Attic dropped soffit air sealing

[Certificate of Excellence]

That's great. I love spray foam insulation but dont have a gun - I think my garage definitely needs one of those. I just got stuck in the lurch of not having the right tool for the job today. I was replacing a ceiling fan in the home that had become wobbly and unstable at its Jbox and I realized I did not have a sub 1 inch deep socket set (only larger sets for working on my rides) and because of this, a two minute job securing a new Jbox mount took 15 minutes having to inefficiently complete the job with 1/4 turn of t&g pliers. I got it done but it was unecesarily tiring, way more time and Ipinched the crap out of my finger. All of this would have been circumvented had I had a deep socket set for under 1" nuts.

Guess what I am asking Santa for this year

Oh yeah, forgot to ask - what are you using to affix the EPS foam board to the walls/roof?

 

[alxlab]

To attach the EPS boards temporarily while the spray foam sets I used so 2 3/4 construction screws to hold them. The pieces of board are small are light so alone need 2 or 4 to hold. Most are srewed in diagonally. You can see some screws that I haven't fastened yet in this picture.

I also use so screws with rigid insulation washers which are made specifically to fasten board insulation to walls. Here's some screwed into a 2x6 in the wall.

The idea is that I don't want the spray foam to get behind and lift the boards away from the wall and ceiling drywall. You want to try to have no gaps if possible. The spray foam is to ensure no air will travel between the walls and the attic. The spray foam I'm using in the gun is call Enerfoam. It's minimanlly expanding, can be used as an adhesive and as a fireblock (in the US). Pretty good stuff. If this wasn't the attic and easier to access I would probably not use screws and just but a piece a wood againts the boards with a brick to hold them up. That reduces the chances of creating a hole that air can leak in through and reduces thermal bridges. Doesn't hurt to put aluminum take over the screws after.