Solving a damp issue in a rubble built wall.

ando2891

I have a damp problem in a rubble built cottage wall that I’m looking for opinions on how to sort out. The cottage was renovated in the last 6 years and During this the old floor was removed and re-screeded and also lowered by 3 to 4 inches. This left a gap in the plaster around the bottom of the walls right around the room, someone in they’re infinite wisdom filled this with a gypsum based plaster, which has soaked moisture from the wall.
I’ve removed the gypsum plaster as you can see in the pics which has exposed the stone in the wall but also large cavities under the stones can be seen, I’m looking suggestions as to where to go from here? Pour sand and cement with waterproofer into the wall now to stabilise it then plaster with a sand and cement? There’s places I can get my hand into and touch the subsoil the wall is built on!

All suggestions welcome!!! Thanks!

BryanF

Research Electroosmosis

riemann

ando2891 wrote: »

I have a damp problem in a rubble built cottage wall that I’m looking for opinions on how to sort out. The cottage was renovated in the last 6 years and During this the old floor was removed and re-screeded and also lowered by 3 to 4 inches. This left a gap in the plaster around the bottom of the walls right around the room, someone in they’re infinite wisdom filled this with a gypsum based plaster, which has soaked moisture from the wall.
I’ve removed the gypsum plaster as you can see in the pics which has exposed the stone in the wall but also large cavities under the stones can be seen, I’m looking suggestions as to where to go from here? Pour sand and cement with waterproofer into the wall now to stabilise it then plaster with a sand and cement? There’s places I can get my hand into and touch the subsoil the wall is built on!

All suggestions welcome!!! Thanks!

This is a good example of where you will be best served working with your building, instead of trying to fight it.

If you have rising damp, which it would appear given the wall doesn't have a DPC, then unfortunately trying to trap this damp within the wall will not work in the long term. It will always find its way out through the path of least resistance.

Cement or concrete should not be used as they will prevent the wall from breathing. A lime based mortar will allow you to fill the holes in the wall with suitable stone, which is necessary from a structural point of view.

You could then render the wall, again with a breathable product like NHL. Followed by a coat of breathable paint.

The most important thing to remember is the damp is going to keep coming up, it is best to let it do this and ventilate your rooms using windows or a dehumidifier. Trapping it in the wall may work short term but will cause it to find another path and possibly provide conditions for mould or other unpleasant matter to materialise.

Electroosmosis is certainly not suitable for one wall of a domestic dwelling, and generally speaking not recommended by specialists.

gctest50

Option 1 :

Bulldoze it and use the rubble ro build a nice wall

Option 2 :

strip off the plaster inside and build an insulated stud wall ( w/membrane ) out of treated timber
Leave a nice gap for air behind it
Ventilate it from outside
You don't want warm damp air from inside hitting it
Repurpose an mvrh unit or something in the attic to suck air from the gap when it's an advantage

Lots of other options

Bulldozing it and rebuild it with a real life living breathing engineer is best though

BryanF

OP please don’t post the same thread in more than one forum

Please advice the mods which forum you want the thread open in