How to Air-Seal Doors with a Spray-Foam Gun
Remodeling contractor Mike Sloggatt demonstrates how to use a professional spray-foam gun to make a door more energy efficient.
Remodeling contractor Mike Sloggatt demonstrates how to use a professional spray-foam gun to make a patio door (or any door) more energy efficient
I’m going to air-seal by spraying foam around the perimeter of this door jamb.
I use a foam dispenser gun with a nozzle attachement that threads onto the end and lets me spray into the tight spaces around the jamb. Another thing I like about a pro foam gun is that the foam is released at the very tip of the nozzle; this means that the foam stays fluid inside the gun. I’ve accidentally left a can on my gun for as long as two months and still been able to dispense the foam. With a pro gun you also use the entire can; you don’t have the waste that is typically stuck in the end of a disposlable, straw-type spray-foam can.
It’s important to use the right type of foam. Get a low-pressure, low-expansion, and closed-cell window-and-door foam. The closed-cell is going to stop the air movement, and the low pressure and low expansion is important because it won’t distort the frame. High-expansion foam can bow the jambs out and prevent the door or window from opeing properly.
The last thing I’ll do on the inside of an exterior door is seal the sill pan to the door threshold. I’m going to use a sealant for that because air could blow in, and when there’s air moving in, water could come with it.I put some painter’s tape over the visible portion of the threshold while I caulked and tooled the joint wher it meets the floor.
After the foam and caulk has cured, I go back and trim any excess foam that is out past the jamb. If I notice any voids in the foam, i’ll come back and touch them up with the foam gun. That will take care of the air-sealing and we can move on to door trim.
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It seems everytime I'm doing a certain job I look at my fine home building mail and they are writing about it there information is always on the money once again your details are helpful
I see these pro spray-foam guns used all over the Fine Homebuilding site and magazine but have been unable to locate one. The big box stores don't have them and neither do the speciality stores here in Austin. Where would I find one and what brands of foam are available?
Try A Warehouse Full,
https://www.awarehousefull.com/search.php?search_query=soudal
And, FWIW, they're available at my local Big Orange Box,
https://www.homedepot.com/p/OSI-Quad-Foam-Dispensing-Gun-1413066/206524501
As Sloggat mentions, low expansion foam is important, to avoid distorting the door frame. BUT, even low expansion foam can warp a jamb if you squirt in a big glob. (Ask me how I know...) 1/4" wide, 1" deep, probably no problem. Half inch wide, 2" deep, better to do it in 2 passes, 5-10 minutes apart. Some of the modern 5/8", finger-joint, radiata pine jambs will distort in a light breeze.
To Eric: I faced the same problem as you. Very frustrating indeed. In Austin, go to ABC Roofing east of I-35.
Great advice, particularly about caulking along the bottom! Gotta look for one of those nozzle attachments too!
1:08 What? Sealing for water (and air) by caulking the inside of the sill? Isn't that the reason for slightly sloped rough door sills and a couple of ribbons of sealant along that sill before installing the aluminum door sill/frame?
The video with Mike Sloggatt showed the foam butting up to the wood shim locations. Air leakage can occur between the shims. Going back over the shims with the same sealant used at the sill pan would make a more complete and air tight door.
Steve Williams
BLF&R Architects
Yarmouth Port, MA
One other hint- use a Magic Marker or a knife to scratch an index line on the knob of the gun at 12 o'clock- that way you can reproduce settings- maybe 2 full turns for big gaps, 1-1/2 for jambs, 1-1/4 for a really thin bead for small cracks.
Dow has a new compressible foam intended as a drywall gasket- a 3/8 bead will mash down to a 32nd, so it will fill gaps but also compress in a high spot. It's kinda spendy and may be hard to find, but really useful in some situations. For example, I used it around the lip of some "airtight" LED lights to make a gasket at the drywall interface.