The winter vortex has been good for the diagnostic business and the work is always interesting. We’ve been doing a lot of dynamic testing using the infrared camera along with the blower door to non-destructively test and pin point envelope failures. I recently had the chance to check out a house in Maple where the water line to the 2nd floor master bedroom’s en-suite toilet would freeze when the weather was cold enough.
The back side of a housing development in Maple Ontario showing the 2nd floor bath bump out.
This cutesy bump-out sure looked nice, but it was causing some issues. Let’s look inside to see what was inside the the bump-out…
The bath tub straddled the main floor wall ensconced in this back bump out. Note the electric heater was plugged into a GFCI. The toilet bottom left had frozen pipes when the temperature outside dipped.
The image on the left was taken in the morning on the north face of the house, the one on the right was taken after 15 minutes of pressurisation with a blower door. The air leakage through the cantilevered floor cavity at the double trimmer joists on either side was significant enough to produce a significant increase in outside temperature.
On the whole, it appears the easiest solution would be to drop the exterior soffit and seal the floor cavity in the plane of the main floor wall below it, then insulate and replace the soffit.