Can faulty coping stones cause major internal damp

[Maggie May]

We have a substantial problem of damp coming from balcony above. Initially , water actually dripped from light fitting in that area. Subsequently, builders have disagreed over cause, but all wanting to replace or treat the surface. None can identify leak, with all agreeing it looks sound. Quotes of between £1500 and £9000 have been submitted. A friend is convinced that it is the coping stones around the parapet walk with metal railings attached. All builders say this is not possible due to the extent of the water leaking. However, on looking at other sites it has been suggested that this could be the cause, especially as the are just ordinary stones, little overhang and perhaps no barrier beneath. I am looking to sell soon. Any advice would be appreciated .

 

[datarebal]

Pictures are pretty poor. Check seal around windows

 

[Maggie May]

The damp is mostly above the window - it is across part of ceiling , coving and wall bedside window and a little underneath window with the sill expanding and splitting due to damp.

 

[Deleted member 174758]

However, on looking at other sites it has been suggested that this could be the cause, especially as the are just ordinary stones, little overhang and perhaps no barrier beneath. I am looking to sell soon.

Not a builder/brickie, but as a joiner I have formed new balcony openings, installed doors, etc on older building conversions a few times (into double figures) and worked with other trades. The coping stones won't necessarily have much of an overhang, but every one I've seen installed went atop a DPM which was meant to reduce water ingress into the masonry. Is the drainage for the balcony adequate? Drainage inside the balcony is another issue. Is the drainage obstructed? How is the balcony waterproofed? Is it something like felt, lead, EDPM or Sarnafil beneath the deck surface and is there any damage to that?

 

[Maggie May]

Thank you so much for the reply. The balcony is about 20 years old and has a thin layer of gritty tarmac like stuff applied. The run off has been looked at around the sides , but one builder suggested changing the guttering to reduce the water being deposited there from parts of the roof. Pooling is occurring in the site of the damp underneath and there seems to be some lifting of the balcony surface coating under this area but so visible holes etc for ingress under this area.
It is really good of you to take the time to comment. How would I know if there is this barrier under the coping stones? Would the coping stones be capable of letting enough water through to cause this damage ? More pictures below. Thanks again .

 

[Mr Chibs]

Any chance you take some pics of the roof and where it meets the wall please.

 

[Maggie May]

You can see some attempts to fix by applying a coating to drain away and a little bit of diy pointing. Would some outside shots of black marks and moss outbound that area help ?

 

[Maggie May]

I am so pleased I found this site … restored my faith that there are people who want to help without money being the sole motivation.

 

[Mr Chibs]

It looks in good condition, what about another pic of the outside of the wall where the guttering comes out.

You've not had the invoice yet...

 

[Maggie May]

I have also taken more photos of damp ceiling and the ceiling light that had the water dripping through in the first instance, but hasn’t dripped since, despite the damp recurring after redecorating with damp seal paint after first little repairs we made. I also show the outside of the area near the signs of damp into the sill in same area. Signs of moss. Thanks

 

[Maggie May]

The circle visible on ceiling is from re plastering .

 

[Mr Chibs]

Well, the coping stones won't help as there is no run off on the wall side, so rain will constantly run down the wall. You can see the staining.

I was going to suggest if the issue could be condensation related, but seeing the damage inside I reckon that's unlikely.
I'd remove the downlighter and have a look in the roof, you might be able to see if it is/has been wet etc and insulation type.

I'm wondering, if it's not getting in the roof, then perhaps the cavity wall has been bridged and wetness from external brickwork is making it to the inside skin.

You need to have a good look on the roof for splits/holes etc.

I'll await someone else's comments .

Good luck

What width is the coping stone?, presume around 300mm, thinking about it, would be interesting to know how the railings are fixed to the wall... as it may be in the cavity, if there is water entry here, it's getting in between the walls. Check all bits of mortar for cracks etc.
Any holes in the metal work??

 

[datarebal]

No obvious tray in brickwork , open vertical joint on internal brick skin mitre.

 

[Maggie May]

Sorry , daraball , I don’t understand your post . I am trying to get to grips with building terms and not really succeeding !! What would that mean that you think I should do?
The width of the stones used is a tad under 300ml - not really coping stones , just slabs I am told . Another picture of railings .. no splits or damage to rail.
Have attempted to fill any crack in mortar around rail insert.

 

[Mr Chibs]

Above windows/doors there should have been a cavity tray fitted, although lots of houses have none and no problems.

On u-tube you can see them being reinstalled, it's a bit of a faff.