Does this parapet look ok?

[fosterdog]

I've been getting damp smells from the party wall under this parapet after it rains for the past year or so.

Most of the weather hits my neighbours' rendered side rather than mine. The dark patches / streaks on my neighbours' side suggest to me that quite a bit of water comes through the joints between the coping stones and that there may be a more extensive problem in the top half of their side of the parapet where the render is all dark coloured - potentially from a gap at the peak of the coping letting water behind the render?

What do you think?

(I made a previous post about this but it was stupidly long so I don't think anyone read it and I can't blame them. If anyone wants the details, the other post is here: https://www.periodproperty.co.uk/forum/viewtopic.php?f=1&t=17001)

 

[Feltwell]

Well, it's certainly not the neatest or most professional looking leadwork on either side, but as to if it's doing it's job or not there's no way to tell without a close inspection - but I'd certainly be suspicious of it. It doesn't look to have been done well.

Rendering is usually done in these circumstances as a "cheap & quick" fix to cover the real problem that the pointing requires renewal. Rendering is not a good idea I'd suggest, better to repoint the parapet on your side if needed, in lime.

Without access you're really just guessing. Once you've got scaffolding up you'll see a lot more. If the coping is not well pointed up and is letting water in that will be a problem, similarly if it's not throwing the water clear and it's running back under the edges of the coping and soaking into the wall. There *should* be a drip stop under the coping, on the neighbour's side it's possible the render has covered it.

But I'm afraid the only real way to determine problems is to get up there.

 

[RBailey]

Good use for a drone, do you know anybody with one who could do a quick fly around?

 

[fosterdog]

Thanks for the replies - really appreciated. Might be a couple of days before I can respond properly as my partner's just gone into labour!

 

[Blueyes]

I had similar but worse and ended up reinstating and rerendering my parapet wall last year. Scaffold right up to the roof so you could step onto it then took two of us two days to completely remove coping stones and hack off old render, relay existing coping stones with a decent bricklaying dpc (not a cheapo plastic one), new lead and two coats of render. Some houses have lead all the way up instead of render but uncommon in my area and seemed an expensive way to go. Also replaced the old tile as well whilst we were up there, hard work, especially in November.

Trouble will be knowing whats underneath that render and even under those coping stones, I had a right old crumbly mess of loose brickwork, plants and mud under mine!

Grab a pair of binoculars or get some roofers to take some photos for you if youre getting quotes. Lime render is a good shout if you can do it before the depths of winter. Having a scaffold right up to the roof makes a massive difference in lifting off heavy coping stones.

 

[DJH]

I guess the only answer to your question fosterdog is no.

Looking from the top of the parapet and working down I agree that a suitable dpc should be fitted under the water tabling or coping stones, and the opportunity taken to cut a drip groove under the lip edge of the stones. This should help prevent wind driven rainwater from tracking back under the dpc and wetting the brickwork.

The existing lead has been turned into a stone saw cut groove by the looks of it. I reckon the more traditional step flashing would both look better and do a better job of keeping out rain. Each turn of lead into the mortar should have an upturn which can then be fixed with stainless steel screws and washers.

The existing lead look as though it is not dressed enough into the corrugation of the tiles or dressed tightly over the leading edge. A perfect scenario for wind driven rain to penetrate both the wall and substrate. Because of the low profile of those tiles I wouldn't use soakers in the refit but a secret gutter against the wall where the step flashing will extend down over the upstand of the gutter. The tiles will then extend over the gutter butting up to the wall and Bob's your uncle..