Thompsons Water Seal

Waveydavey63

Waveydavey63

Waveydavey63

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London
Hello
The back wall of my house has a serious damp problem - it looks like water penetration through 120-year old bricks (quite a few have faces sheared off) and some dodgy pointing. The recent downpours have really made this apparent - big damp areas of plaster on inside wall.
I’d like to protect/seal the bricks ASAP, but they’re presumably saturated. Do I need to wait for them to dry out (next Spring?) before I can do this? Thompsons Water Seal claims to be breathable, but *how* breathable? The last thing I want to do is to trap a load of moisture in the brickwork!
Any expert advice gratefully received.
David
 
Don't know if this is of any help but just watched a video of skill builder doing an insulated render, but before he got that far he drilled holes externally circa 30mm from full depth of brickwork and fitted these white pegs which form some sort of DPM.

Or I've just had a really weird dream!

Edit, it wasn't a dream called dry rods, video is here https://youtu.be/96WN8AtAvNg
 
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Painting it with a sealant now won’t do anything except trap the water inside the bricks.
I’d question the use of drying plugs as well. I’ve not had any personal experience but it seems like snake oil [haven’t watched the video]
You need to find the source of the problem. Any pictures of the area outside?
 
given the age of the wall, it will likely have a slate damp proof course. This is more than adequate in most cases at preventing rising damp - unless it has failed.

However, given the description and extent of the problem it sounds like external factors are more to blame.

1) make sure any air bricks are unblocked and completely clear
2) assess the height of the ground level externally - has someone paved to the rear, is soil/foliage backed up against the rear of the house etc - making sure external ground levels are at least (more the better) two brick courses below the internal threshold (and any dpc or dpm) is vital
3) check drainage - are the gutters and down pipes leaking? Where do they discharge to and is there adequate run off away from the property?

Few ideas - ideally you need to get a look at the void beneath the floor to check for any standing water as this could also be indicative of an issue with a rising water table.

Like someone else has already said, you need to understand why it is happening to begin with before you can move forward in the most effective way.

Often the best solution is the most expensive solution but frankly I would rather fix the problem once than keep trying these stupid ‘quick fixes’ like chemical injections and drying rods.

Most damp and timber companies will come out and assess for free remember so that might be a good step.

Photos would be useful and a brief description of the construction of the wall and adjoining floor? Solid walls and floors floors? Or solid walls and timber suspended floors?

Cheers
 
Sounds like penetrating damp rather than rising damp so I’m not sure why people are recommending retrofitting a DPC, it might already have a slate one anyway.

I think yes you need to let it breathe and then you need to seal it. So, no quick fix in the mean time. Rendering it in lime would help. Rendering it in concrete could work but if damp is getting in any other way then you are sealing it in. On the inner face of the wall what is the construction? I think whichever way you go you need to allow the wall to breathe either internally or externally. Lime render both sides with breathable paint could help.
 
Thanks all. I should stress that I just need a short-term solution - I’m getting a kitchen refurb in 18 months time and replacing the wall with bifolds (and fitting a proper DPC as well). I’ll be happy with something that can fend off the damp until then
 
Waveydavey63 said:
Hello
The back wall of my house has a serious damp problem - it looks like water penetration through 120-year old bricks (quite a few have faces sheared off) and some dodgy pointing. The recent downpours have really made this apparent - big damp areas of plaster on inside wall.
I’d like to protect/seal the bricks ASAP, but they’re presumably saturated. Do I need to wait for them to dry out (next Spring?) before I can do this? Thompsons Water Seal claims to be breathable, but *how* breathable? The last thing I want to do is to trap a load of moisture in the brickwork!
Any expert advice gratefully received.
David
Click to expand...

There are a number of different products on the market to seal either side of the wall. Some of them require the bricks to be dry, some of them do not. They also have different "lifetimes" and none of them are permanent. The more you pay the longer they last. You can also use something called tanking slurry which is a cement based "paint" you buy in powdered bags and mix with water yourself. Very cheap and extremely effective. It can also be used on the inside on raw brick. It's usually coated with plaster if it's used on the inside or painted if on the outside. The paint can add additional protection, especially if it is oil based. For the inside no matter what you do, it may be necessary to apply a shellac based damp seal paint. There are plenty of options.
 
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