When a 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 floor as well as any penetrations in the floor with 2 pound closed cell spray foam code R30 5 inches of foam which gives us a complete air and vapour seal and a dramatic cut in heat loss.
Cold Floors/Rooms Above Garages
The building codes in many areas dictate that these floors should be insulated to R-28.5 (RSI-5.02). But experience tells us that R-28.5 of batt insulation does not ensure a warm floor. In theory, the floor in a properly insulated room should be at room temperature. In reality things are quite different; it is common to find floors that are 10 F (5.5 C) colder than the room in Winter. Why? Because it is virtually impossible to install a fiber batt so that it is in contact with, and stays in contact with, the floor above. It is also impossible to install it accurately around bracing and bridging between joists. Unfortunately, due to voids, gaps and air spaces that allow air movement, fibrous materials do not perform to their rated R-value. (R-values are determined under ideal laboratory conditions.) Because air gaps usually exist between the floor and insulation there is room for cold air to infiltrate from the exterior. The cold air essentially "short-circuits" the insulation material and renders it much less effective.
Cold Floors/Rooms Above Garages
Some designers and builders have tried to overcome this problem with heated hotboxes using a dropped ceiling in the garage creating a cavity between the garage ceiling and bedroom floor above. Conditioned air is then pushed in to the space to heat the cavity and in theory this will heat bedroom floor. The problem is cold air from the outside still infiltrates the cavity and overcomes the warm air leaving the hotbox a coldbox.
Air sealing and insulating with spray foam is the solution
Spray foam insulation expands to fill the tiniest and most awkward spaces and adheres to the floor above. Spray foam also eliminates voids and the resulting air movement that has plagued generations of builders and homeowners.
How do we fix the problem
The first thing we do is remove the drywall and fiberglass from the garage ceiling. With spray foam sprayed directly to the underside of the bedroom floor heating the hotbox is no longer necessary, which will save in energy costs as well.
Open exposed (cottage) floors
The major side effects of a poorly insulated and air sealed floor are cold floors and drafts from infiltration. Other side effects include issues with moisture, rotting, radon gas, condensation, and rusting or corrosion of the mechanical system 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 to the underside of the floor not only creates an air seal and insulates the floor It also seals all the cracks and holes where rodents and insects enter our homes and cottages. The foam also will protect your wood floors from soil moisture rising from the ground to slowly rot your wood. Installing fiberglass batts under 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 the wood, not to mention creating a more pleasant environment for rodents.
