damp removal from solid walls

[ronkt]

I have an Edwardian house 1903 with solid exterior walls three bricks thick. The walls are rendered with cement and due to cracks from ivy removal

20 years ago the cracks were filled in with strips of Marglass pasted on with a water based bitumen base coat,a dulux product l think. the walls were then painted fully with the bitumen base coat allowed 4 weeks to dry then injected with silicon and over painted with Dulux Weathershield paint. recently l have noticed damp and mould inside the house on this wall ,l have moved the radiator to this wall to help keep dry. l beleive that the rainwater is getting past the silicon through minute pockets in the wall.

would it help if l installed air bricks in a line along the area of damp to help dry out the outside,and leave a gap behind the air bricksto facilitate damp collection. re-rendering will cost in excess of =A310k

[The Natural Philosopher]

As with all damp, you have to understand what is causing it before=20 treating it, or you have a 50-50 chance of making it worse.

My GUESS is you have a condensation problem, rather than penetrating=20 damp. You need to supply more context, like where the damp is, which way =

the wall faces, and so on before an accurate diagnosis can be made.

Pictures help a lot too.

[ronkt]

The front of house faces East and the wall is south facing receiving the rain on the first 12 feet then l have a porch followed by a large window.The mould shows on the inside and my friendly plasterer reckons the silicon is stopping the moisture evaporating out of the wall.he suggested putting a row of air bricks along the bottom at 1 mtr intervals as a way of drying the wall. l would dry line but l have some really good original plaster mouldings and it would look odd if l only did one wall.the inside wall has been coated with a damp proofing paint and gloss paint over that then wallpapered. l first noticed this when l removed a large display case that had stood against the wall for 16 years,6ft x 8ft,the wallpaper was peeling off and was black behind.,l now have a radiator with 4500 BTU on this wall as a means of drying.

[RubberBiker]

That alone may be your source of damp. The uninsulated wall, along with large furniture, leading to a pocket of cold stagnant air - conditions which might allow household moisture to keep condensing in the same location.

Sounds like you may have already fixed the problem by moving the furniture an installing the rad.

Unless there's significant damp in the underfloor void, I can't see how airbricks will help much through solid masonry walls.

Is it possible that ground levels outside have bridged the dampcourse?

Is it possible to lift a floorboard and check the underfloor void?

BTW - you're typing "L" where you mean "I"

[george (dicegeorge)]

Give it a few months and see if it gets better or if it gets worse only n rainy weather etc

[stan]

[The Natural Philosopher]

Defintely agree on that one. Unless its obvious, watch and wait.

[Clot]

I read your quest prior to future answers but had the same thought as your repondents. You may have resolved your issue.