Upgrading Basement Insulation - Completing the Job with a Spray Foam Contractor

I've written a few posts about my project to upgrade the insulation in my basement perimeter walls. The bottom two feet of the foundation walls had no insulation, just the top 6 feet of the 2x4 stud walls had 6" batts of fibreglass insulation and a foil backed paper vapour barrier.

I started the job thinking I could achieve enough coverage with the Touch-N-Foam System 600 kits - but found with experience that although the kits provide good quality foam, they are slow to apply in quantity, and multiple passes are required to get the three inches required for the foam to act as a vapour barrier.

Contractor Installed Demilec Heatlok Soya Medium Density Spray Polyurethane Closed Cell Foam Insulation

So - I called and made an appointment with an insulation contractor, one that had previously sprayed foam in my attic around a skylight. This contractor sprays Demilec Heatlok Soya - a medium density spray polyurethane closed cell foam that is manufactured in Canada, and the United States. 3" of this foam replaces the requirement for a vapour barrier. Some features of this product:

• Zero Ozone Depletion Substances (ZODS) as defined by the Montreal Protocol
• RSI 1.05 per 25mm (R6 per inch)
• ASTM E96 Water Vapour Permeance, 50 mm 37 ng/Pa.s.m2 (0.65 Perm)
• CCMC 07273 Air Barrier Material, 25-30 mm 0.00004 L/s/m2 @ 75 Pa
• Contains post consumer recycled plastic, and Soya oil. I'm not sure the content of recycled plastic in the foam, but according to the company they've diverted 300 million plastic bottles since 2004 - which is an interesting statistic. 

For full information on this product, look up it's technical datasheet on the internet.

The contractor visited, took measurements of the surface areas and thicknesses to be installed, and also checked out the Touch-N-Foam installation that I had installed a few days earlier. I happy that the contractor thought that the final result was good quality foam, good adhesion to the concrete foundation walls, and good consistency. He didn't see any issues with applying his foam overtop of the Touch-N-Foam to increase the foam thickness from an average of one inch, to four inches.

Prior to the arrival of the foam conractor, make sure that you are ready for the foam installation, by ensuring that all electrical, automation and home entertainment cabling was completed. In my case, I had some home theatre surround wiring to run before the foam was installed, and I also made sure all the electrical wiring was supported properly with ties, ensuring there would be nothing hanging in the gap between my floor slab and the foundation walls. 

Home theatre surround speaker cabling pulled prior to foam installation, coiled and protected in a plastic bag prior to the foam installation

Electrical wiring zip tied and suspended from inner wall studs, to clear the gap between the slab and wall for best possible foam application

When I was removing the drywall from the foundation walls, and removing the old fibreglas batt insulation from the walls, I found two thin vertical cracks in the foundation walls - both were located at corners of basement wall cutouts in the foundation wall. It's important to resolve and cracks or leaks prior to applying spray foam. Particularly cracks in concrete - it is important to have a structural repair done which maintains the strength, integrity and waterproofness of the wall. I'll describe how I dealt with these vertical cracks in a new post.

Thin vertical crack behind one of the wall studs. Note the efflorescence (white powdery substance) on the wall next to the crack.

In a few days, the contractor arrived to install the foam, and started by masking off all the electrical outlets, and cover all exposed carpet, furniture, painted wall surfaces, etc. from overspray using painters plastic sheet. This is very important - this material is extremely sticky and difficult to cleanly remove from finished surfaces. 

The contractor uses special equipment installed in a cube van or truck - the raw materials are pumped at high pressure via a 300 foot long heated hose into the home, mixed in the heated application gun, and expand and cure in seconds once the mixed foam hits the application surface. Since this foam is essentially manufactured in the home - it is very important to use an experienced, licensed contractor that will take responsibility for the installation, and responsibility for any application issues. 

There are things that can go wrong with a foam installation, this could include things like overheating following installation, potentially causing undesired chemical byproducts and odours, and even possibly fire. It's important that the installation contractor follow the foam manufacturer's guidelines for single and multipass application thicknesses - foam applied too thick can cause potentially serious consequences. Discuss this with your contractor and ensure that you are satisfied with the responses you receive. Since you shouldn't be in the vicinity of the applicator while it is being installed, without wearing an organic carbon respirator, you won't be able to monitor the installation yourself. You'll have to rely on the experience and reputation of your contractor. Protect yourself by asking questions, checking references, and working from a written quotation and contract. Verify your contractor's license number, and if possible, do a search on the license number to ensure the license is valid, and there isn't a history of complaints or issues with the contractor. In the worst case, the consequence of a bad spray foam insulation job is the complete removal of all the foam - which can be difficult and time consuming. Some verification and research here could save massive headaches later. We selected a contractor called Isolam from Varennes, QC, and were perfectly satisfied with their experience, application and performance. 

Contractor installing spray foam - note the full coverage suit, and the respirator supplied with fresh air from the truck

The spray foam expands and cures rapidly, but it will off-gas for several days creating a faint chemical odour in your home. You may wish to let it aerate for a few days if you can afford staying elsewhere. It's now been a week since the application of foam, and the chemical odour is now barely noticeable, We're currently in the process of topping up the insulation in the wall spaces with our leftover fibreglas batt insulation, and installing new drywall. The installation of drywall should help to reduce the residual odours in the home, and continuous ventilation until all traces of the chemical odour may be a good idea. It's also important to note that the spray foam needs to be covered with at least 3/8" thick drywall as a fire barrier in order for the insulation to meet the Canada national building code - your contractor should mention this fact when the job is quoted, and you'll likely have that specific point noted on your invoice.

Spray foam is excellent for sealing air leaks in and around the rim joists around the circumference of the home at the edges of the floors. It's worth opening the drywall or ceiling to access these spaces. 

So - in summary - I believe that a proper, well applied, closed cell spray foam insulation is one of the best ways of insulating a basement located in the snow belt, and here are the most important points that I've found with this project:

• Get all your wiring, central vac, ventilation, and all other in wall services completed before the spray foam contractor arrives;
• Use a licensed contractor, with an experienced applicator, that warrants their work and will follow the foam manufacturer's application guidelines, particularly with respect to application thickness; 
• Correct all wall cracks or water leaks prior to the installation of the foam;
• Vacate the house during the application, ventilate the house very well following the installation of the foam, and you may wish to leave the house for a few days while the foam cures and off-gasses.
• Ensure the fire break is installed over the foam following the foam installation, per the manufacturer's recommendation and any building code requirements - such as a cover of drywall. 

I'm thinking about having my blower door test redone, to check to see if this foam installation has greatly reduced my air leakage rate. I'll get all the drywall and crack repairs completed first, then report the results when I get the blower door test completed. Stay tuned for further posts on the crack repairs, and the continuation of the indoor air quality project.