How can I stop damp coming through wall?

[Gary111]

Hi John, any idea what I can do regarding no visible DPC around most of the house please?

It has been re pointed.

I have checked the water meter and the bubble isn't moving.

 

[JohnD]

I'd be surprised if there wasn't one. The brickwork and iron waste pipes suggest it is not too old. Have a look under and beside the doorstep.

Typically it would be immediately below, or above, the original airbricks. It may have been pointed over. Have a look at similar neighbouring houses for clues.

I still suspect the source of water is drains leakage, if your water meter shows no sign of a pipe leak.

The ground hear thar airbrick looks wet, and there is some kind of drain beside it. Can you lift some pavers and look for wet ground?

 

[noseall]

Hi, I have a patch of around 1x 2 feet of flakng paint at the side of an old disused chimney breast.

I am wondering what's the easiest way to patch it up?

I have some mapei shower paint on membrane, I wondered about hacking that part of plaster and painting the membrane on the bricks before re plastering?

Alternatively fixing a new piece of plasterboard over the whole side of the chimney?
I don't want any damp to soak through dot and dab fixing though.

Any ideas please?

Look at hygroscopic salts contamination. Look towards a blocking render internally using sand /cement render with SBR slurry and waterproofing add-mixture in the render.

 

[Gary111]

If chemical dpc doesn't work is there some way of retro fitting a dpc by raking the mortar out brick by brick?

 

[robinbanks]

Cor, that's quite the undertaking - it'd probably be easier to remove the chimney; in this day and age of sky high prices, who wants a gaping hole to the world letting their paid-for heat out?

 

[lostinthelight]

You may not have a damp course as the bond on parts suggest solid wall which were probably built using lime mortar.
Not suggesting you go down the route I did but interesting reading :

Managing damp problems in old buildings

wasted money on PCA chemical damp proofing, damp plaster, mouldy walls, peeling wallpaper, crumbling brick and stone, rotting timber, damp proof old house, damp problems, rising damp solution, condensation on wall, damp proofing stone walls, sealing damp internal wall, how to stop rising damp fraud

www.heritage-house.org

 

[JohnD]

DPC became mandatory in London in 1875. Some more backward areas were later, but the building shown looks to me like no earlier than 1930, and is not rural. Lime mortar was still being used in the 1940s, typically with slate DPC and sometimes with bitumen products.

I would be surprised if it had been built without a DPC.

 

[Gary111]

Hi John, Could it be that the black ash mortar has been pointed with cement and that is stopping it breathing so much?

 

[JohnD]

Cement mortar does not create water, though it can reduce evaporation.

And I still suspect that the excessive water is caused by leaks.

 

[JohnD]

...The main visible areas of damp are in the bathroom and round the disused chimney area.
Also the bedroom....

Visible damp in a bathroom is most often leaks (if near the floor) or condensation (if up the external wall).
A damp concrete floor is often leak-related.

 

[lostinthelight]

Cement mortar does not create water, though it can reduce evaporation.

And I still suspect that the excessive water is caused by leaks.

Excessive accumulation water can also be a result of a buildup due to an inability to evaporate like the building may have designed to do due to cement products or impervious coatings blocking the way.

 

[JohnD]

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