Sometimes it is the little things that get you.
However, these little things can end up costing you a lot of money over time.
At a recent inspection I had a house where the insulation details were not well thought out. Without going into a discussion about the “type” of insulation, lets just discuss in the simplest of terms how the system was working—or not working as the case might be.
The following sketch shows how the walls are insulated up to the ceiling and then the roof plane itself is insulated. What got missed was the wall between the roof and the ceiling. This space above the ceiling is essentially “conditioned” space and the short wall between has to be insulated to have continuous insulation around the conditioned space.
This next picture shows what that un-insulated area looks like with thermal imaging from the exterior. However this is a space between the second floor and the main floor ceiling.
Going back to the original drawing, here is an exterior view of that un-insulated space—as seen by thermal imaging. The un-insulated areas appear warmer (the white-yellow areas)
The same areas of the above picture as seen from the inside of the attic space with the un-insulated areas appearing “cooler” (the black areas).
These areas will need to be well-insulated to prevent wasting of energy that increases both heating and cooling loads of the home.
The fiberglass insulation should be encapsulated, and for more information about that: All Fiberglass Insulation Must be Encapsulated.
Charles Buell, Real Estate Inspections in Seattle