I have no idea what truck you’re driving, but I really like your content. Grew up in KC and went to Mizzou. Glad to see the quality in one of my favorite spots on earth!
9:20 Maybe it's a different year of the code, but I live in Michigan in climate zone 6 and the code is R20 continuous and 0 cavity insulation, not R15 continuous. Also, I had an idea for a wall assembly that would possibly meet the R20 continuous with zero cavity requirements and was wondering what your (or Steve's) opinion was? The assembly would start with building a 24 inch on center 2x4 wall with no cavity insulation, then sheathing (preferably 3/4 inch plywood, but possibly ZIP) with a fluid applied or self-adhered adhered WRB membrane. Then I would attach 2x6 T-studs or similar to the wall studs on the outside of the sheathing and either spray approximately 4 inches of closed cell spray foam on the exterior, or attach another layer of sheathing (with another WRB) to the outside of the T-studs and fill the resulting exterior cavity with blown-in Rockwool. Finally, there would be some sort of rain screen/ventilation space, then the siding (I was thinking of either Hardy fiber cement board or cedar siding). My main concerns (besides the cost of that much closed cell foam) are that an inspector might not consider it to be "continuous" due to the small amount of thermal bridging from the dowels in the T-studs, the fact that T-studs aren't pressure treated and could be exposed to moisture in this use case, and that I don't know how the spray foam would fair being on the outside of the wood framing as it expands and contracts a bit throughout the year. It admittedly also feels a bit like a double stud wall with extra steps and less lost interior space. Thoughts on whether such a system would work or be destined to fail?
I rarely see videos on how to nicely handle corners or windows/doors when having exterior insulation plus a rain screen. I figured out solutions for my own house, but I'm certain there are better ways. I'd love to see a video on best practices with onsite details shown. The scenario where I'm least happy with my solution is when there's wind-driven rain that hits the windows. On my home, all rain that hits windows drains into into the rain screen. While that's not a terrible thing as it's a rain screen, I still don't like the volume of water that will get in there during major storms, as it will semi-regularly be challenge some of the tape flashing and take more time to dry. I would not have been okay with the solution if I'd used foam for the main exterior insulation, because I'd be perpetually worried water would wick behind the foam and cause long-term problems for the sheathing. One other discussion topic: What is a good siding system for homes with a rain screen and/or windows without a flange? Part of the issues I encountered were impacted by going with LP SmartSide, which I found frustrating because it was sloppy when it came to window openings with the rain screen or windows without a flange. (I love the EAS windows and doors we got BTW! Shout out to Steve Baczek who has done several videos on these windows.)
The conversation would be focused around total R value goal, team member skill sets and product availability. For our market Zip R is way easier to come by and install. In the NE rockwool seems easier and cheaper.
It also has to do with climate zone. In zones 3 and below, you’re safe to go with Zip R which is also the fastest and cheapest method because it’s sheathing and exterior (ish) insulation all in one. In climate zones 5 and above, it’s a real gamble to go with Zip R (and no additional ext. insulation) because your sheathing is below the dew point in heating season and you run the risk of condensation and eventually mold forming on or in the sheathing (see the ASIRI Designs RUclips channel for more on this). In these zones, you would be wise to use up to 4” of continuous exterior insulation outboard of the sheathing and adhered WRB. Zone 4 is a gray area (in my opinion) and should be considered on a case by case basis. Personally, I wouldn’t use Zip R in climate zones 4 and above on my own house because of the condensation risk.
Great info. I'm planning a build in Ohio and I'm leaning toward using 3" of mineral wool outboard and 5.5" of dense pack cellulose in the 2x6 stud cavity. I think that's an excellent wall assembly for zone 5. I don't like Zip-R due to the compromised shear strength with the thicker insulation versions.
I think if you look at the engineering available the compromise on sheer is negligible and most engineers aren’t concerned in our market. But of course, always do what you are most comfortable with.
How do you calculate where the condensing will be? I'm planning a 2*8 staggered stud wall with dense pack cellulose and then a couple inches of outboard rockwool (zone 6). One worry is if the condensing surface is inside the wall assembly and not outboard. How would one calculate how much outboard is needed in that case?
I’ve never done such a calculation, but I expect it would start by knowing the typical range of dewpoint temperatures for summer vs. winter. You can get the outdoor dewpoints from climate records. For indoor dewpoints, you can convert from your expected indoor temperature and RH, for summer vs. winter. Traditionally in northern regions, you put the vapor barrier inboard of all the insulation. But I’m in zone 5, and am thinking that even here, for summer A/C use, I want a small amount of insulation (like a layer of foam-board) inboard of the vapor barrier.
Hey Jake, what's your suggestion for finding contractors that have the knowledge and experience to complete an exterior insulation project? Even for people willing to pay a premium to implement these approaches, I've found it's extremely difficult to find companies that have any interest or knowledge to do them locally. Thanks!
There is a wall assembly calculator where you can play with different materials to see the dew point in the wall assembly at different temperatures outside. I came across such calculators in two European languages. In a German calculator you could switch the language to English
Jake, great information. Would really love it if you would use the medium of RUclips more effectively by inserting lots more videos and images of what you’re talking about (as interesting as it is to watch you drive around town in the ice and snow 😁). Those of us in the design and construction industry tend to be visually oriented and would really benefit from the extra time and effort. I’ll bet your Likes and Subscribes would skyrocket to the point where you could afford to hire a video editor so you could continue to focus on your primary business of home building while he/she inserts all the visual goodies. Win-win for everyone involved!!
That is a tough one, all of the continuous insulation methods I am familiar with require mounting surfaces that are close to traditional framing methods. You would need substrates like that of traditional framing to attach insulation.
Ford F series. Do you have any insight on Zip Rs cold weather performance being polyiso? I’m at 8000’ in Colorado where it goes below zero almost every night for a few months and I haven’t been able to find any documentation on zip r’s specific performance in cold weather. I’ve debated just going to a 2x8 wall. Also any thoughts on the typical Kraft faced insulation compared to the smart vapor barriers? Especially in my super dry 6b climate I can’t image much vapor diffusion happening if I have a very well sealed container exterior air barrier with the zip.
I’m in the same situation, 8600 park county. I’ve read zip r with wrb outside and continuous insulation behind that can lead to some condensation issues. I want to find some framers who’ve worked with stuff before. We are acting as our own GC, but all the experience husband and our architect have is not in our county and does not normally need continuous. So I am very curious on his opinion and your details too.
ZIP R is not vapor open and is therefore better avoided... unless you add enough - twice the R-value of the ZIP R sheet - extra insulation outboard (exterior). But to get rid of your moisture in winter time, you'll need to ventilate (which is not a big problem these days for new homes with an ERV).
zip r isn't exterior insulation. jake signs checks from huber who makes insulation in-board of sheathing. great product and nothing wrong with getting paid, just not apples to apples to actual exterior insulation. similar but not the same.
@@stevecrawford6958 OK, the main question becomes then: where to add the extra insulation in case of cold winters, on the inside or on the outside? Second question, what about the seams of the ZIP R-sheathing? These are not insulated and 100% vapor tight (ZIP tape)... In case of condensation, the OSB of the ZIP R-sheets become wet and you don't want that...
@@stevecrawford6958 The Zip-R insulation IS exterior of the framing. But IMO its two problems are lowered shear strength, and probably the bigger problem is that with it, you now have a framed wall assembly with vapor barriers on both sides. The foam of the Zip-R is effectively an added/unwanted vapor barrier.
As someone who has repaired my share of water damage over the years, i have a really hard time getting onboard with any system that puts insulation outside of the house sheeting.
@@jake.bruton.aarow.building We're just down the road from you guys, well, figuratively. When we built our own house in 2020 we went with 2x6 advanced framing with insulated headers. We tried to size and space windows and doors to eliminate unnecessary studs and cripples. Used Zip, and was very conscientious about air sealing and taping. Wound up special ordering full width tapes for window and door openings that nobody local carried. Did a full foamed envelope and so far are very happy with the way it turned out. Is it the best system? probably not. But it was a fairly economical system that wasn't hard to execute by someone with good Carpentry skills. I had just finished up a repair job where water had gotten behind 1/4" foam board under siding around replacement window flashing, and, oh boy, some of it was bad enough we wound up replacing studs and doing some mold remediation. Bad deal. Every detail has to be correct. These were tiny leaks around corner trim on replacement windows that didn't dry over time and caused a disaster. After the repairs, that house got fluid applied flashing, fluid applied barrier, and all new windows. It should be good now.
Videos at least for sound quality, in the truck are better than job site videos with all the echo off the walls. Makes sense as quiet driving experience is an automotive key requirement.
Wouldn't it stand to reason that exterior insulated sheathing like Zip R would compromise the structural integrity of the walls? The framing provides the resistance to vertical forces,, while the sheathing provides resistance to lateral forces. It takes the 2, together, to bond the structure. Traditionally the sheathing is bonded directly to the framing, resulting in a single cohesive timber structure. When you add something like an insulated backed sheathing, now the sheathing is not directly connected to the framing. The sheathing now has a stand off the thickness of the foam insulation, which obviously does not have the strength of the wood products, and now all of those lateral stresses are being directed into the fasteners that have a significant gap of foam between the sheathing and the actual studs that they mount to. There is no way that those fasteners are designed to take that kind of lateral forces when they are standing off the framing by an inch or more! I understand the rock wool "blanket" appears to be more of an insulated wrap over traditional structure, but the Zip R solution with the foam on the INTERIOR side seems extremely worrisome to me from a structure prospective.
The thicker the poly iso layer, the more reduction in shear strength, that's correct. But If this reduced shear strength is an issue or not depends on your location and design, Huber Wood has a table about this.
Zip R is used in western Oregon and Washington where seismic and wind load requirements are quite high. It’s all about the size, spacing, and type of fasteners. That said, it can very handy to use conventional sheathing (whether OSB or plywood) so you can use standard prescriptive fastener tables in the code, not worry as much about over-driven fasteners affecting the adhered WRB on the Zip, and then cover all your penetrations and required strapping with a fully adhered WRB and one or two layers of exterior insulation. Just depends on what you’re trying to accomplish and how you want to accomplish it based on the skills, expertise, and comfort level of the contractor(s) and crew.
@@MichaelJ674 That's basically the conclusion that I was coming to myself. Zip R seems to be much more focused on ease of installation for the contractors, at the cost of an inferior end product for the ultimate customer, as opposed to the other methods employed such as traditional sheathing with rockwool or insulating agent on the OUTSIDE of the sheathing, which would give you the best of both worlds. Traditional sheathing strength with added benefit of unbroken insulation layer exterior of the sheathing and studs. It sounds like everyone is confirming my suspicions, while saying that, yes structural integrity is reduced, yet still "safe" and within "code". I personally don't like that answer very much.
@@koenraadprincen7212 That was my fear. While I understand logically that something can be absolutely measurable, while at the same time statistically irrelevant, The idea just doesn't sit right with me. A better product should be better on all fronts. Maybe traditional sheathing is rated for 200mph, and the Zip reduces it to 180? Both are far and above any normal wind burst, yet both are far below any moderate tornado. Both would fare essentially the same in either conditions, so does it really matter? IDK, I just don't like the idea of it and maybe that's not logical on my part...
10:42 The rule of thumb is actually max. 30% *inboard* (and 70% outboard). In general it's better to use vapor open and moisture (wetness) tolerant materials in your walls (and to avoid plactic insulation material like EPS, XPS, Poly iso,...).
@@koenraadprincen7212 It’s a percentage so do the math to get whatever total insulation target you’re trying to achieve whether that be code minimum, passive house standards, or something else. Typically, that will vary by climate zone. The easiest formula is to fill your stud space with whatever kind of insulation you prefer and then add enough continuous exterior insulation to meet the percentages listed above.
@@MichaelJ674 Well, there is a difference if you're using vapor open or vapor closed insulation. Together with the amount of relative humidity you like for your living comfort. In general, it's best to place all the insulation at the outside (cold side) of your air (and vapor) barrier. If you're using a wool like insulation material like Rockwool, TimberHP, sheep wool, fiber glass, etc... it's even better to use two air barriers, one on each side of the insulation layer. Both air barriers must be vapor open, while the one on the warm side may be a bit lesser vapor open than the one on the cold side. When you're using vapor closed or vapor retarding insulation material like EPS, XPS, poly iso, closed cell spray foam,... you can do what you like (altough it's advisable to tape all the seams on both sides or at least on the warm side). Lots of what's told about Building Science on these different RUclips-channels comes from Joe Lstiburek and his concept of "The perfect Wall", but many people forget that his perfect wall in his lectures are based upon EPS/XPS insulation foam which is vapor retarding and can resist moisture. What works for one insulation material doesn't work for any other material.
ZIP R is not vapor open and is therefore better avoided... unless you add enough - twice the R-value of the ZIP R sheet - extra insulation *outboard* (exterior). To get rid of your moisture in winter time, you'll need to ventilate (which is not a big problem these days for new homes with an ERV).
@@koenraadprincen7212 I not certain where you are coming by your information but depending on your climate zone some places in the code actually require a vapor closed assembly. Further more a vapor barrier at some point in the wall isn’t really of any concern to me as the builder so long as we preserve drying potential in both directions from that impermeable layer. Zip doesn’t make a product approved for the very cold climates (according to code levels of insulation) and I probably would recommend using it above say climate zone 6 because of this. There are other methods that would work for less money and effort at that point. But the idea that something is vapor closed and therefore should be avoided isn’t correct so long as it is known that it is vapor closed.
Yes, there are much better options these days like Rockwool, TimberHP, flax, hemp, cork,... that will also help against overheating in the summer and that have better sound proofing qualities.
@@stevenbaczekarchitect9431 Not if you build the European way, that's: - Air barrier and vapor retarder on the warm side (that's inside when you have cold winters). - Insulation material (if possible with "moisture buffering properties"). - External sheathing that acts as an air barrier and that's more vapor open then the vapor retarder on the inside. - Additional vapor open insulation if needed. - If that additional insulation layer is not wind tight, add a vapor open facade foil. For example, an exterior grade wooden insulating fibre board like Gutex, Celit3D/4D,... is considered wind tight if you use the T&G sheets. - Air cavity. - Cladding or veneer (or even stucco with some changes). Done 🙂 In a hot and humid climate, you can make the outer air barrier more vapor retarding than the inner one, that's it. And that's problem with ZIP R-sheathing, it does not fit into the European style of building, regular ZIP can be used, if not too thick. In a hot or humid climate, ZIP (R) is better suited. But in climate zone 4, I would not use it as the winters are cold. In general: - In a *hot and humid climate* , your main air barrier and vapor retarder *can* be on the *outside* . - With *cold winters* , the main air barrier and vapor retarder *should* be on the *inside* .
@@koenraadprincen7212 OK, I will give it a try here.....why would I build the Euro way? I'm not it Euro. Do you know why they do what they do? Mainly because their base frame is masonry, not a wood frame. I have been to Europe a number of times and actually heading there real soon. I am very familiar with what they do, and why they do it. Why do you think it's better? I HATE the air barrier on the interior, makes no sense to me. The best air barrier in my opinion is a straight line. Displacing that line causes problems and headaches. In my early days we did ADA on the interior, and it was a pain compared to outside now. Why do really care? If I take a house to sub .60 Ach50 Pa there's no air moving across the wall, even with the AB on the exterior. The moisture buffering properties, yeah they may exist, but I don't think its at levels that will save a wall. So whats your external sheathing that is more open than my Siga Mayrex? Maybe exterior Gyp Bd - no thanks. Exterior insulation if needed ? When do you consider it needed? I think always?? Gutex or wood fibre? How are you economically attaching that? How are you trimming out those windows? How do the windows connect to your interior Air Barrier? I know these answers because I have done them and are doing them. It is not easy, It is not cheap, It is not common - it is a challenge. Air cavity - agree 3/4"......As for Zip, it isn't sold in Euro, so good thing. I'm not trying to be a jerk here, I actually agree we build crap in this country for the most part - commonly it is a very low standard to what we know. Building perfect Building Science is costly, for some hard to understand, and execute. There needs to be a "sweet spot" found, to which I search for on every project...... I would say I have been around the block, actually more like around the country.....I'm not bragging, just stating fact. I have designed some of the most efficient Building Science Friendly homes in the country. It's not easy, and I am always thinking - always!!! I appreciate your comments, really do, but I don't think you appreciate the challenges you have outlined above. Lastly, many have been referencing other videos, and people - here's a thought for you, because I know most of them. You ever wonder why those that speak "perfect" Building Science make videos and talk about it? But they don't do it, they don't have their projects illustrating their ideas, they don't have test results from their projects. They don't have referenced conversations with contractors and such, because they don't build - Building Science is an Academic Exercise for them, and that's fine, but before they come to the table to talk about what to do, maybe they should "do" something. Please do not take offense I am having a conversation with you, and being brutally honest with you, that's who I am. Like I said, for the most part I agree with you (except maybe the interior air barrier - just doesn't make sense). Now you got me fired up, it's 2am and I won't be able to fall asleep for a couple hours lol - thank you for joining in.
@@stevenbaczekarchitect9431 Sorry to have kept you awake ;-) *About "Euro-style"* Besides brick masonry, wooden framed houses have become quite popular in Western-Europe. In my discussions I'm always comparing apples to apples, so Euro wooden framed houses vs North Americain (NA) wooden framed houses. (As a side note: in Europe the walls of wooden framed houses are almost always prefabricated, framing on-site is rarely done). In general, sprayed foam is in Europe almost never used to insulate walls or roofs (only for floors). And you won't see it used in wooden framed houses, as Europeans consider wooden houses as "healthy" (that is why natural building materials are popular for people building a wooden house in Europe). *About Building Science (BS)* The physics in BS is the same everywhere in the world. The differences are in the way they *can be* applied in practice, because as you know, the building trade is very conservative ("we have done it this way the last 30 years"). I've seen most - if not all - of the lectures of Joe Lstiburek on YT about his "perfect wall", I like his concept about the different control layers and - *as a concept* - his wall is indeed perfect. But you can not translate that concept "one on one" into the real world, a lot depends on the materials used and the interaction between the control layers. His concept works fine for EPS/XPS/Poly Iso/... but not for any vapor open insulation material, not to mention materials that are also not water resistant. *Building Practice* One of the main differences between Europe and NA, is that in Europe *most of the time* , the (OSB-) sheathing for the shear forces ("racking") is on the *inside* , that's the warm side in winter time. That way, the sheathing doubles up as an internal air and vapor barrier, just tape of or caulk the seams. So, two of Joe's control layers are on the inside. Advantage: the insulation will be at the cold side of this sheathing, so there's no risk for condensation. (It's actually like flipping the ZIP R-sheathing to the inside). Disadvantages: a. You need a good quality of OSB as not every OSB is/was air tight. b. You need an extra "technical cavity" (about 2") for electrical wiring and (small) plumbing (but this cavity can also be filled with some extra insulation). c. Connection with the ceiling or floor beams of the second floor can be cumbersome (in order to keep the continuity). But this problem can be solved by using balloon framing. For windows and doors, it doesn't make a big difference if your AB is on the in- or outside. At least, not when using European style windows. When using a typical flanged window, an external AB is easier to guarantee the continuity of all control layers (except thermal). I agree with you on that one. European wooden framed walls always get - at the outside - a *VAPOR OPEN* facade foil or a vapor open (insulating wood) panel (like Gutex, Celit 3D or 4D,... or TimberHP in the USA). *This exterior foil or insulation must be able to act as a water control layer* . We always make sure that our wooden framed walls (and roofs) are vapor open to both the in- and outside. This is the reason why ZIP R-sheathing won't have a chance in Europe as it's to be considered vapor closed. *Getting the best of both continents* I think we both can learn form eachother... The ideal solution is quite easy... The regular ZIP panels - those without the poly iso layer - have their advantages: a. They are guaranteed to be air tight due to the WRB layer (green/brown), which is/was not always the case with regular OSB. b. They are vapor retarding. c. They can be used as weather protection. In Europe, this would be the perfect air barrier...and maybe that's the way we should look at it, let's put our AB to the outside as in NA but apply the European insulation logic to it. As you said, external continuous insulation (CI) is always a bonus. (It's even mandatory in some states). So this leads to... *The perfect wall for NA and Europe* - Frame the walls as usual, but take the minimal size (as needed per code or as stated by the architect/engineer for stability reasons). - Apply external structural sheathing and treat this as your air barrier and vapor retarder. Regular ZIP panels are a good choice. - Apply a *VAPOR OPEN* *external insulation* (thickness as needed per code or as wished). - Apply some additional insulation between the studs but with a R-value of max. 50% of the R-value of the external insulation. *If you keep the inner R-value below 30% of the outer Rvalue, NO extra AB or vapor retarder on the inside is needed (in CZ-4)* and you can choose a material rather for their properties regarding moisture buffering, sound proofing, air quality, thermal inertia,... so good candidates are sheep wool, wood fibre, flax, cellulose, cotton,... - Finish the inside as usual (sheetrock). - Finish the outside as needed by the manufacturer of the insulation material (i.e. facade foil as water control layer) and as needed for the final cladding or veneer. - Done In short, do as Jake is telling in this video but use regular ZIP i.o. ZIP -R-sheathing (unless you're building in CZ 1 to 3).
It's cool when you're doing a video in your truck, but sometimes a few subclips with pictures/graphs would help me understand easier.
I hear you. This one totally needed B-roll. I’ll try better in the future.
I have no idea what truck you’re driving, but I really like your content. Grew up in KC and went to Mizzou. Glad to see the quality in one of my favorite spots on earth!
Ford f series
The way the door panel trim dips down at the front in order to see the side view mirrors is a dead giveaway
Z-gerts are a great option for exterior insulation and an added thermal break
9:20 Maybe it's a different year of the code, but I live in Michigan in climate zone 6 and the code is R20 continuous and 0 cavity insulation, not R15 continuous.
Also, I had an idea for a wall assembly that would possibly meet the R20 continuous with zero cavity requirements and was wondering what your (or Steve's) opinion was? The assembly would start with building a 24 inch on center 2x4 wall with no cavity insulation, then sheathing (preferably 3/4 inch plywood, but possibly ZIP) with a fluid applied or self-adhered adhered WRB membrane. Then I would attach 2x6 T-studs or similar to the wall studs on the outside of the sheathing and either spray approximately 4 inches of closed cell spray foam on the exterior, or attach another layer of sheathing (with another WRB) to the outside of the T-studs and fill the resulting exterior cavity with blown-in Rockwool. Finally, there would be some sort of rain screen/ventilation space, then the siding (I was thinking of either Hardy fiber cement board or cedar siding).
My main concerns (besides the cost of that much closed cell foam) are that an inspector might not consider it to be "continuous" due to the small amount of thermal bridging from the dowels in the T-studs, the fact that T-studs aren't pressure treated and could be exposed to moisture in this use case, and that I don't know how the spray foam would fair being on the outside of the wood framing as it expands and contracts a bit throughout the year. It admittedly also feels a bit like a double stud wall with extra steps and less lost interior space. Thoughts on whether such a system would work or be destined to fail?
Incredibly well-spoken! Thanks.
I try my best to communicate these concepts in a way that anyone can understand. Thank you for the feedback.
Jake Littleman with Glasses Loves you !!!!! You the man!!!
Thanks for the education Jake!
I rarely see videos on how to nicely handle corners or windows/doors when having exterior insulation plus a rain screen. I figured out solutions for my own house, but I'm certain there are better ways. I'd love to see a video on best practices with onsite details shown.
The scenario where I'm least happy with my solution is when there's wind-driven rain that hits the windows. On my home, all rain that hits windows drains into into the rain screen. While that's not a terrible thing as it's a rain screen, I still don't like the volume of water that will get in there during major storms, as it will semi-regularly be challenge some of the tape flashing and take more time to dry. I would not have been okay with the solution if I'd used foam for the main exterior insulation, because I'd be perpetually worried water would wick behind the foam and cause long-term problems for the sheathing.
One other discussion topic: What is a good siding system for homes with a rain screen and/or windows without a flange? Part of the issues I encountered were impacted by going with LP SmartSide, which I found frustrating because it was sloppy when it came to window openings with the rain screen or windows without a flange. (I love the EAS windows and doors we got BTW! Shout out to Steve Baczek who has done several videos on these windows.)
Very informative. 🇨🇦
what is the most economical? Zip R or Rockwool comfort that on the outside
The added benefit of sound reduction with rockwool is excellent, likely worth the extra cost depending on your neighborhood.
The conversation would be focused around total R value goal, team member skill sets and product availability. For our market Zip R is way easier to come by and install. In the NE rockwool seems easier and cheaper.
It also has to do with climate zone. In zones 3 and below, you’re safe to go with Zip R which is also the fastest and cheapest method because it’s sheathing and exterior (ish) insulation all in one. In climate zones 5 and above, it’s a real gamble to go with Zip R (and no additional ext. insulation) because your sheathing is below the dew point in heating season and you run the risk of condensation and eventually mold forming on or in the sheathing (see the ASIRI Designs RUclips channel for more on this). In these zones, you would be wise to use up to 4” of continuous exterior insulation outboard of the sheathing and adhered WRB. Zone 4 is a gray area (in my opinion) and should be considered on a case by case basis. Personally, I wouldn’t use Zip R in climate zones 4 and above on my own house because of the condensation risk.
Everything has its pros, and its cons. Installed right should be the first concern.
@@paybax certainly a pro
When adding the wrap insulation outside on an older house, what happens to the window frames?
Great info. I'm planning a build in Ohio and I'm leaning toward using 3" of mineral wool outboard and 5.5" of dense pack cellulose in the 2x6 stud cavity. I think that's an excellent wall assembly for zone 5. I don't like Zip-R due to the compromised shear strength with the thicker insulation versions.
I think if you look at the engineering available the compromise on sheer is negligible and most engineers aren’t concerned in our market. But of course, always do what you are most comfortable with.
@@jake.bruton.aarow.building Thanks for the feedback.
Where is the link to sign up for the newsletter?
How do you calculate where the condensing will be?
I'm planning a 2*8 staggered stud wall with dense pack cellulose and then a couple inches of outboard rockwool (zone 6). One worry is if the condensing surface is inside the wall assembly and not outboard. How would one calculate how much outboard is needed in that case?
I’ve never done such a calculation, but I expect it would start by knowing the typical range of dewpoint temperatures for summer vs. winter. You can get the outdoor dewpoints from climate records. For indoor dewpoints, you can convert from your expected indoor temperature and RH, for summer vs. winter. Traditionally in northern regions, you put the vapor barrier inboard of all the insulation. But I’m in zone 5, and am thinking that even here, for summer A/C use, I want a small amount of insulation (like a layer of foam-board) inboard of the vapor barrier.
You can try to use the "Glaser method".
Hey Jake, what's your suggestion for finding contractors that have the knowledge and experience to complete an exterior insulation project? Even for people willing to pay a premium to implement these approaches, I've found it's extremely difficult to find companies that have any interest or knowledge to do them locally. Thanks!
It is absolutely tough. I would contact an energy rater like a HERS or BPI certified pro, they will know who in the market is doing the work.
There is a wall assembly calculator where you can play with different materials to see the dew point in the wall assembly at different temperatures outside. I came across such calculators in two European languages. In a German calculator you could switch the language to English
Its too bad we cannot build homes and buildings like thermos bottles with a vacuum wall insulated structure.
we can, just not cost effectively
Jake, great information. Would really love it if you would use the medium of RUclips more effectively by inserting lots more videos and images of what you’re talking about (as interesting as it is to watch you drive around town in the ice and snow 😁). Those of us in the design and construction industry tend to be visually oriented and would really benefit from the extra time and effort. I’ll bet your Likes and Subscribes would skyrocket to the point where you could afford to hire a video editor so you could continue to focus on your primary business of home building while he/she inserts all the visual goodies. Win-win for everyone involved!!
continuous outer insulation on a red iron barn... what to use???
That is a tough one, all of the continuous insulation methods I am familiar with require mounting surfaces that are close to traditional framing methods. You would need substrates like that of traditional framing to attach insulation.
Ford F series.
Do you have any insight on Zip Rs cold weather performance being polyiso? I’m at 8000’ in Colorado where it goes below zero almost every night for a few months and I haven’t been able to find any documentation on zip r’s specific performance in cold weather. I’ve debated just going to a 2x8 wall.
Also any thoughts on the typical Kraft faced insulation compared to the smart vapor barriers? Especially in my super dry 6b climate I can’t image much vapor diffusion happening if I have a very well sealed container exterior air barrier with the zip.
I’m in the same situation, 8600 park county. I’ve read zip r with wrb outside and continuous insulation behind that can lead to some condensation issues. I want to find some framers who’ve worked with stuff before. We are acting as our own GC, but all the experience husband and our architect have is not in our county and does not normally need continuous. So I am very curious on his opinion and your details too.
ZIP R is not vapor open and is therefore better avoided... unless you add enough - twice the R-value of the ZIP R sheet - extra insulation outboard (exterior).
But to get rid of your moisture in winter time, you'll need to ventilate (which is not a big problem these days for new homes with an ERV).
zip r isn't exterior insulation. jake signs checks from huber who makes insulation in-board of sheathing. great product and nothing wrong with getting paid, just not apples to apples to actual exterior insulation. similar but not the same.
@@stevecrawford6958 OK, the main question becomes then: where to add the extra insulation in case of cold winters, on the inside or on the outside?
Second question, what about the seams of the ZIP R-sheathing? These are not insulated and 100% vapor tight (ZIP tape)... In case of condensation, the OSB of the ZIP R-sheets become wet and you don't want that...
@@stevecrawford6958 The Zip-R insulation IS exterior of the framing. But IMO its two problems are lowered shear strength, and probably the bigger problem is that with it, you now have a framed wall assembly with vapor barriers on both sides. The foam of the Zip-R is effectively an added/unwanted vapor barrier.
As someone who has repaired my share of water damage over the years, i have a really hard time getting onboard with any system that puts insulation outside of the house sheeting.
I felt that way to begin with to start with too. However detail is not terribly difficult and it can be done.
@@jake.bruton.aarow.building We're just down the road from you guys, well, figuratively. When we built our own house in 2020 we went with 2x6 advanced framing with insulated headers. We tried to size and space windows and doors to eliminate unnecessary studs and cripples. Used Zip, and was very conscientious about air sealing and taping. Wound up special ordering full width tapes for window and door openings that nobody local carried. Did a full foamed envelope and so far are very happy with the way it turned out. Is it the best system? probably not. But it was a fairly economical system that wasn't hard to execute by someone with good Carpentry skills.
I had just finished up a repair job where water had gotten behind 1/4" foam board under siding around replacement window flashing, and, oh boy, some of it was bad enough we wound up replacing studs and doing some mold remediation. Bad deal. Every detail has to be correct. These were tiny leaks around corner trim on replacement windows that didn't dry over time and caused a disaster. After the repairs, that house got fluid applied flashing, fluid applied barrier, and all new windows. It should be good now.
Videos at least for sound quality, in the truck are better than job site videos with all the echo off the walls. Makes sense as quiet driving experience is an automotive key requirement.
Wouldn't it stand to reason that exterior insulated sheathing like Zip R would compromise the structural integrity of the walls? The framing provides the resistance to vertical forces,, while the sheathing provides resistance to lateral forces. It takes the 2, together, to bond the structure. Traditionally the sheathing is bonded directly to the framing, resulting in a single cohesive timber structure. When you add something like an insulated backed sheathing, now the sheathing is not directly connected to the framing. The sheathing now has a stand off the thickness of the foam insulation, which obviously does not have the strength of the wood products, and now all of those lateral stresses are being directed into the fasteners that have a significant gap of foam between the sheathing and the actual studs that they mount to. There is no way that those fasteners are designed to take that kind of lateral forces when they are standing off the framing by an inch or more! I understand the rock wool "blanket" appears to be more of an insulated wrap over traditional structure, but the Zip R solution with the foam on the INTERIOR side seems extremely worrisome to me from a structure prospective.
The thicker the poly iso layer, the more reduction in shear strength, that's correct.
But If this reduced shear strength is an issue or not depends on your location and design, Huber Wood has a table about this.
Shear resistance probably has more to do with size of panel, height of wall, and location in the wall......
Zip R is used in western Oregon and Washington where seismic and wind load requirements are quite high. It’s all about the size, spacing, and type of fasteners. That said, it can very handy to use conventional sheathing (whether OSB or plywood) so you can use standard prescriptive fastener tables in the code, not worry as much about over-driven fasteners affecting the adhered WRB on the Zip, and then cover all your penetrations and required strapping with a fully adhered WRB and one or two layers of exterior insulation. Just depends on what you’re trying to accomplish and how you want to accomplish it based on the skills, expertise, and comfort level of the contractor(s) and crew.
@@MichaelJ674 That's basically the conclusion that I was coming to myself. Zip R seems to be much more focused on ease of installation for the contractors, at the cost of an inferior end product for the ultimate customer, as opposed to the other methods employed such as traditional sheathing with rockwool or insulating agent on the OUTSIDE of the sheathing, which would give you the best of both worlds. Traditional sheathing strength with added benefit of unbroken insulation layer exterior of the sheathing and studs. It sounds like everyone is confirming my suspicions, while saying that, yes structural integrity is reduced, yet still "safe" and within "code". I personally don't like that answer very much.
@@koenraadprincen7212 That was my fear. While I understand logically that something can be absolutely measurable, while at the same time statistically irrelevant, The idea just doesn't sit right with me. A better product should be better on all fronts. Maybe traditional sheathing is rated for 200mph, and the Zip reduces it to 180? Both are far and above any normal wind burst, yet both are far below any moderate tornado. Both would fare essentially the same in either conditions, so does it really matter? IDK, I just don't like the idea of it and maybe that's not logical on my part...
10:42 The rule of thumb is actually max. 30% *inboard* (and 70% outboard).
In general it's better to use vapor open and moisture (wetness) tolerant materials in your walls (and to avoid plactic insulation material like EPS, XPS, Poly iso,...).
Climate Zone 5 = 30% (Exterior) Climate Zone 6 = 35% (Exterior) Climate Zone 7 = 45% (Exterior)
@@rangelinehomes Not good... and what would you recommend as extra internal insulation material?
@@koenraadprincen7212 It’s a percentage so do the math to get whatever total insulation target you’re trying to achieve whether that be code minimum, passive house standards, or something else. Typically, that will vary by climate zone. The easiest formula is to fill your stud space with whatever kind of insulation you prefer and then add enough continuous exterior insulation to meet the percentages listed above.
@@MichaelJ674 Well, there is a difference if you're using vapor open or vapor closed insulation.
Together with the amount of relative humidity you like for your living comfort.
In general, it's best to place all the insulation at the outside (cold side) of your air (and vapor) barrier.
If you're using a wool like insulation material like Rockwool, TimberHP, sheep wool, fiber glass, etc... it's even better to use two air barriers, one on each side of the insulation layer.
Both air barriers must be vapor open, while the one on the warm side may be a bit lesser vapor open than the one on the cold side.
When you're using vapor closed or vapor retarding insulation material like EPS, XPS, poly iso, closed cell spray foam,... you can do what you like (altough it's advisable to tape all the seams on both sides or at least on the warm side).
Lots of what's told about Building Science on these different RUclips-channels comes from Joe Lstiburek and his concept of "The perfect Wall", but many people forget that his perfect wall in his lectures are based upon EPS/XPS insulation foam which is vapor retarding and can resist moisture.
What works for one insulation material doesn't work for any other material.
Ha- I hear ya, Jake. Columbia weather can be brisk! 🙂 #mizzou
Are you both SERIOUS? In '78 I walked to school both ways, uphill, and barefoot
It's such a shame that Rockwool is so expensive. It's brilliant stuff and I'd much rather use that than foam. But it just doesn't fit the budget.
And what about TimberHP (wood fibre)?
Ford truck. The front windows dip down as it goes toward the front. Obvious giveaway.
Likely Zip R because one trip around the house as per usual
It's a solid system and we are seeing more contractors moving to this method.
@ like you always say. Key word is system. Builders need to take advantage of the technology available to us.
ZIP R is not vapor open and is therefore better avoided... unless you add enough - twice the R-value of the ZIP R sheet - extra insulation *outboard* (exterior).
To get rid of your moisture in winter time, you'll need to ventilate (which is not a big problem these days for new homes with an ERV).
@@koenraadprincen7212 I not certain where you are coming by your information but depending on your climate zone some places in the code actually require a vapor closed assembly. Further more a vapor barrier at some point in the wall isn’t really of any concern to me as the builder so long as we preserve drying potential in both directions from that impermeable layer. Zip doesn’t make a product approved for the very cold climates (according to code levels of insulation) and I probably would recommend using it above say climate zone 6 because of this. There are other methods that would work for less money and effort at that point. But the idea that something is vapor closed and therefore should be avoided isn’t correct so long as it is known that it is vapor closed.
Well said Jake
Ford F-series SuperCrew.
Got to get away from foam.
Yes, there are much better options these days like Rockwool, TimberHP, flax, hemp, cork,... that will also help against overheating in the summer and that have better sound proofing qualities.
@@koenraadprincen7212 I don't deny the premiss, but all those you just listed come with serious challenges
@@stevenbaczekarchitect9431 Not if you build the European way, that's:
- Air barrier and vapor retarder on the warm side (that's inside when you have cold winters).
- Insulation material (if possible with "moisture buffering properties").
- External sheathing that acts as an air barrier and that's more vapor open then the vapor retarder on the inside.
- Additional vapor open insulation if needed.
- If that additional insulation layer is not wind tight, add a vapor open facade foil. For example, an exterior grade wooden insulating fibre board like Gutex, Celit3D/4D,... is considered wind tight if you use the T&G sheets.
- Air cavity.
- Cladding or veneer (or even stucco with some changes).
Done 🙂
In a hot and humid climate, you can make the outer air barrier more vapor retarding than the inner one, that's it.
And that's problem with ZIP R-sheathing, it does not fit into the European style of building, regular ZIP can be used, if not too thick.
In a hot or humid climate, ZIP (R) is better suited.
But in climate zone 4, I would not use it as the winters are cold.
In general:
- In a *hot and humid climate* , your main air barrier and vapor retarder *can* be on the *outside* .
- With *cold winters* , the main air barrier and vapor retarder *should* be on the *inside* .
@@koenraadprincen7212 OK, I will give it a try here.....why would I build the Euro way? I'm not it Euro. Do you know why they do what they do? Mainly because their base frame is masonry, not a wood frame. I have been to Europe a number of times and actually heading there real soon. I am very familiar with what they do, and why they do it. Why do you think it's better? I HATE the air barrier on the interior, makes no sense to me. The best air barrier in my opinion is a straight line. Displacing that line causes problems and headaches. In my early days we did ADA on the interior, and it was a pain compared to outside now. Why do really care? If I take a house to sub .60 Ach50 Pa there's no air moving across the wall, even with the AB on the exterior. The moisture buffering properties, yeah they may exist, but I don't think its at levels that will save a wall. So whats your external sheathing that is more open than my Siga Mayrex? Maybe exterior Gyp Bd - no thanks. Exterior insulation if needed ? When do you consider it needed? I think always?? Gutex or wood fibre? How are you economically attaching that? How are you trimming out those windows? How do the windows connect to your interior Air Barrier? I know these answers because I have done them and are doing them. It is not easy, It is not cheap, It is not common - it is a challenge. Air cavity - agree 3/4"......As for Zip, it isn't sold in Euro, so good thing.
I'm not trying to be a jerk here, I actually agree we build crap in this country for the most part - commonly it is a very low standard to what we know. Building perfect Building Science is costly, for some hard to understand, and execute. There needs to be a "sweet spot" found, to which I search for on every project......
I would say I have been around the block, actually more like around the country.....I'm not bragging, just stating fact. I have designed some of the most efficient Building Science Friendly homes in the country. It's not easy, and I am always thinking - always!!! I appreciate your comments, really do, but I don't think you appreciate the challenges you have outlined above.
Lastly, many have been referencing other videos, and people - here's a thought for you, because I know most of them. You ever wonder why those that speak "perfect" Building Science make videos and talk about it? But they don't do it, they don't have their projects illustrating their ideas, they don't have test results from their projects. They don't have referenced conversations with contractors and such, because they don't build - Building Science is an Academic Exercise for them, and that's fine, but before they come to the table to talk about what to do, maybe they should "do" something.
Please do not take offense I am having a conversation with you, and being brutally honest with you, that's who I am. Like I said, for the most part I agree with you (except maybe the interior air barrier - just doesn't make sense). Now you got me fired up, it's 2am and I won't be able to fall asleep for a couple hours lol - thank you for joining in.
@@stevenbaczekarchitect9431
Sorry to have kept you awake ;-)
*About "Euro-style"*
Besides brick masonry, wooden framed houses have become quite popular in Western-Europe.
In my discussions I'm always comparing apples to apples, so Euro wooden framed houses vs North Americain (NA) wooden framed houses.
(As a side note: in Europe the walls of wooden framed houses are almost always prefabricated, framing on-site is rarely done).
In general, sprayed foam is in Europe almost never used to insulate walls or roofs (only for floors). And you won't see it used in wooden framed houses, as Europeans consider wooden houses as "healthy" (that is why natural building materials are popular for people building a wooden house in Europe).
*About Building Science (BS)*
The physics in BS is the same everywhere in the world. The differences are in the way they *can be* applied in practice, because as you know, the building trade is very conservative ("we have done it this way the last 30 years").
I've seen most - if not all - of the lectures of Joe Lstiburek on YT about his "perfect wall", I like his concept about the different control layers and - *as a concept* - his wall is indeed perfect. But you can not translate that concept "one on one" into the real world, a lot depends on the materials used and the interaction between the control layers. His concept works fine for EPS/XPS/Poly Iso/... but not for any vapor open insulation material, not to mention materials that are also not water resistant.
*Building Practice*
One of the main differences between Europe and NA, is that in Europe *most of the time* , the (OSB-) sheathing for the shear forces ("racking") is on the *inside* , that's the warm side in winter time. That way, the sheathing doubles up as an internal air and vapor barrier, just tape of or caulk the seams. So, two of Joe's control layers are on the inside.
Advantage: the insulation will be at the cold side of this sheathing, so there's no risk for condensation. (It's actually like flipping the ZIP R-sheathing to the inside).
Disadvantages:
a. You need a good quality of OSB as not every OSB is/was air tight.
b. You need an extra "technical cavity" (about 2") for electrical wiring and (small) plumbing (but this cavity can also be filled with some extra insulation).
c. Connection with the ceiling or floor beams of the second floor can be cumbersome (in order to keep the continuity). But this problem can be solved by using balloon framing.
For windows and doors, it doesn't make a big difference if your AB is on the in- or outside. At least, not when using European style windows. When using a typical flanged window, an external AB is easier to guarantee the continuity of all control layers (except thermal). I agree with you on that one.
European wooden framed walls always get - at the outside - a *VAPOR OPEN* facade foil or a vapor open (insulating wood) panel (like Gutex, Celit 3D or 4D,... or TimberHP in the USA). *This exterior foil or insulation must be able to act as a water control layer* .
We always make sure that our wooden framed walls (and roofs) are vapor open to both the in- and outside. This is the reason why ZIP R-sheathing won't have a chance in Europe as it's to be considered vapor closed.
*Getting the best of both continents*
I think we both can learn form eachother... The ideal solution is quite easy...
The regular ZIP panels - those without the poly iso layer - have their advantages:
a. They are guaranteed to be air tight due to the WRB layer (green/brown), which is/was not always the case with regular OSB.
b. They are vapor retarding.
c. They can be used as weather protection.
In Europe, this would be the perfect air barrier...and maybe that's the way we should look at it, let's put our AB to the outside as in NA but apply the European insulation logic to it. As you said, external continuous insulation (CI) is always a bonus. (It's even mandatory in some states).
So this leads to...
*The perfect wall for NA and Europe*
- Frame the walls as usual, but take the minimal size (as needed per code or as stated by the architect/engineer for stability reasons).
- Apply external structural sheathing and treat this as your air barrier and vapor retarder. Regular ZIP panels are a good choice.
- Apply a *VAPOR OPEN* *external insulation* (thickness as needed per code or as wished).
- Apply some additional insulation between the studs but with a R-value of max. 50% of the R-value of the external insulation. *If you keep the inner R-value below 30% of the outer Rvalue, NO extra AB or vapor retarder on the inside is needed (in CZ-4)* and you can choose a material rather for their properties regarding moisture buffering, sound proofing, air quality, thermal inertia,... so good candidates are sheep wool, wood fibre, flax, cellulose, cotton,...
- Finish the inside as usual (sheetrock).
- Finish the outside as needed by the manufacturer of the insulation material (i.e. facade foil as water control layer) and as needed for the final cladding or veneer.
- Done
In short, do as Jake is telling in this video but use regular ZIP i.o. ZIP -R-sheathing (unless you're building in CZ 1 to 3).
Ford F-150
F-250 actually. Too many trailers.
Ford