Am endeavouring to sell a property at the moment - well, I've accepted an offer and the buyer's valuer has just been in and done his 'stuff'.
One issue has been raised relating to a flat-roofed extension, which I converted from an existing outhouse/porch area, by enclosing the area below the existing flat roof: Before:
Bit peeved at the cement flashing issue as the property (along with all its neighbours) was built like that, there's no evidence of any deterioration of it, and no damp either. However, the cavity tray thing was new to me, and having googled a bit, it seems that by enclosing the space below the roof and converting an exterior wall to an interior one, then it's de riguer to install a cavity tray. Bit surprised Building Control never picked up on it, but there you go.
So, looks like I'm going to have to bite the bullet and do this work (especially in today's housing market). However, I'm not 100% clear what it involves. AFAICS, I need to remove the row of bricks immediately above where my black bitumen comes to, and insert a 9" DPC membrane so it curls up the inner leaf of the cavity wall - correct? And then I need to fit weep vents? Is that something like this: ? So, so you fit one of those in the vertical joint between bricks at either end of the DPC, with just the little plastic hole sticking out?
(Immediately under the DPC I suppose I should fit the lead flashing while I'm about it.)
So have I understood this correctly? Is DPC the correct material here? Any guidance mucho appreciated.
Thanks David