Damp-proofing failure?

[Bloodybridget]

We had our lower ground floor damp-proofed 4 years ago with a 30 year guarantee, and now there are patches coming through again. The company charges £150 to send a surveyor to inspect the problem, which is only refundable if they accept responsibility! Has anyone had this situation; what did you do? We weren't impressed with them at the time - they drilled through a pipe and tried to deny there was a leak! - and I feel they'll be very likely to say the damp is a new problem. I don't want to throw away the money but if I don't get them back in it kind of makes the guarantee worthless.

Did they just inject? To be honest, those guarantees aren't worth the paper they are written on. You need to find the cause of the damp before stumping up for a solution.

They tanked every wall, Olivia. I will never buy a house that has rooms below ground level again!

Can you put some photos here for us to have a look at?

I have just agreed to have a silicone emulsion damp course put into my 1908 terraced house. The damp is on a wall I share with my neighbours and runs through the dining room, living room and kitchen. The work is really expensive (£2,200) and I am getting cold feet. Has anyone done this and been happy with the results? Any comments welcome.

mtfasuncion

I rather think there is a water leak under the floor. Internal walls do not usually get wet for no reason.

Have you and your neighbour got water meters? Has anyone lifted the floorboard for a look and a sniff?

Or has the wall been wet for 106 years due to the house being built on a stream?

Here are some pics, but my camera is rubbish.

@Bloodybridget. You have my sympathy. Especially after four years, when you thought you had it sorted.

@PigletJohn. Thanks for your reply. Having slept on the decision, I have just cancelled the contract. I agree I should explore the causes.

Like the idea of 106 years of damp. If it's lasted this long.....

However, I had the floorboards up when I moved in last year, as I lifted the laminate and had the original boards sanded. We had a good look at the (very simple) foundations in the process of repairing and replacing boards. There is no dry/wet rot in the underpinnings but I didn't know enough then about potential problems to check out possible causes of damp. It would be easy to get the boards up again and have a look.

I don't have a water meter and I can ask my neighbours if they have, but I doubt it. The wall by the door has patches of crystal-like deposits, and I suspect these might come from water entering from outside, as the bricks round the door need repointing. But there is a problem with whole internal wall, not just the bit at the door.

Who would you recommend for advice? A plumber, a builder, or both?

Just a thought - what is the roof like immediately above the wall dividing your home from your neighbour's? Is there a chimney stack or a valley where the rooves of the houses meet? Is it possible there is lead flashing which is out of position or has been removed? Or dodging pointing on the chimney stack. Water finds it's lowest point after all.

@wowfudge. Thanks for the comment. The roof has sunk in between the supporting joists but the tiles are in place and there shouldn't be any more movement, according to various roofers' reports. The chimney stack is not over the shared wall. And the damp is coming up from the floor, to about a metre above floor level; apparently a classic sign of rising damp.

After hunting around on other threads (Grade II listed buildings was particularly cheering), I have bought the following, in the hope of getting to understand the situation a bit more:

Old House Eco Handbook: A Practical Guide to Retrofitting for Energy-Efficiency & Sustainability Hardcover – 28 Mar 2013
by Kevin McCloud (Foreword), Roger Hunt (Author), Marianne Suhr (Author)

A plumber can detect a leaking watermain (which is very likely under the house, between where the kitchen used to be, and where the garden gate used to be, 108 years ago.

Another candidate is an underfloor radiator pipe; or a radiator; or a basin; or a long-disused pipe, in your house or next door. Waste pipes and rainwater pipes are much less likely to be under an old house (but they can still be leaking, and probably are, outside).

A water meter is good for detecting the presence of a supply leak, because the bubble never stops turning.

If it is the water supply pipe, a young person with good ears in a silent house will notice the difference when you turn the pavement stopcock on and off. It is just faint white noise so you will not notice it until it stops.

Taking up some floorboards and investigating the subfloor soil by the wet wall may be very interesting.

@PigletJohn. OK, plumber it is.

Any recommendations for a plumber in the Manchester/Stockport/Levenshulme area?

mtfasuncion, I hope you can get your problem sorted, damp is awful. I think we will ask our local builder's advice before doing anything else.

Hi Bloodybridget. Did you see that PigletJohn recommended a plumber, to try and trace where the water is coming from in the first place?

I backed out of the silicone damp course because (the little I understood of) what I read indicated the chemicals would not spread through the mortar to form a barrier if they were in contact with wet plaster. For the system to have any chance of success, the chemicals need to be in a dry area in order to act. I saw a system called Dry Zone on You Tube that involved taking off the old plaster before injecting the chemicals and then putting on new plaster board. Seems a logical way to go about it. The damp course people I talked to said no replastering was needed, but I am suspicious.

It's hard to work out what has happened to your walls. Doesn't tanking involve new plaster, etc? Has moisture broken through?

Hope you get it sorted. It's the not knowing what to do next that's the problem.

hi mtfasuncion. I don't know that a plumber would help because the damp patches are in very different places: one on the wall that divides our house from next door, one at the front of the house, one on the back wall ...
yes tanking means all the plaster taken off to a height of two or three feet, damp proof material put on, then replastering. It was a hideous process.
Perhaps we'll just move ....

Hi Bloodybridget. Sounds a nightmare. I wonder what has gone wrong.

You still thinking of bringing the company that did it back in? Surely they have to be able to explain what has happened, however incompetent they are?

Can you check what the terms of the guarantee are? Do they say on paper they will charge for visits to inspect problems?

What a worry.

damp proofing guarantees tend to say that if their treatment doesn't work, they will come and do it again.

But if it didn't work the first time....

this to me does not look like a dampproofing failure, rather a burst pipe or crack.

We have a similar issue - a corner that was damp-proofed when we bought our house 10 years ago, is very damp again. I imagine if I get the company back round they will find a way that it isn't their fault and then we'll be liable for the £150 plus new remedial works.

What I can't remember, is whether you usually pay for an initial damp survey if you are thinking of using a firm, or whetehr I'd be better going to someone else and getting a free survey (or maybe no such thing exists)?

Interested to know what you decide to do OP.

chemical injection is not much good.

Usually there is a building, plumbing or drainage problem causing the damp, which chemicals do not cure. It is always best to find and remedy the cause. Sometimes a spilling gutter or a leaking downpipe or gulley is the cause; or loose/cracked render, brickwork or pointing letting rain in.

Can I join the damp proof failure club? We had tanking done six years ago when we moved in and now one corner of the dining room is damp again. One wall joins next door, the other is the outside wall. The render looks ok, but will check it again. Outside is higher than the floors inside though, by about 50cms and I think that's maybe the cause. its obviously been damp for ages but I ignored the flaking paint as it had done that since the wall was tanked, but it doesn't look good. The original company guaranteed it for 30 years so will see what they see, not their fault I imagine.

Plumber coming round at the weekend. I like the idea of finding the cause. If I can.

Now moving on to pulling up patio decking and putting in paving. The current decking directs rain water straight at the kitchen wall. And I bought the house off an architect. All the plaster has fallen off the wall inside. The mess is hidden by the under counter fridge and washing machine, but the wall is gradually crumbling. At least I think I know what is happening here. Seems a more effective place to start than with damp courses.

@Bloodybridget. Keep going. Other threads say it's cheaper to sort out problems than to move.

Interesting about chemical damp proofing being often ineffective.

I think our problem is caused by being high up, with a corner which faces South West so is constantly lashed by rain (this is the damp corner). It's on the stairs which have a door at the bottom, so air-flow isn't great either....

I wasn't serious about moving - we put up with damp for 8 years before tanking so can live with it again! Haven't decided yet whether or not to get the company's surveyor; it would cost £150 which is not refundable unless they admit it's their work that has failed. I need to talk to DP about it again.
Houses, bah!

I now have my 'Old House Eco Handbook' and it says, 'Injected damp courses ... rarely work and are usually unnecessary, expensive and damaging. [They] are only guaranteed if combined with a hard cement tanking plaster on the inside face of the wall which traps moisture and masks the problem, leaving the wall damp and therefore thermally inefficient... Low-level dampness in solid-walled breathing structures can usually be resolved by dealing with the cause of the damp, etc.'

Could have been written by PigletJohn, who clearly knows what he is talking about.

@Bloodybridget. Anything there relevant to you?

H'm. Well, the cause of the damp in our house is having a semi-basement floor, I guess. Thanks for sharing info and I hope you can get your walls a bit drier somehow or other, mtf, southwest1 and Bramshott.