I have to close some gaps under an overhang on my roof, to prevent rain entering.

Since there is little space between roof and overhang, it is difficult to reach. Spray foam obviously would be the ideal solution, though it's not easy to work with PU foam as it keeps expanding.

I had a Thai worker give it a try, and the result was kind of a disaster, as it expanded too much, and then to cut it out was very difficult because of the limited space.

So is there a foam in spray bottles that expands less than the regular PU foam?

 

I used the TOA PU foam, and that definitely expanded too much

Get the spray bottle with a whistle .

 

You just spray and blow the whistle when you want it to stop exploding.

show some pics

On 10/15/2025 at 8:43 AM, CallumWK said:

I have to close some gaps under an overhang on my roof, to prevent rain entering.

Since there is little space between roof and overhang, it is difficult to reach. Spray foam obviously would be the ideal solution, though it's not easy to work with PU foam as it keeps expanding.

I had a Thai worker give it a try, and the result was kind of a disaster, as it expanded too much, and then to cut it out was very difficult because of the limited space.

So is there a foam in spray bottles that expands less than the regular PU foam?

 

I used the TOA PU foam, and that definitely expanded too much

Look for foam thats for Windows/Doors, thats going to have the least amount of expansion.

Personally, I'd just use reg. foam,  don't try and fill the whole gap. Spray some, move to the next spot and so on. Go back to the start and you'll see how much more you need or don't. Finish it out

EDIT: The can foam in this country is really hot so a little goes a very long way. Way hotter than anything we get in the States.

1 hour ago, Slowhand225 said:

Look for foam thats for Windows/Doors, thats going to have the least amount of expansion.

 

Yes that is the kind I'm looking for, but don't know how to recognize it.

 

I found online some from Soudal, but you need a spray gun for it.

52 minutes ago, CallumWK said:

 

Yes that is the kind I'm looking for, but don't know how to recognize it.

 

I found online some from Soudal, but you need a spray gun for it.

Soudal is the best there is and the gun is cheap, Lazada has them.  You can also put clear tube on the end of the gun and make it as long as you need.

Whole different foam from what the box stores sell. It will say something like "Low expansion" or 'Windows and Doors"