What to do about damp

JuzaMum

Hi, I have lived in my house many years and recently have found two damp patches in corners of the house. The walls felt very wet and had black mould on when I found them. Obviously I have cleaned off the mould. The damp comes up from behind the skirting board and goes about 6" up the wall. One corner has nothing on the other side - just bare brick with soil below the damp course level. The other corner has the corner of a retaining wall touching it. The retaining wall has a damp course built in between the soil and the house. How do I go about finding the source of my problem? I wonder if the heavy rainfall in winter has been a contributing factor. Do I buy a damp meter and keep an eye on it? Any suggestions and advice gratefully received.

RelievedSheff

Have any leaves or mud etc built up between the house and the retaining wall which could be holding moisture there?

Doozergirl

Photos will help 🙂

JuzaMum

I popped out to take some pictures (still not sure where to host them yet). Soil is below damp course on one side, round the corner running along the wall is block paving slightly above the damp course. The block paving has been there many years so why it's a problem now I don't know but I guess that is it? I guess I will need to get that taken up and laid at a lower level?

Doozergirl

You can post pictures directly to the forum now. 

There's a picture button in the editing box.  

FreeBear

JuzaMum said: I guess I will need to get that taken up and laid at a lower level?

Have a look at "French Drains".

With all the rain we had last month, bouncing off hard paving could quite easily have saturated the wall. By all means get a damp meter, but be aware that they only give an indication of moisture levels in untreated wood. On plaster, painted timber, and brickwork, salts & metals will affect the readings by a significant margin.

RelievedSheff

Is the damp proof course in tact and undamaged in the damp areas?

With all of the wet weather we have had this winter (and the high groundwater we have here) you could visibly see the dampness in the bricks on all of the new build properties on our estate up to the damp proof course. It was very obvious which plots have issues with the damp proof courses as the damp tracked further up the walls in an inverted V shape. We didn't see any issues on our plot but we did see a big problem on the plot opposite which we very nearly bought instead!!

The block paving being above the damp proof course most certainly won't be helping matters that wants relaying as soon as possible.

JuzaMum

Thanks for the responses. The damp course is slate (the house was built 115 years ago). On two sides of the house it has some kind of render covering the brick below the damp course coming up to the level of it. You can see the top of it behind the grass. As the house is on a hill at the front the ground level is well below the damp course but at the back of the house the ground level is higher. The level of the block paving gets slightly higher as it goes beyond the gas pipe.

RelievedSheff

Is the damp in an area where the ground level is above the DPC?

JuzaMum

Yes the ground level is above the damp course - I hadn't realised as it is only above on one side of a corner. It is surprising it has only become a problem recently. 

Petriix

Looks like soft brick. Has it had cavity wall insulation added recently? It can bridge the cavity allowing water to penetrate the inner wall.