Damp in earth bearing wall

Atkinsda

hello, after some online advice and potential damp wall diagnosis! We have a three story house and the lower ground floor is built into a hill/slope. This means one wall is earth bearing on the lower ground floor. The property is about 50 years old and we’ve been here for 2 years. After all the recent rain we noticed that the earth bearing wall plaster was wet and the skirts were discoloured due to damp, even the laminate flooring has started to warp due to moisture. The damp goes above our plug sockets - the damp is from the floor up and at its highest, is about 1.5 feet.
We have a very kind friend who suspected it was rising damp and we’ve had the dry rods injected into the skirts to treat.
However, a month on, with more persistent rain the damp is coming back! You can see water marks where the plaster has dried but there is still some damp coming through.
There is no damp anywhere else, just at the base of the wall. As far as I’m aware, there are no pipes or drains behind this wall, just earth.
Should I wait until summer to see if it thoroughly dries out or should I call a company in to check it? I’ve not removed the plaster yet as was gonna wait to see if the problems resolved before getting a plasterer in.
Thanks in advance!

G_M

Atkinsda wrote: »

....We have a three story house and the lower ground floor is built into a hill/slope. This means one wall is earth bearing on the lower ground floor. ....we noticed that the earth bearing wall plaster was wet and the skirts were discoloured due to damp, even the laminate flooring has started to warp due to moisture. The damp goes above our plug sockets - the damp is from the floor up and at its highest, is about 1.5 feet.
We have a very kind friend who suspected it was rising damp
He may be kind, but he's wrong. It's penetrating damp, not rising!

and we’ve had the dry rods injected into the skirts to treat.
So that stops damp rising up. But if the other side of the wall is pressed against earth... well, the damp in the earh is penetrating inwards.

However, a month on, with more persistent rain the damp is coming back! You can see water marks where the plaster has dried but there is still some damp coming through. Not surprised.
There is no damp anywhere else, just at the base of the wall. As far as I’m aware, there are no pipes or drains behind this wall, just earth. And the earth,of course, is bone dry. Not!
Should I wait until summer to see if it thoroughly dries out or should I call a company in to check it? I’ve not removed the plaster yet as was gonna wait to see if the problems resolved before getting a plasterer in.
Thanks in advance!

It may dry out to a greater or lesser extent after a long hot summer. But the issue will recur next winter, or indeed if there are wet summers. If the earth gets wet and there's nothing to prevent that dampness penetraing through the wall, the problem will recur.


You need either a physical or chemical barrier to prevent the damp from penetrating.


Pay a specialist, independant, damp surveyor to advise you. Not a salesman [STRIKE]surveyor [/STRIKE]from a damp proofing company who will just recomend whatever treatment his company specialises in.

FreeBear

G_M wrote: »

You need either a physical or chemical barrier to prevent the damp from penetrating.

Pay a specialist, independant, damp surveyor to advise you. Not a salesman [STRIKE]surveyor [/STRIKE]from a damp proofing company who will just recomend whatever treatment his company specialises in.

By the sounds of it, there may be problems with the tanking on the external wall. I suspect that the earth around the house will need excavating and a waterproof membrane fixed to the wall. Not going to be a cheap job, but tackling it from the outside will be a lot better than slapping waterproof render on the inside walls.

Oh, and those magic "damp proofing" rods that you spent good money on - They are a waste of time. They are supposed to seep in to the brick & mortar joints, and dry to give a barrier to moisture. But if the wall is permanently damp, how do you suppose the treated areas will dry....

Atkinsda

Thanks for both those replies.
If it was penetrating damp would the damp not be on the whole wall? It’s just at the bottom. The whole wall is earth bearing and has our lounge on top of it on the next floor up as the property is built into a hill.

Atkinsda

By the sounds of it, there may be problems with the tanking on the external wall. I suspect that the earth around the house will need excavating and a waterproof membrane fixed to the wall. Not going to be a cheap job, but tackling it from the outside will be a lot better than slapping waterproof render on the inside walls.

The other side of the wall as it has two stories on top of it so be set difficult to excavate and treat externally. my only option would be to address in from the internal side I’m guessing?

I’ll call a range of companies for quotes too - thanks

DavidFx

Atkinsda wrote: »

If it was penetrating damp would the damp not be on the whole wall? It’s just at the bottom.

It's almost certainly a cavity wall. The tanking has failed on the outer skin so the water is filling up the cavity. Under 'normal' conditions, the water level in the cavity is below the inner DPC (it is draining faster than it is filling) but with the heavier rain the level has now breached it.

Mistral001

It is important that there is free-draining material such as stones on the outside of the wall and there is a drainage pipe which drains the water away to lower land or a storm drain. If that free-draining material and pipe is not there or it is clogged, then water will build up on the outside of the wall and the wall effectively becomes a dam rather than a earth retaining wall.

Whatever you do I would get the back of the wall examined as just doing the work from inside could just be a sticking plaster that will not last very long.

Atkinsda

Appreciate all your comments - I’ve got someone coming to look tomorrow. My only concern is that I can’t get to the external side of the wall as this is underground with a building on top of it.
I’ll see what tomorrow’s chap says and then maybe get a few more quotes/diagnostics by way of validation.