Advice re damp treatment

boots_babe

Hi all,

My parents moved house a couple of years ago, the survey showed damp so they had 2 companies in to review and quote.

I know that all houses show some sort of damp, and was also very wary as there seemed to be lots of dodgy damp companies just out for your money.

However, the 2 companies both reviewed well online, and both said there were abnormal damp levels and recommended a chemical damp proof course. One company mentioned insufficient under floor ventilation, but the other said this was fine. Parents went with the company who said there were no ventilation issues - on the basis that they had worked on other houses in the street and seemed to know a lot about the history of the street (previous flooding etc).

Fast forward to now and there's been a funny smell that's been getting worse over the last year. Multiple plumbers found no issue, the original damp proof people came back to review and said no damp issue.

We took up the carpet and found a very damp concrete lintel by the front door, and damp floorboards at the other end of the hall.

So mum got a different damp and timber specialist out. He's said there is a damp issue, that there is insufficient underfloor ventilation. He also suggested that as there is already a damp proof course in place, that the chemical damp proof injection that they had done when they move in was probably unnecessary.

He said he knew of the original damp company and that they rip people off and do unnecessary work. He also read the 10 year guarantee provided by the original company and said it wasn't worth the paper it's written on - which when he explained why, does seem to tally up.

So at this point I'm very confused, I don't know whether the original damp people were the cowboys and hence my parents wasted £4k on unnecessary work back then, or whether this new company is the cowboy and my parents risk wasting a further £2.5k on unnecessary work.

The new quote is for wet rot treatment, adding in underfloor ventilation and replacing the damaged floorboards. Everything the new person has said makes sense, and on asking him further questions and doing our own reading, does seem to be tally up. BUT of course we could be wrong.

I want to protect my parents and make sure they don't waste money on unnecessary work, what else should I be doing or what questions should they be asking at this point?

Many thanks.

Doozergirl

The first people were wrong.

You do not solve a damp problem without removing the source of the damp. Injecting brickwork is never going to stop wood from rotting anyway, was it?

The simple fact is that chemical injections do very little, if anything at all. It's the waterproof render that hides the damp in the wall. We're the people that see this when we're renovating houses. I've dealt with walls with three(!) injected DPCs! Like, what?!

This second person isn't selling you something you don't need, they are fixing items that need fixing.

It's imperative that you work out the exact source - it could just be a lack of sub floor ventilation, but look around the outside of the house for a potential source of water ingress.

Post photos here if you like of the outside and we'll see if there's anything additional work that will help.

boots_babe

Hi Doozergirl,

Thanks for replying. We didn't know when the first trademen were involved a couple of years ago, that any floorboards were damp. If we had then things might have ended up a bit different :-(

Unfortunately we were faced with 2 supposed experts, both well recommended, telling us opposite things. We had no way of knowing really who was right, and the reason my parents chose the one they did, is that they gave a detailed account of other houses on the same street they have worked on before, and knew all about the history of that road.

If they were the dodgy ones then clearly my parents (and us) were taken in by the fact that they seemed to know so much detail.

I'll see if I can get some photos from externally and get them posted on here, thank you.

Just as a general point in case we come across similar problems in the future in other house moves, are you saying that chemical damp proof courses are always a waste of time? Keen to make sure that we at least learn from this to hopefully be better off for any next time!

Many thanks.

Doozergirl

These people don't know they're dodgy. I think they genuinely think they're doing a good job. Even surveyors seems to think it's the right thing, but it isn't. I used to as well, but I've seen so many 'failed' DPCs and in every single case, they've never bothered to address the proper source of the damp. They simply don't understand how buildings work.

In the decade since the last DPC we installed, all we've done is locate the problem, stop it from happening, treat the building in the way should have been and was built initially (because it didn't always suffer with damp!) and have never, ever had a problem. The problem is always poor maintenance of some description.

FreeBear

Doozergirl wrote: »

The problem is nearly always poor maintenance of some description.

From time to time, damp can be traced back to sloppy building practices - For as long as I can remember, a wall in my kitchen suffered from damp. Had reason to do some work on the affected wall not long ago. On taking out a few bricks just above the DPC, I found the cavity had a pile of damp sand bridging the DPC - This sand had clearly been there from the day the house was constructed. Injecting chemicals in to the wall or applying waterproof render/plaster inside would have never cured the problem. The answer was to clean out the cavity, and replace the bricks. Also stuck an extra air brick in to improve the under floor ventilation (which was the original reason for removing bricks in the first place).

chunkytfg

FreeBear wrote: »

From time to time, damp can be traced back to sloppy building practices - For as long as I can remember, a wall in my kitchen suffered from damp. Had reason to do some work on the affected wall not long ago. On taking out a few bricks just above the DPC, I found the cavity had a pile of damp sand bridging the DPC - This sand had clearly been there from the day the house was constructed. Injecting chemicals in to the wall or applying waterproof render/plaster inside would have never cured the problem. The answer was to clean out the cavity, and replace the bricks. Also stuck an extra air brick in to improve the under floor ventilation (which was the original reason for removing bricks in the first place).

Exactly this!

If an 'expert' comes in to identify a problem or solution if they so happen to also sell the solution then run away!!

There was damp in the house I tried to buy before the one I was in.

An injected DPC was deemed to be the solution by the expert the seller got in, one quick look at the outside showed the block paving had not been dug down far enough and was way up above the DPC! The expert funnily enough didn't see that as a problem!

stuart45

Doozergirl wrote: »

These people don't know they're dodgy. I think they genuinely think they're doing a good job.

They probably do. BRE only accepted a physical DPC and chemical injection as a viable method. To be fair a lot of people think they are doing a good job, until someone comes along and points out all the cockups.