I'd be grateful for some building advice.
The rsj above our patio doors is rusting and expanding and cracking the render. I've inspected and it looks like there was no cavity tray fitted when built (c1970's).
Apart from fitting one, i'd been thinking about cladding the outside of the building with wood. On the basis that it would provide an adequate moisture barrier so that in theory no more moisture would get into the cavity wall. Would that solve the problem? Thanks