Upgrading Basement Insulation - Finishing the Job and Insulating the Garage Stairwell

If you've been following the past several posts - I've been upgrading the basement insulation in my 25 year old home, working on improving energy efficiency and indoor air quality. Following the installation of polyurethane spray foam in most of my basement walls with a spray foam contractor, I had half of a Touch-n-Foam 600 spray foam kit left to use up. We were in the process of re-closing all the basement walls - installing the drywall and getting the drywall joints taped and finished. I realised that I had not done anything with a stairwell in the back corner of my home - which runs from the heated utility space underneath my garage elevated slab floor and the garage. So I decided to attack that final section of the foundation wall - pull off all the drywall and use up the rest of the Touch-N-Foam kit.

Garage Stairwell - Drywall and 1.5" partial coverage of styrofoam removed

First step was to remove the drywall. The drywall had been installed before the stairs were installed - so the drywall was cut just above the framing of the stairwell. The drywall was removed to just below the level of the rim joist on top of the concrete foundation wall. There was a layer of foam sheet installed on the top of the foundation wall below the rim joist - no other sealing.

Rim joist. The styrofoam you can see here has been cast into the foundation wall - intended as a slot for pouring the elevated slab. Since the slab doesn't extend to this corner because of the opening for the stairwell, the builders left it in place. I decided to leave it in place as well, since it was cast in the foundation wall - and apply spray foam directly overtop. 

With the drywall removed, it was time to get started with the Touch-N-Foam kit. One of my lessons learned from the previous application was to get my hands on a 3M full face organic vapour cartridge respirator - which I did. I purchased the medium size - I have a pretty large head - and was able to get an effective face seal and performance.

3M Full Face respirator. 

On to the foam application. I started with foaming the corners, rim joist space, and the bottom wall cavities. 

Start applying foam on all corners, rim joist, bottom wall gaps. 

Once the perimeters were foamed - then I got onto the wall spaces. This time - I didn't have time to try to heat the concrete wall before the application of the Touch-N-Foam - I guess that my wall temperature was about 8 degrees Celcius (46 F) - below the recommended 16 C (70 F) minimum surface temperature recommended by Touch-N-Foam. What I found was that as the foam cured, it contracted slightly and pulled away from the wall studs. You can see the 1" wide gap in the photo below:

Note the gap next to the two studs - the foam contracted due to the low surface temperature of the concrete wall.

In my case this wasn't catastrophic - I justed gave the foam 30 minutes to cure, and then came back and foamed the gaps where they appeared, but it was interesting to see the effect of applying this product on a substrate that was below the manufacturers recommended application temperature.

Underneath the stairs - there was no insulation at all in this portion of the wall:

No insulation in this portion of the wall underneath the drywall.

So - this space was foamed as well.

In my other post about using the Touch-N-Foam kit - I wrote about what happens when you reach the end of the cylinder - and the resulting uncured foam and the requirement to physically remove it to prevent odours within the house. This time - I was much more vigilent when I was getting to the bottom of the cylinders - as soon as I noticed a change in the consistency of the applied foam - I immediately stopped applying the foam and checked the cylinders. A test shot into a garbage can confirmed that I had run out of the Part A chemical - and that it was time to stop applying foam. The photo below shows about 6 cubic inches of foam at the end of the application that did not have sufficient Part A in the mix. 

The end of the application of the Touch-N-Foam - some runny foam which only has Part B, and no Part A. 

This small amount of uncured foam was easy to remove with a putty knife, and I finished up the application with some single part foam from a spray can.

Re-applying the drywall over the foam installation. 

And, again, as desribed in the previous post - it is extremely important to cover all the spray foam with drywall to give you the fire resistance.

All in all - I am satisfied with the performance of the Touch-N-Foam kits - they are better suited for small to medium sized insulation jobs - such as a portion of a wall or a specific sealing job. Larger jobs - consider going with a spray foam contractor - which will be more cost effective and quicker.