Learn Why Insulation Must Stop Air Infiltration

Air infiltration can occur when there is a penetration in the building envelope allowing outside air to flow inside a building. This often occurs between seams of plywood sheeting or around window frames. Insulation can play a role in limiting air infiltration by filling all gaps and voids. For it to work effectively, insulation must be spray applied or dense packed into a wall cavity. In contrast, manufactured, pre-formed insulation batts cannot effectively fill these voids. In fact, they can exacerbate this problem especially around electrical outlets and light switches.

This photo of two walls shows the difference. The one on the left is insulated with fiberglass batts. The wall on the right has dense packed cellulose insulation. The difference is clear – the wall cavity is fully sealed with cellulose insulation. The batt insulated wall will allow air infiltration and reduce the effectiveness of the insulation – regardless of the R-Value.

The picture shown below may look like a haunted house, but it is another perfect example of insufficient insulation within the wall cavity. This picture, taken using an infrared camera, is of a home during colder winter conditions. The red and yellow areas indicate where heat is not being contained. Common areas are shown here including the roof ridge line, chimney and windows. But on the sides of the house, the red and yellow areas clearly show where insulation is lacking. Likely there are fiberglass batts in those walls allowing air infiltration.

These small penetrations often lead to air infiltration resulting in major comfort issues as well as increased energy costs. FTI’s flagship product, Fiber-Lite, is a perfect product for insulating walls. This product can be spray applied or dense packed to effectively fill all gaps and voids.

Learn more about the product here.