Spray Foam Insulation

2012 to 2017 Consumer Choice Award Winner for Insulation Contractor

Best Way to Insulate a Floor


When the floor over is poorly air sealed, air can leak through a number of locations, such as the band joists, structural framing, and knee walls. Air leaks can lead to a host of issues, such as cold floors, freezing pipes, and chilled duct runs that prevent the HVAC system from working properly. A poorly sealed floor cavity has a significantly reduced R-value and isn't much better than a floor cavity with no insulation at all. Air sealing the floor cavity properly is key. At Red River Spray-On we completely seal the band joist area and the subfloor as well as any penetrations in the floor with 2 pound closed cell spray foam at about 2-3 inches of foam which gives us a complete air and vapour seal and a 90-95% cut in heat loss.



Exposed Cottage Floors

Cottage floors have many penetrations and that aren't completely contained within the floor cavity. It's difficult to install an air barrier in a crawlspace without moving these protrusions into the conditioned space. The major side effects of poorly insulating and air sealing at the floor line are cold floors and drafts from infiltration. Other side effects include issues with moisture, soil gases, condensation, and rusting or corrosion of the mechanicals not including rodent and insect infestation.

In the winter time, those of us with raised houses suffer from cold, moist wood floors and in the summertime we lose much of our conditioned air through our floors. Applying Spray Foam Insulation under the wood floors or under subflooring not only creates an air seal and insulates the floor, but it also seals all the cracks and holes where rodents and insects enter our homes. The foam also will protect your wood floors from soil moisture rising from the ground to slowly rot your wood. Installing fiberglass batts under your floors can be a huge mistake because they tend to drop a few inches creating an air gap where moisture can penetrate and wreak havoc on your wood, not to mention creating a more pleasant environment for termites and rodents.