Resolving Damp Problems - What to do?

[osbourd2]

We've just purchased a 1910 end of terraced property. The mortgage survey came back saying that high damp meter readings were taken and that we should seek further advice from a damp surveyor. We've had 4 or 5 damp proof surveyors around and all of them have suggested/tried to sell a chemical DPC. Only two of them noticed the abnormally high ground levels all around the exterior of the house. The readings they were getting seemed a little patchy and in the dining room (quarry tiled floor) some areas were only damp to a few inches above the skirting boards.

I'm convinced the majority of the damp problems have been caused by water ingress from the high ground levels, faulty guttering to the rear of the property and plastic sheeting being layed over quarry tiled floors.

The previous owners must have had some kind of concrete fetish, as the front and side of the house were elevated with thick slabs of concrete. We've dug out all the concrete and rubble around the front of the house and the picture shows what we've currently got. You can see the line of where the concrete was, about 2.5 bricks from the base. We've dug down and found a ledge about 4 inches wide around the bottom - you can just about see it in the picture. I was planning to put a 15 - 20 cm channel of gravel all around front the house. The wife then wants a flower bed, which I assume will be OK. We'd then either dig out further and lay the rest to either grass or slabs ensuring a downward slope from the house to the front garden wall. Will this gravel/slope help to reduce the water ingress at the front of the house or make it worse?

Thanks for any advice on this matter

 

[k2kris]

Dampness entering your building can be caused by numerous faults as I am sure your surveyors have told you. These include: no DPC, poor DPC, damaged DPC, no DPMembrane, external level higher then DPC, full cavities, leaking pipes or drains, high groound water tables, breached cavities, poor ventilation internally the list can literally be endless.

More than anything before suggesting a solution you have to find out the problem. In the reports that were provided by the Dampness Specialists what did they outline as the cause? Looking at your photo I can see two vents, I am presuming these are for the suspended timber floors or are they straight into your cavity wall? Or for a gas appliance fire?

The measures you have suggested so far seem sound. Repairing the pipes & removing structures that breach the DPC are the first measures I would undertake. A drain of descriptions externally may help if water is running towards the property. Another option would be to paint the lower sections of brick with a water proofer as they look very soft & porous from your photo.

Further to this I would wait to see if these cheaper(ish) measures resolved or at least improved the problem, however I am afraid you may have to bite the bullet with the chemical DPC.

 

[osbourd2]

No one really seems to have pin-pointed the exact cause, but I think it's a bit of everything. Certainly the dampness in the rooms with quarry tile floors was not being helped by the plastic sheeting. The dampness was travelling sideways in to the walls. We were going to try and fix the ground levels and the guttering and try and dry it out, but we've been told it could take up to a year, and it might not even fix the problem. I was trying to avoid having all the internal plaster taken out, and I'm struggling to see the benefit of a CDPC in the walls if the floor has no DPC at all. Appart from living with the damp, is there no other alternative to a chemical DPC?

 

[JayS]

From your description it sounds like the ground level is above the DPC. Alas, you got bridging...

What you are suggesting seems very reasoanble. If you can I'd lover the ground level around the outside wall 10-20 cm, leaving a small canal say 20 cm wide along the wall. Then leaving for a few months to see if it dries out or not.

A very good solution, but more expensive, is to dig out a ditch around the house and insert a vertical damp proof membrane on the outside of the house. Assuming your current DPC is intact that will stop the bridging.

The chemical damp proofing does work in same cases, but they are very keen on injecting it even though it might not be the best solution (it is actually never the best solution!) for you...

This is all tricky stuff, but really comes down to many properties being poorly built in the first place...