What would you do with a small cavity in an otherwise solid brick (1905 ish) house?

[low_and_there]

Our house is solid brick except for a couple of sections of the front wall to either side of the square bay window, where there is a 2-deep solid brick wall, then a small cavity of about 45mm, then another wall of brick to the inside face.

 

One person I showed this to suggested that I fill it with some loose fill (breathable) insulation. It's probably doable, but would be a bit tricky to do. The only reason I saw it is because a single brick has come out there.

 

Would you put insulation in, or leave it as air? I'll post a pic in a mo.

 

 

[low_and_there]

[Iceverge]

Injected Closed cell foam like Walltite would give you the best insulation for the cavity width but it's not cheap. 

 

https://youtu.be/z7c_vMCzZ-g

 

EPS beads are much cheaper buy may not flow well in such a small cavity. 

 

Avoid injected mineral wool or open cell foam. 

[bakingjames]

You’ve not got a meaningful cavity when it comes to insulation. I would treat it as a solid wall. If you’re planning on insulating your solid walls (everyone should be at some point), then I’d just stick whatever system you plan on using over the cavity areas too, whether that’s internal or external.

 

If you’re going fully vapour open (breathable), just be careful, enlist help of your insulation merchant/architect with regards to moisture.

 

james