Rising damp ? advice/builder recommendation needed

[NMW23]

Hi. We are hoping for some advice on a possible solution to rising damp. When we bought our Victorian semi a few years ago, we were told that we have some issues with rising damp and that we should chemically damp proof most of our ground floor. We have not seen any actual signs of damp, so recently had a second opinion from an independent damp specialist.

His view, which makes more sense to us, is that the concrete that surrounds our house at the front and side of the property is too high and that it is likely covering the original damp proof layer (the concrete goes up to the air bricks). His solution is therefore to cut a narrow channel against the house to just below the original damp proof course and back-fill this with pea-shingle up to the damp proof course. I was wondering if anyone had any advice/experience about doing this work and if so, whether they could recommend any builders who have some experience with this?

Thanks!

[bonamumi]

Hi,try to give call Peter Vasco 07961403256 who done good job with our damp problm on the back of the house.

[AbDabs]

Why would you want to spend any money when you haven't actually seen any evidence of damp? There is a growing body of opinion that there is no such thing as rising damp, only dampness caused by condensation, lack of ventilation and the wrong type of wall coverings (concrete render or gypsum plaster in place of lime); it only looks like it's rising because of the pattern it causes on the colder part of the wall (heat rises, so damp air will condense at the bottom of the wall as it's the coldest part). There's also the misuse of damp meters that are only suitable for timber being used to judge dampness in plaster.

We wasted a lot of money in the past on a house as a knee jerk reaction to a surveyors report (and a condition of the mortgage). Only later when I read up about it a bit did I realise we had probably created more of a potential problem than we had resolved.

That said, your specialist's suggestion of removing some of the concrete sounds like a good idea if you do start to have real damp problems but, if it was me, I'd wait until you start to see damp (if you ever do).

There's a book "The rising Damp Myth" by Jeff Howell that might be worth reading. You can buy it from RICS books (the Royal Institution of Chartered Surveyors bookshop)

[mancity68]

I think what he is describing digging is a 'French drain'. We have one round much of our house for same reason. Ground level too close to air bricks. It's a well practised technique and, whilst I have some sympathy with the 'wait til you see it' approach, sometimes that's too late....

[Sandberg1860]

Agreed with AbDabs.

We provide damp survey services and frankly we only get involved when there has actually been a problem. Even if we attend site and see a damp stain somewhere, the question has to be raised as to whether it is 'historic'. Seems a little premature to suggest issues with construction before getting visual evidence.

I'd tread carefully.

The surveyor you mentioned appears to have noted a possible bridging of the damp proof course, which occurs if construction materials block the damp proof course and thus allows water to become trapped and soak in to the construction. In order to determine that, however, you would need to find out exactly where the DPC lies.

Another thing i'd be weary of is advice from some damp proof contractors, as some are really just out to make a fast buck.

[ed_pete]

Second mancity68, we used to have an old single storey extension at the back of our house and solved the damp issues with a french drain which was exactly as you describe. Sorry I can be of any help regarding builders, our was done by the landscaping company that laid a patio.

[katanita]

I had something similar done by Dampworks http://www.dampworks.com/, who will do a free survey and estimate. Was pretty pleased with the work they did and (so far, fingers crossed) have had no recurrence of the damp issues. I'm no expert on damp, but would say that if you can do something external and simple like a french drain to prevent a problem before it starts, it could potentially save much bigger works to remove damp plaster and redecorate whole rooms again later. Which is no fun, believe me.

[Weathergirl]

Just wanted to crash this thread to ask if there were any more recommendations for someone who could deal with some rising damp?

It's a builder minefield out there....