DIY foam to use for insulating in attic arround skylight?
#1
DIY foam to use for insulating in attic arround skylight?
Hi,
We replaced the skylights in my townhome as a HOA project.
I noticed that there is a gap visible between roof and skylight frame. I can see light cumming through form the skylight channel.
I like to insulate that gap with some foam. In the process I woudl like to cover the 2x4 frame. I realize, professional spray foam woudl be best.
However, are there any DIY foam products I could buy? I think most foams at big box stores are gap fillers only...

We replaced the skylights in my townhome as a HOA project.
I noticed that there is a gap visible between roof and skylight frame. I can see light cumming through form the skylight channel.
I like to insulate that gap with some foam. In the process I woudl like to cover the 2x4 frame. I realize, professional spray foam woudl be best.
However, are there any DIY foam products I could buy? I think most foams at big box stores are gap fillers only...


Last edited by PJmax; 12-15-19 at 04:52 PM. Reason: resized pictures
#2
I noticed that there is a gap visible between roof and skylight frame. I can see light cumming through form the skylight channel.
A much bigger problem than foam will cure!
#3
the gap in the images is between rood and frame. However, the light is not coming directly from outside. It is coming from the inside of the house. The reason. the original skylight size is no longer manufactured. So, they installed a slightly shorter one and fitted a quarter trim inside the skylight channel. Light is coming though form there. Not happy about it, but short of taking a lawyer I tried everything. I am trying to make sure no air is passing though form attic into living space.
#4
I found some small foam kits, none seems to have great reviews...
https://www.amazon.com/Touch-4004520...ADE09KZFJW2MZZ
https://www.zoro.com/handi-foam-insu...yABEgIcQPD_BwE
https://www.homedepot.com/p/Touch-n-...2506/204352574
https://sprayfoamkit.com/products/sp...ch-repair-kit/
I don't see any apparent differences between those products. I will need to be able to spray up a bit.
https://www.amazon.com/Touch-4004520...ADE09KZFJW2MZZ
https://www.zoro.com/handi-foam-insu...yABEgIcQPD_BwE
https://www.homedepot.com/p/Touch-n-...2506/204352574
https://sprayfoamkit.com/products/sp...ch-repair-kit/
I don't see any apparent differences between those products. I will need to be able to spray up a bit.
#6
I haven't used any of the kits you linked to but I have used a kit that had a pair of tanks that looked like small bulk propane tanks.
I will say that there is a definite learning curve to using these, how long to hold the trigger of the spray gun, how fast to move the gun and how full to fill the cavity. These things spray out almost like thick paint, maybe a 1/4 inch thick layer and then they foam up. It is amazing to see this 1/4 inch layer foam up to 3 inches or so in thickness in just a couple of seconds and then harden in less than a minute but it also makes it hard to determine just how much to spray initially. Once it is sprayed there is no taking it back.
The foam, especially the initial spray, is extremely sticky and you WILL get it on your hands and most likely your clothing. Nothing takes it off after it cures and it cures so fast you don't have time to wipe it off before it cures. Any excess needs to be cut off. You need to plan your job to minimize the time that you are NOT spraying as the material mixes in the gun nozzle and once mixed it hardens in less than a minute. The kit I used specified a maximum of 20 seconds between spray bursts and they weren't kidding. If you spray, stop and wait for a minute before spraying again you will find the nozzle full of cured foam. This is why they include a few extra nozzles with the kit.
The canisters need to be at a minimum temperature or the crap simply doesn't flow properly. With the kit I used (I think it was a Handy Foam kit) it was necessary to shake the canisters before using and shake again every several minutes. Disposal of the used system can also be problematic. I had to "waste" the final contents of the canisters and then eventually take a hacksaw to the "empty" canisters to make it acceptable to the residential waste hauler in my area (read, put in garbage can). The residual contents of the canisters is nasty and slimy to the skin.
On the other hand, it DOES an excellent job of sealing and insulating as long as you don't mind a bit of overspray.
I will say that there is a definite learning curve to using these, how long to hold the trigger of the spray gun, how fast to move the gun and how full to fill the cavity. These things spray out almost like thick paint, maybe a 1/4 inch thick layer and then they foam up. It is amazing to see this 1/4 inch layer foam up to 3 inches or so in thickness in just a couple of seconds and then harden in less than a minute but it also makes it hard to determine just how much to spray initially. Once it is sprayed there is no taking it back.
The foam, especially the initial spray, is extremely sticky and you WILL get it on your hands and most likely your clothing. Nothing takes it off after it cures and it cures so fast you don't have time to wipe it off before it cures. Any excess needs to be cut off. You need to plan your job to minimize the time that you are NOT spraying as the material mixes in the gun nozzle and once mixed it hardens in less than a minute. The kit I used specified a maximum of 20 seconds between spray bursts and they weren't kidding. If you spray, stop and wait for a minute before spraying again you will find the nozzle full of cured foam. This is why they include a few extra nozzles with the kit.
The canisters need to be at a minimum temperature or the crap simply doesn't flow properly. With the kit I used (I think it was a Handy Foam kit) it was necessary to shake the canisters before using and shake again every several minutes. Disposal of the used system can also be problematic. I had to "waste" the final contents of the canisters and then eventually take a hacksaw to the "empty" canisters to make it acceptable to the residential waste hauler in my area (read, put in garbage can). The residual contents of the canisters is nasty and slimy to the skin.
On the other hand, it DOES an excellent job of sealing and insulating as long as you don't mind a bit of overspray.
#7
thank you for sharing. This is very helpful. I think this type of spray foam is ideal for my small attic-skylight project.
I don't know if there is any difference between the brands. It seems that smaller units get the worst reviews. Larger better.
However, I like the idea of smaller ones. I can do one skylight avoiding clogged nozzle and crawl to the next skylight using a new canister.
I don't know if there is any difference between the brands. It seems that smaller units get the worst reviews. Larger better.
However, I like the idea of smaller ones. I can do one skylight avoiding clogged nozzle and crawl to the next skylight using a new canister.
#8
So, I ended up buying 3 of the Home Depot product:
https://www.homedepot.com/p/Touch-n-...2506/204352574
In summary, I can't recommend.
Initially, I bought two.
#1: worked well, better than expected
#2: had the black release broken out of the store. Noticed a bit late and already had one side liquid coming out. Was able to returnand got a second one.
#3: started ok. But about 1/3 into it the mix started to change and the foam did not dry
https://www.homedepot.com/p/Touch-n-...2506/204352574
In summary, I can't recommend.
Initially, I bought two.
#1: worked well, better than expected
#2: had the black release broken out of the store. Noticed a bit late and already had one side liquid coming out. Was able to returnand got a second one.
#3: started ok. But about 1/3 into it the mix started to change and the foam did not dry