East CAanda here following your series and binge watching during a very Canadian cold spell Winter. Educational so far. I need this to prep for a few renovations and an extension. Was planning on the 2.5 high story gambrel roof to have exterior insulation, as you pointed out in #1. This is so interesting. Thank you.🙏 🇨🇦🍁 I am a Matt Risinger and Steve Bascuk follower and a Joe Lstiburek follower as well.☺👍
Super informative to me as a consumer. I wish I would have had this information when we did a well insulated addition onto a 100+ year old home. Did the bat insulation in the ceiling and the short wall of the room inside. Later had to blow in additional insulation because of condensation issues. Have added power venting in unconditioned area to deal with hot summer temperatures in the bedroom. Getting this information makes me want to tear out and remove all the items needed and having closecell foam installed. Sometimes that room is more uncomfortable than the 100+ year old house upstairs is and it doesn't even have good insulation.
I’m just here to research before building a tiny home on land. Plan currently is 12’X20’ on piers. 3-4x12 pitch with 2” rigid under a standing seam over osb all on top of 2”X8” rafters with 4” of spray foam then the ceiling nailed to the underside of the rafters. At least that’s the plan.
Nice presentation! 👍 I think you pretty well covered everything pertinent in this segment. I appreciate you taking the time to present this information. I was a die hard "flash & batt" guy and the information you have presented in the last several video's has changed my mind. I totally agree. I'll be going with closed cell spray foam. The only exception will be interior wall sound proofing with Rock Wool. Glad I have been following along with your video presentations. They are WELL worth the time invested. Excellent job!
I was never truly on board with flash and batt (mainly because it would’ve been me doing the batt for the entire cathedral roof and walls), but now I have an understanding of why not to go through that trouble.
Major definitive work. Next vid will take us to the outside air and that is the game changer. Liquid applied, peal and stick, CDX or OSB, Zip or not, regular underlayment with shingles, cold roof with steel, added rockwool over the OWB/water proofing or not, and oh boy will this be good. How great would it be if we could use CCSF on the top of the sheathing and on the outside of the wall sheathing for full envelope water/air/vapor including the underfloor!!!! Thanks thanks thanks. Bob Jarrard (50+ yrs as a general contractor and glad I only built in very temperate climates)
Thanks for all of your work and details!!! I know spray foam is more expensive initially, but over the long run it’s “less expensive” in total cost (ie less energy costs, minimal maintenance, get rid of the moisture inside attic, etc., etc.). I have a buddy who only looks at $$$ out of his pocket at any given moment and does NO preventive maintenance and/or looking at the big picture (ie spend more now to spend much less in the future). He has a few rental properties and is now facing extensive repairs / replacement of things like total tear down of roofs, replacing soffits, re-insulation of attics, replacing windows & doors because of dry rotting, etc.!!! I’ve been telling him for years “you need to keep up with maintenance and remodeling ... now he is realizing just how much all these repairs are going to cost ... sad thing is it was all preventable (the extensive repairs).
Excellent education 👍. I will have to study my plans to make sure my builder and spray foam Guy get everything right. The builder I'm thinking about using for my house in FL has his own spray foam company that he started year ago because he was having issues with quality spray foam contractors. He was doing air door testing before it was required so I feel like he will get it right but I still like to have the education and knowledge myself. Thanks 👍
Exactly right. Absolutely brilliant, closed cell on underside of roof deck is the way to go. So I guess you would ho for r32 or 5 inches of closed cell? All this stuff gives structural advantages, keeps entire truss warm, you get extra storage and you don't have to worry about water leaks in your home Boom. Well done.
Thank you...bought a 150 yr old fixer -upper. People keep telling me I need roof vents and soffits? Attic looks great and have new metal roof. I figure if it lasted this long it obviously doesn't need roof vents! 😉
Only problem I see is if you needed to replace the roof sheeting with the spray foam glued to it. I would agree spray foam would make the roof stronger. I've used 2 inch foam board over the roof sheeting. Then used 2 x 4 going perpendicular to the rafters for roof sheeting or metal roofing. I tape all seems for airtightness. Then use rockwool between the rafters. The whole building is wrapped outside in 2 inches of foam board. My way is probably more complicated and costly.
Excellent informative video. We have recently had a cabin in Wyoming we are building spray foamed with closed cell. What started as a vented metal roof ( vented roof peak and soffit ) changed to a closed cell encapsulated roof. My concern is on the blocking at the soffit between 2”x12” rafters . It was blocked with the original intention of letting air in thru the soffit by way of an air gap over the top of the blocking. When they sprayed foamed that area they covered the entire area around the blocking in foam so it is sealed. What they didn’t do was block off the open area above the existing blocking, approximately 1” to 2” with wood. Should it have been or is the foam filling that open space effective? The other concern is the vented roof. Again it was sprayed foamed and sealed but not blocked off with blocking Thanks for taking the time to get this information out there. A great resource for anyone considering closed cell spray foam Insulation.
1. For starters that must have made a huge mess. We use at the least cardboard to prevent the foam from puking out the vents and making huge messes. They should have talked with you about that.... 2. Foam should have a backer so that it is stronger. We don't like to bridge open gaps any larger than 3/4". Hard to say what will happen. I have seen weak connections in time let go... but if there is 3 or 4 inches of foam over a 1.5" gap it can be Ok for a lifetime; It depends on building movement.
Great job explaining everything have learned a lot from your videos will keep watching them. Going to build a house in Pennsylvania wish you guys could do the the spray foam job.
I appreciate that you provided the reference to a lot of papers. however, there was no mentioning who sponsored the research. The research which had clear sponsorship was from spray foam association. Cigarette industry sponsored a lot of research papers back in 50s to show cigarettes were beneficial.
Curious what your thoughts are on AeroBarrier and whether it should be utilized before/after SPF, especially considering using it on a house with a conditioned attic space.
The idea is sound. I think there is no replacement for hand applied caulking and going over ever ft2 yourself to ensure the seams are for sure done well. We have a 2nd person doing it while cleaning up is underway.
I think you had mentioned that the R-value requirement is less when ccSPF is used. I will be building a post frame designed by Paul Marshall (Mr. Post Frame), in North Idaho, Zone 6. The main living area of the home will have cathedral ceiling. R-value requirement is R-49. Do I have to get to that R-49 with ccSPF? Are the requirements less in this application? Can I do a certain amount of ccSPF and then the rest with a bat product?
Question? We have a Viceroy cottage in Northern Ontario with a wry low slope cathedral ceiling composed of 4 inch thick tongue and groove panabode roof deck which has sheathed on top of with plywood, ice and water shield and new fibreglass shingles. Being that the TNG ceiling is completely exposed cedar would this be an appropriate application for closed cell spray foam to turn our 3 season cottage into a 4 season home? The structural members that hold up the panabode roof deck are 4x12 cedar beams approximately 5 feet apart.
My attic doesn’t have baffles, only gable end vents. Those octagonal shaped ones. As a result there’s white mildew (or mold) on about 2/3 of the plywood underside. If the plywood is sound, could I have it spray foamed right over the mildew? That will encase it, but I guess it would have to be done after drier weather.
Wish I had saw this before adding vents to my previously non vented conditioned attic. Turned out my problem was 1/4 inch R-1 polyiso used as the only insulation in some parts. Eventual plan is to gut the attic and spray foam it all. Dammit!
Thank you for your great clarity! I have an all steel building with 2 roof supporting trusses that are 100٪ steel. On top of that running the length of the 60' building are 6" steel purlins Of course they touch and support the all metal roof. My question: I believe the perlins need closed cell foam. But do the the 2 supporting steel trusses need spray foam?? As they only touch the bottom of the 6" steel perlins?? You are the person who can help me do the job right Thanks for your great videos ! just jim
The perlins do, after they have been insulated most connecting structure is secure and inside of a warm space and require no insulation. Keep in mind I am not looking at you job...
@16.30 mark. If one is worried about the cost, they should compare the cost of the spray foam to the cost of going back years later.... with ...inflation.... and compare the cost of replacing their roof, joist, insulation, and possibly sheetrock due to where damage. It far far cheaper to do things right the first time than to half ass something that is built to protect your family from the elements.
21:00 You say this can be used as storage. It can be but the ceiling joisting has to be engineered for a storage load. Like 2x8 in place of 2x6 where you plan to lay the planking. I know you said that you simply do not call it out, but if the bottom chord is a 2x4, you will get deflection if you later put in a walkway or storage floor for heavy loading. Also, as of 2020 and later, if you DO use the attic for storage or access of some kind, the underside of the foam MUST be protected from fire. This is done with fire paint or sheetrock or other fire resistant material. The underside of the foam does not need to be protected if you do not use it for storage or other kind of accessible space, like HVAC installation space.
@@SprayJones Sir!! You do a fine job and I have learned an enormous amount from your vids. My knowledge comes from inspection failures and some ancillary research. Plus, I had to make a code-compliance case with citations for my cabin at 7500' feet altitude - climate zone 5b: cold/dry - for the Clark County/Las Vegas building department down in climate zone 3. Seems my plan checker, a woman from Bombay India with an ESL degree from a junior college kept failing the plan specs for my unvented cathedral ceiling like you show here. My concession to her was not using the attic for anything but ductwork and plumbing vents. Which I wasn't anyway because we have a basement, rare in Las Vegas area.
First, I really appreciate the videos as I am planning on building my home. Long time follower. One question I have watching this detail is, should I use vented soffits? If the rafters are blocked and then spray foamed, I would assume this would be a capillary break, but should the soffits still be vented in order to have air movement to prevent moisture buildup in that area? I want to insulate once, and prevent any damage that I can to the highest extent possible.
Many do not use vented soffits. I had one that did very nice trim around the perimeter instead. Looked awesome. 98% stay with vented soffit because that is in bulk at the supply warehouse.
If you spray foam the rafter of the attic, remove insulation between house and attic, then all conditioned air will flow into the attic. What happens when warm moist air hits a cold attic ceiling in the winter and when cold indoor air hits a hot degree attic ceiling in the summer?
Thanks for the enormous content. I have a situation where a cold room is against a neighbouring shop and the wall is sweating. Would spray foam or conventional insulation stop that problem? Any ideas would be greatly appreciated. Regards, Matt.
Why are you not spraying all of the way out to the Facia? In cold snowy areas an ice dam will form where cold the outside air acceses the sheathing at the wall line. Thanks for the rest of the info.
Awesome video! I live in Southern California, house was built in 2000 and has a vented cathedralized attic and my ac/heat unit lives up there. Summers easily reach 100°F plus. Would it be a bad idea to spray foam the underside of the sheathing if it’s going to remain vented or should I cover up that vent?
At 17:26 you talk about covering the steel nail plate’s, with longer nail plates for attic trusses do you still need to cover the whole thing? Approximately 12” to 16” long
If it was going to be living space this is still the way to go correct? I have engendered truss cathedral ceiling with a vault in the middle and dormers. It’s so cut up I can’t think of a better way to go. Thanks
Great video Mike! I only recently became aware of your channel through the Marshal project, but so glad I did! I have been watching a lot of your older videos to catch up. Do skylights change the calculations at all? Specifically, I feel that skylights are prone to water leaks over time, and with closed cell keeping water in place, wouldn't that amplify the damage to roof sheathing? Do you do anything different at skylights?
We spray them in around the boxes. Skylights always leak... so it is like a boat: the day you like it the most is on the first day you get it, and the day you get rid of them.
@@SprayJones That's so true! I look at the 3 skylights I have at least once a week trying figure out if they are leaking yet. I plan to spray foam the vaulted ceiling they are installed in, maybe they'll get removed then. Thank you
Thank you for the very detailed video and examples. I have a roof constructed of roof trusses which are 2x6 for rafter sections. As closed cell foam is approx R7 per inch and I need to achieve R38 or more for NYS code, is the only and best solution in your view to "pony up" and do almost 6 inches of closed cell? Alternatively, do you see any value to some combination of spray on underside and either rigid foam sheets on out side or batts inside ? Again, great content - thanks for taking the time to show your knowledge and be a good advert for the industry.
@@SprayJones Thank you for the reply and for the great content on this channel. You should consider a consulting business ! Keep the good info coming....
I am going to have my new home spray foam with the underside of the roof as well if my building inspector will go for it here in Milford PA any tips to help the building inspector agree to it. This is great keep it coming. Thankyou.
I have a 117 year old Dutch colonial farmhouse with a gambrel roof constructed from 8x8 timber. The second floor is in the roof so it’s an occupied space. Currently the only insulation is 4 inches of fiberglass batting. Obviously this is laughable. Is closed cell spray foam good for this application ?
great information on all your videos......im a farmer from South Dakota and i bought my own spray foam machine to spray my steel shop and ie done that as well as doing a few other projects for neighbors. the machine i have is "the lil pup" from myxsyn. Its a very interesting machine and works great. Anyway im building a shouse this summer and will have a 48x48 living space and 60x60 shop. 20ft sidewalls and having standard trusses with a 4/12 pitch. thinking spraying the steel (tin) on the entire building roof and walls and going to have radiant infloor heat. is this something you reccommend? looking not to have to spend money on sheeting the living portion of the house .... thnaks again man
Greetings from Ottawa Canada! My house is a mid 50s bungalow, with the attic insulated with R25 blown in fibreglass. All of the soffits are unobstructed, very good ventilation in the attic space without ice damming or frost / condensation issues. While getting quotes to upgrade the insulation, one company recommended removing all existing insulation, spray foam the attic floor where the existing insulation is, and top up with blown in for a R60 value. Having watched most of your videos I already suspect what your response will be. With that, what are your thoughts on the proposed solution, just spray foam insulting the attic floor and leave the attic ventilated, or close all existing soffit vents, remove the roof vents and coat the underside of the roofing with spray? I'm trying to take advantage of the current government energy rebates for insulation, which of course are all tied to achieving a minimum "R" rating. Having watched your videos and learning of the truth of the R rating, it is really frustrating knowing spray foam is so much more effective, but doesn't meet the requirements for attic rebates. Hopefully the tail catches up with the dog. Thanks for your excellent and informative videos!
I say it depends on the pitch and size of the house. I’ve never done one where the customer blew a fibrous insulation per the foam. And I’ve only done less than a handful of spray down jobs in 12 years. I would never recommend it or hope to do another. I’ve done some renovations where we sucked all the insulation out and sprayed the underside of the roof. The customers absolutely love these.
So, when I win the Lotto Max and build my "Forever Home" in New Brunswick, do you have a list of reputable spray companies in my area or a way to find these people? Anyway, my eyes have been opened and I'm very impressed with your content. :-)
I do not know contractors out there. You can contact BASF if you like in TO and they will let you know who they sell to in your area. Otherwise you vet the locals based on the principals I have given..
This summer I had my home, a relative new build 2015 here in Texas, retrofitted with spray foam in the attic. One thing the company did was removed all ceiling insulation, I am aware that is typical. My TWO questions which I can not get any straight answers are; 1 should I go through and seal all penetrations from the living space into the attic to help slow down any excess humidity in the home, during cooking or showering for example or NO? Which brings me to note, that my kitchen does not have any true ventilation, just a microwave fan, hmm. 2, it seems as though voices/noise can now carry across room to room much easier now, suggestions? Thanks
The insulation not on the ceiling is normal. The trade off is that the sound can migrate through to other rooms. If you want to use batts for sound that is fine. Humidity in the home will not rise into the attic. That air is heavy and will stay lower in the building where it is circulated back to the HVAC.
I was hoping you'd address what to do when an atmospheric combustion furnace is in the attic. The attic must be vented for the atmospheric combustion furnace to have enough air to prevent it from producing carbon monoxide. How can we use spray foam in the attic if we can't spray it down on the drywall AND due to the furnace we can't close off the vents in the attic? This is my situation now. I'm in the middle of my remodel and my new atmospheric combustion furnace is installed, and I didn't know what I didn't know (that I should've installed a sealed combustion furnace). What can I do assuming ripping out the furnace and replacing it is not an option?
Thanks for the response. I was just worried about possible moisture in between the metal and the foam board. Obviously there would be an air gap. Any thoughts?
You do a great job of selling closed cell foam on the underside of the roof but you don’t address the issue of moisture within the conditioned space. The AC system is inadequate to remove high levels of humidity within the conditioned space largely in the south eastern parts of the US that have high humidity during the summer months. Whole house dehumidifiers along with ERV/HRV are necessary the tighter a home is built.
Hi Mike, quick question: I'm doing closed cell foam under the roof sheathing, (completing and sealing the insulated envelope: slab/walls/roof) then the sheathing, Ice and Water Shield or similar, a slip sheet, and a standing seam metal roof. Is there any moisture between the metal and the membrane that needs to escape (if installed dry)? Do I have this right, you're recommending an unvented ridge? Please confirm. Thanks.
That is a question for your roofer, because it involves external moisture collection and disbursement. From the inside as long as the foam is installed correctly there is not going to be moisture issues.
Do you have any info on spraying foam onto exterior walls from the outside? Unfortunately have to re-side and have a plaster interior and though it might be a good opportunity to re-insulate on old house.
Mike, I am in a situation with the HOA owns the roof. So I can't spray the roof. The trusses/chords are all 2x4. I am having the cellulose removed to facilitate the electrical and venting clean ups. Would like spray foam installed but they want to spray the underside of the roof and the "decking" (top of ceiling-drywall) with closed cell. $$$$ What to do?
I don't have enough understanding of your situation to say. If you have enough room to spray down safely then go that way. If not, skip using SPF. Make it right or not at all...
@@SprayJones From researching it more. I am in IN..Zone 5. So can't spray on the underside of roof (HOA). I can spray on top of the ceiling(drywall-"rafters"). So I can make a vented system. I think in this case open cell on 2x4's. Can I then put plywood 1/2" over the foam. Not for living space, but for storage space.? Thx
Watching your videos has answered a multitude of questions I had about spray foam. I initially considered a diy since I'm doing all other aspects of construction myself but have more decided to get a professional spray job. My problem now is finding a contractor in my area (Central Pennsylvania)... Any tips?
Do you have any advice for someone considering metal roof trusses? With the rising cost of lumber it’s become a more enticing option. I am not sure if spray foam would be the way to best insulate them, or if exterior SIPs would be the best. Do you think encapsulating the entire metal truss would have any value or be feasible?
If you use metal truss you need exterior rigid or SPF from the inside to stop the metal from getting so cold and causing condensation issues in the attic. I have no issues spraying the top flange and embedding it in SPF.
Spray Jones thank you. That’s exactly what I was envisioning. With metal you should be able to mix both systems right? There isn’t really a chance for rot besides rusting over time.
Hello my question was how can you replace the sheathing if its rotten and still get a air tight seal i researched this and nothing,.. i guess you can replace the steathing and take the drywall off from the inside and spray the foam and replace the drywall? would this be the case?
the paragraph leading up to the 7 minute mark DEMANDS some interpretation, hieroglyphic comparison analysis, or SOMETHING - does anyone even glimpse what is being described?
Richard, Many people will place a sheet product over the truss top cords so that the interior surface of metal is not exposed. This means that the SPF will not be sprayed direct to the metal but the membrane instead. This can cause the SPF to pull down on a loose fitting sheet product which will form voids and gaps behind the metal that water can enter into from the outside and stay there.
Do you normally wait until things on the interior are ruined to find out you have a roof leak? Then replace the Sheetrock, insulation, and lumber? The foam will keep the leak at the roof.
Hate to beat a dead horse but what about all this talk of humidity problems and dehumidifier needed in the attic southern us states . Just dehumidifier and run ac duct up in attic, or that fake news
