On Sat, 1 Sep 2012 11:21:46 -0700 (PDT), Andy Dingley wrote:

Now I've found this
http://quercus.livejournal.com/32427...43408#t1343408

Well from the bottom photo it looks like the really damp bit is the brick
of the chimeny and the immediatly adjacent bit of wall. I'm sort of
assuming that the expose bit of lath/plaster ceiling is the underside of
the bit of roof with the bodged mastic.

The cap doesn't look good it ought to over hang all the way round and
have a drip groove as well. 3 or 4" seems a bit excessive to me 1 1/2"
with the drip groove 1/2" in from the edge.

Personally the mastic is a bodge and that is where I suspect the water is
getting in. It will run down the outside of the stack and into the
rendermastic joint and behind the flashing. I think that of flashing
needs to be properly redone with the fall so water doesn't pool (if it
does) and up under the rendering skirt.

I was going to suggest that you took the stack down to below roof level
and patch the roof but I see from other pictures that would probably look
really naff.


--
Cheers
Dave.