What’s missing in this foundation repair?


By John Haysom
Here’s the scenario: For some reason, the foundation of this house needed to be repaired – perhaps it was leaking, perhaps it had settled unevenly. The homeowner hired a contractor to repair it. The contractor excavated all around the foundation. Looks like he damp-proofed the wall; perhaps he put in new drainage tile, now covered with granular backfill. This looks a lot like foundation repair jobs I’ve seen around the neighbourhood recently.
Is the job ready for the final total backfill?
No!
What’s missing is the insulation!
Many Glebe residents don’t realize their houses lose a significant amount of heat through basement walls to the cold soil outside and to the cold air near the top. The Ontario Building Code now requires all house foundation walls to be insulated. The requirements are based on life-cycle cost-benefit analyses. Of course the economics of insulating the foundation walls of an existing house are not nearly so favourable due to the cost of excavation. But if you’re going to excavate anyway for other reasons, it makes economic sense to insulate at the same time, before you backfill.
Even if the foundation is already insulated on the inside, this is a good opportunity to increase its thermal resistance very economically.
So if you’re contemplating a major foundation repair for your house, ask the contractors to include recommendations for the amount, type and cost of insulation in their quotes.
Long time Glebe resident John Haysom is an engineer retired from the Institute for Research in Construction of the National Research Council where he worked on the development and maintenance of national model codes such as the National Building Code and the National Energy Code.
