Frequently Asked Questions
Do I need to remove the old insulation in my attic before installing sprayfoam?
We firmly believe in the importance of removing the old insulation: you eliminate potential smells, achieve a superior air seal, and prevent moisture-related issues.
Reason #1: Unwanted Smells or Odors
When closing the attic and moving mechanical components into the conditioned space, it’s vital to consider the potential smells associated with the old insulation. The insulation may harbor unpleasant odors from factors such as pests, pesticides, or even amines emitted during the spray foam application. While proper ventilation during the process helps mitigate these smells, there’s always a risk of the old insulation absorbing and retaining odorous substances. To ensure a fresh and odor-free environment, it is recommended to remove the old insulation altogether.
Reason #2: Achieving a Good Air Seal
A key benefit of spray foam insulation is its ability to provide a reliable air seal. However, leaving behind old insulation can compromise this seal. Even small gaps or unsealed areas can lead to negative pressure in the attic, causing the HVAC system to draw in warm, humid air. The condensed moisture can then promote the growth of unwanted substances and contribute to unpleasant odors. By thoroughly cleaning away the old insulation before applying spray foam, you ensure a complete and effective air seal, preventing moisture-related issues.
Reason #3: Condensation from Reduced Air-flow
In colder climates, where attics are warmed by heat migrating from the space below, it’s essential to prevent spray foam from becoming a condensing surface. When old insulation remains in place, it can impede the heat transfer, potentially causing the surface of the foam to become cold enough for condensation to occur. To avoid this scenario, it’s recommended to remove the old insulation entirely, ensuring proper heat transfer and preventing moisture-related problems.
What special treatment does open cell need?
Because open cell foam is not its own vapor barrier, it is required that you paint the interior surfaces of your drywall with a vapor barrier primer. Here is a link to the specs for that product.
What R-values do I need?
R-value is a measure of a material’s thermal resistance, or how well it insulates against heat flow. The higher the R-value, the better the insulation.
Open cell foam has an R-value of 3.8/inch, while closed cell has an R-value of 7/inch.
Because spray foam insulation creates an air seal, the only heat lost is through conduction. Generally, R14 stops 92% of heat lost due to conduction, while R21/25 stops 96%, R38 stops 98%, and R49 stops 98.3%.
In our climate zone, the minimum that one can have in their ceiling or roofline is R25. This insures a thermal break occurs within the foam, thus preventing warm-moist air from ever coming in contact with the outside cold (you know how the condensation collects on a glass of ice water—we don’t want that on your ceiling).
Typical custom home packages include R21 in the walls, R38 in the ceilings, and R14 in crawlspaces and garages. We do have some flexibility on this, so just ask.
A typical shop, if won’t be heated all year, is done at R14.
Can I paint over the foam?
Yes!
The foam will start out sea green (closed cell) or white (open cell). Upon exposure, it will yellow over time. Some folks have opted to paint directly over the foam for aesthetics.
Testimonials
“I was just showing someone the nice insulation job you did for us, and noticed that Darry insulated a tight corner space upstairs where the addition meets the old house. I almost asked him if he could spray that small cavity, but didn’t want to bother him. Thank you for noticing and taking care of that problem area.”
—Harold, Sandpoint
Let's Start a Project
In most cases, we can get you an estimate over the phone or by email. We may ask you to email us plans and/or photos.