Rising Damp

[fidom]

I suspected that the bottom of some of my internal walls were damp and have now confirmed this using a cheap Lidl moisture meter. The outside walls have a painted on damp course but the internal ones have no damp course at all. I remember when I bought mt first house in 1981 the mortgage lender required me to strip the plaster off the bottom 2 feet or so from the walls, paint the brickwork with bitumen paint then re-plaster. Should I do the same in this case or is there a more modern way to fix this? The walls are about 11" thick and built with solid clay bricks (the old Hungarian bricks are bigger than UK ones).

 

[foxhole]

Damp meter is for timber cannot penetrate deep enough to detect in brickwork, if it recorded moisture it would be condensation at surface.
Better to find out whats causing the damp, leaking pipework, drains, gutters, raise exterior ground level? etc etc.

 

[fidom]

As I said, the damp is in the internal walls so none of the causes you mention apply. There are pipes buried in walls but not in the areas that are damp. I thought moisture meters were what surveyors used to check for damp.

 

[ree]

A "Moisture Meter" can be used to test a variety of materials - wood, plaster, mortar etc. The MM works on the principle of electrical resistance between the two points of the two prongs. Moisture in a material causes resistance. A lot of moisture means a higher resistance reading on the MM. High MM readings indicate the presence of "damp" but they do not indicate the cause. Experience does that.

OP,

painting the brickwork with bitumen will not create a DPC. Bitumen provides a form of water proofing that can create condensation on interior plaster, and will simply force any rising or penetrating damp higher up the wall. Hence, bitumen will often cause more problems than it solves.

It might be that the damp you notice is from a solid floor or, as above, from condensation.

If you are serious, then perhaps post pics of the exterior and the interior?

 

[fidom]

There is not much to see now, just discolouring of the white painted walls. The old plaster was falling off and some of the bricks were crumbling, as though damaged by frost. I re-pointed the brickwork, re-plastered and eventually painted. This was over a year ago but the paint quickly goes yellow however many times I paint it. I have wondered about dry lining using foil backed plasterboard.

 

[Burnerman]

Internal walls need a DPC just as much as the external walls.....is it possible to have an injected DPC applied - preferably below the floor level if its a suspended timber floor?
John