Bathroom Insulation and Ventilation
I get a lot of questions about moisture in the bathroom, specifically rooms with showers. While bathroom moisture vapor in the air can be transferred through walls and ceilings, the real issue is when moisture vapor becomes trapped in walls, resulting in mold and mildew growth. Mold is unhealthy and can damage your home and present a potential health concerns.
So how do we enjoy the hot steamy showers and avoid mold problems? The answer is a combination of using the proper insulation combined with excellent ventilation.
Let’s talk about vapor barriers. The level of vapor control required on the interior side of framed walls with fiberglass, rockwool, or cellulose insulation is determined by local building codes, which are based off the Department of Energy’s climate zones for construction.
In my neck of the woods we used fiberglass or Cellulose insulation and a plastic vapor barrier for years, and this method still works well. Lately I’ve been using spray polyurethane foam (SPF), which, at least in North America, is fast becoming one of the more popular options for new and remodeling insulation methods. I should note that it is the MOST expensive option available.
What is SPF?
Spray polyurethane foam is a heat-activated polymer that is sprayed into place, turns foamy, expands and then eventually hardens in place. The best part of SPF is that it fill all gaps and crevices that fibourus insulation cannot reach, this sealing off air leaks in the process.