Rat-trap bond
Cavity brick wall
Born in India (popularised by Laurie Baker).
How it works
Bricks laid on edge so each course leaves a hollow air gap inside the wall. The trapped air slows the sun's heat crossing indoors, and the bond needs about a quarter fewer bricks and less mortar than a solid wall.
In a modern home
A cooler, cheaper, lower-carbon external wall for a load-bearing home; the cavity does the work an extra layer of insulation would.
What it answers
Built from
Source
Laurie Baker and COSTFORD cost-effective building manuals.
Follow the threads
Mudbrick catenary vaultshares overheating, high embodied carbon, store & slow heat→Earth-sheltered cave dwellingshares overheating, high embodied carbon, store & slow heat→Filler-slab roofshares high embodied carbon, store & slow heat, cool→Thick earthen wallsshares overheating, high embodied carbon, store & slow heat→Handmade oxide floor tilesshares overheating, store & slow heat, cool→Insulating & green roofsshares overheating, store & slow heat, cool→