Whilst renovating my kitchen I exposed an old vent hole that had been stuffed badly with polystyrene packaging and the render has been patched over outside. It is roughly four inches round by eight inches deep.
I considered either sand and cement; or maybe expanding foam. Not sure what is best and obviously want to avoid causing myself damp issues later. This is a 20s house with lime mortar and render.
I considered either sand and cement; or maybe expanding foam. Not sure what is best and obviously want to avoid causing myself damp issues later. This is a 20s house with lime mortar and render.