DIY Doctor UK DIY Forums

I have started to insulate my garden shed using glass mineral wool. The walls of the shed are just shiplap wood cladding on a wood frame. I intended to just fit the wool directly on the wood cladding inside, and then cover everything with MDF boards. However, someone recommended me to tack a breathable membrane to the walls before fitting the wool. Does this make sense? What difference will this make?

Yes. The membrane will allow moisture in the form of water vapour to escape from inside the building, avoiding a buildup of condensation. Kingspan explain it well on their website, google Kingspan breathable membrane for a full explanation.