Is This a Stupid Idea?

[Nick]

I know little to nothing about brickwork so would appreciate if someone could tell me if I'm miles off with this thinking.

 

Currently looking at a 225mm solid brick built (uninsulated) building with three floors plus basement. Would need to insulate it down the line so wanting to make sure the construction is sound.

 

The original brickwork has been painted over - overall the condition doesn't look too bad considering the age. At basement level there are a few spalled bricks and a lot of efflorescence, but this is only in the vertical runs of brick where there are no windows or stone cills (i.e. the sections where rainwater is running down all four floors uninterrupted and soaking the basement brick from the outside).

 

The areas of brick under the stone cills at basement level look lovely and dry in all cases, so my thinking is that if I were to get some kind of drip edge profile installed in the mortar bed on every floor at cill level and screw it to the underside of the stone cills for support , it would shed rainwater away from the brickwork on the floor below and stop it running down onto the basement where it is creating issues.

 

Other than the fact it probably won't look the best, is this a done thing / practical in any way? If not, are there better solutions out there? Am wary of trying to waterproof the brick from the outside without first doing everything I can to keep water away from it.

[Bonner]

No idea is stupid, not considering something is ... however what you are proposing could do more damage than good. As long as the roof and guttering is sound, the walls should not get soaked. Also, pointing helps to shed rain, is that in good condition? Are you sure the damp at basement level is not rising? What is the ground level outside compared the inside? Any signs of excessively wet ground (drainage issues)? Avoid waterproofing the brick wall outside, it is likely to trap moisture and potentially blow the brick face. This maybe what the paint has done. Are there any similar aged buildings nearby? They could give a clue if it is a common or isolated issue.

[markc]

As above, water running down a large well pointed wall isn’t a problem. More likely that the ground level has been raised, maybe concrete etc. That prevents water from draining away,  some pics would help.

[Nick]

Thanks both. Couple of photos that I happened to grab below. The run marks where the paint has washed off show the difference between sheltered and exposed areas I was talking about. Hard to tell under the paint but pointing condition looks reasonable-ish to me? No similar buildings nearby unfortunately - all newer construction.

 

Thinking about it now and looking back at photos, the window openings are keeping the brickwork directly above them isolated from the ground so as well as rain, it makes sense that they'd also be better protected from damp as you've suggested. Assuming it is damp (or damp but with rainwater making it worse), is there anything that can be done? 

 

Main concern is obviously if we have to insulate the walls internally, it will only make moisture issues with the brickwork worse. Can get spalled bricks changed and the wall repointed if need be, but would I be looking at improving the drainage away from the building and/or tanking the basement walls to sort it out longer term?

 

[markc]

Looking at the top pic I would say the L/H side is vegetation damage, yes the couloir has been washed out by water running down the face but that’s understandable.

the soil against the wall in bottom pic will be keeping the walls wet.

[saveasteading]

Can you have a poke/scrape at the wall and see if any paint flakes off,

then report back with what type of paint you think it might be?

 

basically wondering whether the paint is snowcem type (porous masonry paint) or gloss or other waterproof type.

Or maybe more than one layer. I think brush marks are visible in places.

[Lorenz]

Looks like an old problem and they have used paint to try and make it look better.

 

Sadly this chap past away a couple of years back, but his site is a good place to start in understanding things; Damp Wall & Wet Cellar - Rising Damp Scam, Saltpeter & Capillarity in Old Buildings - a Hoax of Moisture & Salts (konrad-fischer-info.de)

 

[Nick]

Thanks for the replies and resources. Next time I'm there I'll take some more detailed photos and scrape at a few bits to see what exactly we're dealing with.

 

Have been reading up on solutions and in this case there's no real access to most of the basement walls from outside. Seems pointless tanking from inside - would still leave the brickwork wet and it's not habitable space. No real damp showing through inside anyway.

 

Anything else that can be done given the lack of access or is this just something you have to live with and hope it doesn't become a serious problem?

[Mr Punter]

Internal type C drained cavity membrane with sump and pump will work 100%.  You will lose a bit of internal space but it will be completely dry.

[Nick]

26 minutes ago, Mr Punter said:

Internal type C drained cavity membrane with sump and pump will work 100%.  You will lose a bit of internal space but it will be completely dry.

 

Thanks, looks good! Will it actually keep the external wall dry in any way though, or just remove the water once it's already ingressed into the basement?

[markc]

7 hours ago, Nick said:

 

Thanks, looks good! Will it actually keep the external wall dry in any way though, or just remove the water once it's already ingressed into the basement?

Wall remains wet, this just gets the water back out of the house and gives you a dry inner wall finish

[Nick]

Cheers. The funny thing is the inner wall really doesn't seem that bad. Will have a much more detailed look next time I'm there, but my main concern at the moment is that the brickwork will stay soaked on the outside with all the earth against it and develop more issues over time.

[Lorenz]

If you look at the link I sent it should explain somewhere.

There will be more activity on the outside wall, so more damage.