Materials
Insulation types & R-value
Batt, loose-fill, rigid board and spray foam — how their per-inch resistance compares and where each one earns its place.
Insulation · Air Barriers · Weatherproofing
Reading the building envelope, one assembly at a time.
Plain-language technical notes on insulation types, air and vapour control, and window sealing for Canadian heating climates — with references back to published code and federal guidance.
Topic library
Three assemblies that decide how a house holds heat.
Each entry walks through the materials, the order of operations, and the moisture rules that keep an upgrade durable rather than just warmer for one winter.
Moisture
Air & vapour barriers
Why air leakage control comes first, and how the 1/3–2/3 rule keeps the vapour barrier on the warm side of an assembly.
Detailing
Window sealing & weatherproofing
Caulk versus weatherstrip, where each belongs, and how sealing intersects with Canada's current home-efficiency funding.
How to read these notes
Sequence matters more than any single product.
Seal, then insulate
Natural Resources Canada describes air leakage control as the first retrofit activity, ahead of adding insulation, so moisture is not driven into a newly filled cavity.
Keep the warm side dry
The vapour barrier belongs within the warm inner third of an assembly's thermal resistance — the 1/3–2/3 rule referenced throughout the federal retrofit guidance.
Check the local code
Minimum R-values, air barrier and ventilation requirements are set provincially and follow the National Building Code; confirm specifics with your building authority.
Assess
Air-seal
Insulate
Vapour control
Verify
A working order
The same five stages run through every assembly on this site.
Assess where heat and air are escaping, seal the leaks, add the right thermal resistance, control vapour on the warm side, then verify the result before closing the wall.
Contact
Questions about a topic on this site?
Send a note and we will read it. This form runs entirely in your browser for a static site, so nothing is transmitted or stored on a server.