are cavity trays needed? Damp can be a major issue in the home. Find answers to questions or post your own here.

[gags37]

I'm thinking of adding a porch. It would be joining an existing rendered cavity wall and part is stone/slate cladding. Are cavity trays needed for rendered walls or are they just required were the extermal wall is face brick? There is also some foam insulation in the cavity.

[welsh brickie]

you dont need cavity trays,the render is providing protection to the elements

[gags37]

thanks for reply, just curious, am I right in what I said previously, are cavity trays only needed for facebrick walls?

[welsh brickie]

cavity trays are needed over lintols but not needed on a gable end

[gags37]

ah so i will need them as the porch would be in front of an existing doorway?

[andy01]

if the render is cementitious based it will still need cavity trays. we detail cavity trays over all openings

[thedoctor]

For readers looking for related advice please see our cavities DIY how to projects pages which covers stuff like damp issues and fixes, vertical Dpc, insulation of cavities, cavity trays and lintels and pumped cavity walls.