Wet parapet wall on conservatory...
 

I have just had a conservatory built. One end is a parapet wall with a
say 15-20 degree pitch on it.

The coping stones that sit on top of the wall have about a 30mm overhang
which is not sufficient for the water to drip onto the ground. Nor did
the builders put a drip (groove) on the underside (as specified!).

Basically, the wall is constantly wet.

Its a cavity wall and the interior side is partially below ground (about
1.5 by 1.5m). The interior of the wall is tanked with a delta membrane
which matches up to an existing delta system.

The (snagging) builder has suggested that the wall should be treated
with a proofing agent on the outside.

As the wall is sandstone and is strap pointed, I don't really think this
is the solution as this will only retain and accumulate damp inside the
cavity and will cause problems with frost damage etc etc after a few years.

Builder said to my wife that (not to me) that I didn't know what I was
talking about and that its fine if the wall is a cavity wall rather than
a solid wall. Says he does this all the time. I doubt this guy goes back
after say 10 years to see the results though.

Most of the things I have ready over the last few years advise against
proofing of stone etc etc... IMO all they need to do is get the water
off the wall.

So, who is right him or me?

TIA,

Alex.

AlexW wrote:
The coping stones that sit on top of the wall have about a 30mm overhang
which is not sufficient for the water to drip onto the ground. Nor did
the builders put a drip (groove) on the underside (as specified!).

Then you get the builders back to put a drip groove ... You haven't paid
them yet have you?

You might also want a drain (pebbles and perforated tube) along the
outside of the wall

Owain

Owain wrote:
AlexW wrote:

The coping stones that sit on top of the wall have about a 30mm
overhang which is not sufficient for the water to drip onto the
ground. Nor did the builders put a drip (groove) on the underside (as
specified!).


Then you get the builders back to put a drip groove ... You haven't paid
them yet have you?

You might also want a drain (pebbles and perforated tube) along the
outside of the wall

Owain


Thanks.

The builders will be coming back. BTW. But my contract is with the
conservatory co and there is little left to withhold :-(

mini land drain suggested, the runoff will be taken away on flags,
below which (against the wall) there is a DPM and quite a bit of 20mm
stone backfill down and some basic drainage arrangements to the end of a
land drain run which culminates in the mains drainage.

My main concern is them attempting to fob me off with water seal if
that's not appropriate?

Alex.