I entered into the topic of cavity wall insulation with some bewilderment. At first, I thought I knew what I was getting into. Then, I discovered that I was on unfamiliar ground.
See, I'm located in the U.S. We have walls here. Our walls have cavities. They need insulation. Add them all together. Do you have cavity wall insulation?
Cavity Walls - Background
Cavity wall insulation is a uniquely UK term. It refers to masonry walls (brick) that were built with double-wall construction. This practice began around 1920, but really picked up around 1935. It's not completely certain why this practice came about, but there are two logical reasons:
- Cavity walls provide a damper against the damp. Single-wall (or solid-brick) construction allowed for condensation on interior walls. The air buffer between the two walls prevented moisture in the homes.
- Cavity walls are cheaper to build than solid brick walls.
This is not to say that no one in the United States has cavity walls; we're just saying that cavity wall insulation is the term used in the UK.
Do You Have Cavity Walls?
You might have cavity walls if:
- You have a detached or semi-detached house.
- Your walls are brick.
- Your walls are around 30 cm thick (23 cm thickness would mean solid walls).
- Your house was built between 1920 and 1995.
Comments
cavity walls are still prevelant in wingwall applications. mainly for the cost advantage. Good place to hide brick waste and unused sand and mortar to provide sturctural rigidity to the cavity as well.
but if the cavity wall is meant to prevent moisture from getting into the building then the moisture has to get out through weep holes. if the insulation fills up the entire gap then how does the moisture get out? its just like a single wythe wall and water damage will be imminent.