are cavity trays needed?

by **gags37** » Sat Mar 05, 2011 8:10 am

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.

by **welsh brickie** » Sat Mar 05, 2011 1:04 pm

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

by **gags37** » Mon Mar 14, 2011 10:12 pm

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

by **welsh brickie** » Tue Mar 15, 2011 4:00 pm

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

by **gags37** » Tue Mar 15, 2011 7:34 pm

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

by **andy01** » Wed Mar 16, 2011 9:18 pm

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

by **thedoctor** » Fri Oct 25, 2013 8:57 am

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.