I'm in the process of renovating and remodeling a very large (6000+ sq ft), 2-story antique house. Oldest portion built circa' 1900 with an addition put on in the 1940s. Originally was the 'main lodge' for a very expansive lakeside resort. The winters in NW WI get to -20 regularly and summers can see periods of 90+ fairly commonly too. (zip is 54817) The exterior siding is LP "smartside" (compressed wood) with solid vinyl trim everywhere - leyered over housewrap. The wrap was tape sealed. The windows are all new Andersen low-E doublehung (all 58 of them!) All windows are tape sealed for both air and water. Full basement - unfinished - but intending to finish for complete living space. Full attic (not walkup but accessible) of approx. 1000 sq. ft. I've got nearly all the walls 'open and empty' - ready for insulating. ---------------------- I'm thinking of spray foam for the air-sealing qualities, but I am also very interested in doing as much of this myself as possible. In my experience so far, a spray foam install does not appear to be a DIY job. Obviously I can do any batt installs that may be recommended, but I'm not sure on the layering that should be done. Any and all suggestions are greatly appreciated!

Take a look at my addition thread a few down.

http://www.greenbuildingtalk.com/Forums/tabid/53/aff/22/aft/82339/afv/topic/Default.aspx

I would think the thing wouldnt be too tight other than the siding and house wrap with settling and air tightness only now becoming popular. With my new construction I am doing an inch of foam and then going to pack the rest with cellulose. Would probably be a real easy way to tighten up the envelope in your structure if you are redoing the drywall or whatever wall is used inside of the structure. This type of foam that I used is supposed to be very low VOC if you are concerned about global warming potential. The stuff has been a blast so far to install. Very easy. I couldnt find many reviews on the stuff anywhere which is why I put up the youtube videos to help people out. The kit comes with everything you need except the air compressor. Dont skimp there. Buy the right size or rent a big one somewhere. I elected to purchase since the only place that could rent me one that had the minimum spec was a pull behind jackhammer type that was $150 a day to rent. After a week I would have paid as much to rent as to own. Plus I needed a good compressor anyway. I could have gotten a contractor to do the work but the quote was anywhere from $1.20 a board foot to $2.40 for just walls. This kit worked out to be something like $.70 a board foot and still cheaper than what I would have paid a contractor with the purchase of the air compressor. I also intend to buy an extra case of the stuff here and there when I remodel the kitchen and bathrooms to do the exterior walls. I have one bedroom that I need to redrywall as well as old paneling in the living room that I need to take down and replace with drywall. All perfect times to spray in 3 inches of foam at R6 per inch cured. The exisitng house is 2x4 construction with R11 batts with 3/4 foil faced polyiso sheathing. This would make a spray foamed wall around R24 when redone.

Posted By kogashuko on 12 Apr 2014 07:32 PM
Take a look at my addition thread a few down.

http://www.greenbuildingtalk.com/Forums/tabid/53/aff/22/aft/82339/afv/topic/Default.aspx

I would think the thing wouldnt be too tight other than the siding and house wrap with settling and air tightness only now becoming popular. With my new construction I am doing an inch of foam and then going to pack the rest with cellulose. Would probably be a real easy way to tighten up the envelope in your structure if you are redoing the drywall or whatever wall is used inside of the structure. This type of foam that I used is supposed to be very low VOC if you are concerned about global warming potential. The stuff has been a blast so far to install. Very easy. I couldnt find many reviews on the stuff anywhere which is why I put up the youtube videos to help people out. The kit comes with everything you need except the air compressor. Dont skimp there. Buy the right size or rent a big one somewhere. I elected to purchase since the only place that could rent me one that had the minimum spec was a pull behind jackhammer type that was $150 a day to rent. After a week I would have paid as much to rent as to own. Plus I needed a good compressor anyway. I could have gotten a contractor to do the work but the quote was anywhere from $1.20 a board foot to $2.40 for just walls. This kit worked out to be something like $.70 a board foot and still cheaper than what I would have paid a contractor with the purchase of the air compressor. I also intend to buy an extra case of the stuff here and there when I remodel the kitchen and bathrooms to do the exterior walls. I have one bedroom that I need to redrywall as well as old paneling in the living room that I need to take down and replace with drywall. All perfect times to spray in 3 inches of foam at R6 per inch cured. The exisitng house is 2x4 construction with R11 batts with 3/4 foil faced polyiso sheathing. This would make a spray foamed wall around R24 when redone.

Thanks for the reply! I have also looked at those spray foam kits (sans compressor). I have a couple good sized units now for running multiple air tools and the specs I've looked at would indicate they're both suitable. If I go that route - 1" spray foam behind packed cellulose - what did you use as a barrier on the interior side of the wall? I will be using a variety of interior wall coverings ranging from drywall to old barn boards to tile-over-cement-board. I would prefer to install any insulation I use before putting up any wall covering, of course. Does the temporary insulation install-sheeting to keep the insulation in place (plastic, tyvek, screening) work as a barrier? Any ideas for the attic space? The ceiling joists are just 2 x 4s. It will be vented on the gable ends and with 'pill boxes' near the ridge. The roof itself is only 6 years old and in good shape for now, but eventually will be replaced with steel and ridge-vented. No option for fascia-area venting as the upper level rooms all have 5' side walls topped with sloped 'roof area' ceilings. Those areas will have to be insulated like the walls. Again, any help or ideas would be greatly appreciated!

Have not finished mine yet but shouldnt need an air barrier on the inner wall. I am considering putting in OSB on the interior wall and then doing drywall over that to make it easier to hang stuff on the wall later. I certainly could tape that. There is also the net and blow option but from what I have read the DIY option for that takes a lot of work to fit the drywall after. You could also certainly go with the open cell spray foam kit for the same price and it would probably fill the entire cavity instead of just an inch but I would do the math first. You could still do fiberglass batts or rockwool over the inch of closed cell too. With the air sealing both would be much more efficient then without the foam.

As for the attic I intend to go 1 inch foam and then look at another way to affix more insulation under it. Net and blow would work great and I wouldnt have to worry about drywall. I could also leave it bare and just get some open cell kits every so often and blow more in. I certainly will not have to insulate the ceiling of the room under the insulated roof but I will probably do some R13 batts just because I will be using a minisplit and it would be nice to slow the heat flow into the attic a bit. It will make it there anyway but technically it would add another R13 to whatever is on the roof deck even though it isnt code. As for my existing house it is built with 2x8s under the roof. I could easily just put in some R30 batts under the inch of foam. Cheap and easy extra R value.

I wish I could afford to do the whole thing in closed cell or even an inch of closed cell and several more open cell. Bottom like with even the open cell kit I would have to spend another $3000 for enough insulation. The total cost I have estimated for cellulos will be about $400. About twice that if I decide to do under the roof deck but still cheaper. I see little issue with the stuff not being a complete air barrier with an inch of foam sealing everything.

Remember though with the air compressor that it is absolutely critical to get 10cfm @ 100psi for about 45 seconds. So test it once you get your fast kick gun like the DVD says. I found a horror story online of a guy that tried to rent a compressor that was broken and he never tested it before trying to spray. He also tried to hook two compressors together to make it work as well as using a 1/4inch air hose and a garden hose. As I was reading all of the stuff he tried I had to wonder what he was thinking if he was thinking at all before he did it. So dont do any of that crazy stuff just test your compressor and if you need a longer hose you can buy a 100 foot 3/8 inch house at lowes for about $30. It has 1/4inch fittings but will work fine. Just test test test the setup before attempting to spray.

Did another wall today. I think I have a system down now. Do the edges of the cavity first then spray and fill in.

http://youtu.be/wnQrlC0XGLQ

Posted By minwiswip on 13 Apr 2014 09:52 AM


Thanks for the reply! I have also looked at those spray foam kits (sans compressor). I have a couple good sized units now for running multiple air tools and the specs I've looked at would indicate they're both suitable. If I go that route - 1" spray foam behind packed cellulose - what did you use as a barrier on the interior side of the wall? I will be using a variety of interior wall coverings ranging from drywall to old barn boards to tile-over-cement-board. I would prefer to install any insulation I use before putting up any wall covering, of course. Does the temporary insulation install-sheeting to keep the insulation in place (plastic, tyvek, screening) work as a barrier? Any ideas for the attic space? The ceiling joists are just 2 x 4s. It will be vented on the gable ends and with 'pill boxes' near the ridge. The roof itself is only 6 years old and in good shape for now, but eventually will be replaced with steel and ridge-vented. No option for fascia-area venting as the upper level rooms all have 5' side walls topped with sloped 'roof area' ceilings. Those areas will have to be insulated like the walls. Again, any help or ideas would be greatly appreciated!

With an an air-imermeable inch (R6) of closed cell foam on the exterior of a 2x4 cavity, and cellulose on the interior side you're looking at R9- R11 of fiber, which is a ratio sufficient to be able to use a class-III vapor retarder  (latex paint is OK) on the interior side even for climate zone 7. (Birchwood WI is on the warm edge of zone 7.)

But the interior side needs to be air-tight, and no more than 5 perms.

Since you are using a bunch of different finishes, some of which are impossible to make air tight, the safest bet would be to use a "smart" vapor retarder such as Intello Plus or Certainteed MemBrain detailed as an air barrier between the cellulose and your finish wall.  They are class-II vapor retarders when the proximate air is dry (less than 35% RH), but become vapor open when the air is more humid (greater than 40% RH).  This characteristic limits the rate of moisture accumulation in the cavity during the cold weather, but allows it to dry rapidly when the assembly warms up in spring, releasing the stored moisture into the entrained air in the cavity.

Of course this approach still works whether you have foam in the cavity or not, and it's fine to use just the amount of foam (or caulk)  to air seal the sheathing, which doesn't take much if it's plywood.  A  full covering of an inch might be called for if it's plank sheathing though.