated attics you will dry out your roof deckign leading to delamination of the plywood due to the high heat. And as you said if its too cold you get mold. I traded my 150 degree attic and went with a white silcone roofing coating. I cut my ac bill cost in half as the attic tempretures drop 30-40 degress, but now I have mold growing on my roof decking bottom. I am still working on trying to figure out the right solution for the mold. The attic space in only 3 feet high and there is 2 1/2 feet of blown in insulation. This was in 2008. If I could do this all over I would use foam. Thanks for your replay, David

@@insulwiseenergycomfortsolu3293saying it doesn't matter how hot your attic gets as a general statement seems wrong, if your HVAC is in the attic, it matters how hot your attic is. Your flexible ductwork, no matter how good, does not have R-49, and nether does your HVAC.

@@davidhazen2394 Hi David, 150 for an attic is awful hot, and if you've only got that much clearance between your roof and your attic floor it will radiate more heat downward toward your living space than the roofs that are taller and provide more clearance. I haven't seen too many issues of plywood delaminating in our climate here in Pittsburgh, but that could more of a factor in other areas. When I've seen it occur here the roof being wet, usually from long exposure to condensation has been the bigger factor. If you can get enough intake ventilation somehow, that should help with the mold. Also, I'm not sure if the attic was air sealed or not, but that will also be a factor with mold, at least it is here. Andy

@@insulwiseenergycomfortsolu3293 Thanks you for the hard work you do in helping me and so many others.

Is your attic floor air sealed?

@@insulwiseenergycomfortsolu3293 I would not think so; soffit vents, turtles and end cap vents still in place. Nothing above the insulation or on the backside of the slanted roof; do not know what is under the insulation.

Most of the foams are really pretty similar, we like regular Great Stuff for about $5k a can. The biggest difference is that it takes longer to cure than the more expensive foams so it can be messier until you get used to using it. But for an attic application all of them do pretty much the same thing.