Damp problems and the PCA

[jrpfinch]

I've just moved into a Victorian House near Denmark Hill. There is a damp problem in the corner of the lower ground floor. The damp source is not immediately obvious.

I've spoken to a number of damp specialists, including "independent" damp surveyors, all of whom appear to be members of the Property Care Association ('PCA'). I'm not convinced by members of the PCA.

The previous homeowner had to pay a PCA member ?50(!) to have a damp guarantee transferred to our name. After taking the money, the PCA member got our address wrong and put a PO Box address and non-existent mobile phone number on the guarantee. Another PCA member emailed me to say "We have signed up to a code of ethics that prevents us getting involved in potential guarantee claims against other contractors".

See where I'm going here?

I'm looking for a trusted non-PCA professional (architect/structural engineer?) who I can pay to examine our house and say something along the lines of "Put an airbrick here/drain there/dehumidifier here/dig out that soil/you have a leaky pipe". Normal buildings surveyors don't appear to be much use beyond running along a skirting board with a moisture meter.

I'd be grateful for your thoughts and advice.

[Monkey]

The damp proofing industry is very dodgy. We saw lots of very unreliable people before coming across timberwise. They were great from start to finish! Www.timberwise.co.uk.

[Fuschia]

http://conversation.which.co.uk/energy-home/damp-proofing-investigation-rising-damp-wall-condensation/

[Marmora Man]

Or here

http://www.askjeff.co.uk/rising_damp.html

[jrpfinch]

Thank you for the suggestions so far.

Jeff looks great. I may buy his book. I am looking for a DPC skeptic like him.

Please don't take this criticism personally:

Timberwise seem to be heavy on the damp-proofing and are members of the PCA. Timberwise may well be a great firm, but I'm skeptical.

The Which? conversation appears to have been taken over by somebody who continually recommends PCA members.

As far as I can tell PCA = DPC salespeople/PR. The hurdle to joining the PCA does not appear to be high in terms of professionalism or workmanship (see my example above).

[jrpfinch]

Timberwise come bottom of the Which? survey of damp experts.

Perhaps I'll try Rentokil or Peter Cox, although neither of those were perfect either.

[EPB]

Send a pm to Hawley - he can put you on to a really excellent (and totally independent) damp expert.

PS. a useful rule of thumb: if someone offers 'free advice' it's probably because they're going to try to sell you something. Truly independent experts will charge for their services.

[jrpfinch]

Thank you EPB. That's true.

Truly independent experts will charge.

Unfortunately not all experts who charge are truly independent.

[EPB]

Hawley's chap seems very good, and totally independent. I'd try him, if I were you.

[alice]

there's only 2 kinds of damp rising [never much higher than 70cmish] and penetrating - doesnt need a lot of cash to work out which

[jrpfinch]

I'll try to keep an open mind, but looking at the other threads, Hawley seems to recommend these people:

independentspecialistsurveys.co.uk

They are yet another dreaded PCA-accredited firm. The links in their "Expert Witnesses" section all refer to people who trash Jeff Howells. Interesting. Sorry if I'm starting to sound like a paranoid conspiracy theorist.

I think I'm really just looking for a decent builder. Surely a builder can identify a lack of ventilation/leaky drainpipe/high soil line or whatever the damp source is.

I'd like to eliminate the damp source, stick in a dehumidifier for a week or two, repaint and wait to see what happens.

I'm not interested in chemical damp proof coursing or spurious testing.

[EPB]

Alice - you forgot to mention the third cause of damp (particularly prevalent in under-ventilated and double-glazed homes): condensation.

[sedm]

We've recently had a damp proof course done on a converted Victorian flat by Kenwood, who I wouldn't necessarily recommend.

The one thing they did discover that may be of use to you, is that there were two blocked in chimneys which hadn't been properly vented. I wouldn't have realised they were there, but they were located quite close to the two worst damp patches. They are easy to fix because you just have to put vents in the top and bottom of the chimneys, and I think probably quite prevalent in Victorian houses.

[jrpfinch]

Thanks sedm. This is the problem with damp-proofing companies. They put in DPCs, whatever the problem.

I think my damp source is just inadequate ventilation. Possible blocked chimney and airbrick.

Does anyone know what the flooring of a Victorian ground floor sits on? Is it likely to be be floorboards on joists with a cavity? What would be below the cavity? I know nothing about building and am trying to find pictures on Google.

[KidKruger]

Below the cavity is the ground (what were you expecting ?!).

The height of cavity can vary.

[jrpfinch]

Concrete? Gravel? Some sort of membrane? I don't know. Like I say, not an expert.

[Townleygreen]

It will be a suspended wooden floor (floorboards) mounted on joists with a gap (supplied with vents/air bricks) before the ground.

[jrpfinch]

I think I have the definitive answer from a structural engineer:

There are 4 causes of dampness:

1) external ground levels being higher than the internal floor level, so moisture in the ground can pass directly through the wall. Best remedy: lower external ground levels to at least 150mm below internal floor levels.

2) defective rainwater goods (blocked or broken gutters or with incorrect falls, or downpipes with open joints, blockages or cracks). Best remedy: replace.

3) leaking water pipes: incoming mains water, central heating pipes etc. Remedy: find the leak and cure it.

4) condensation. Best remedy: improve ventilation (especially under-floor), add heating, insulate, avoid sources of water like boiling water from cooking or baths near cold surfaces

[jrpfinch]

Here is a damp expert who specifically distances himself from the PCA:

http://www.dampnessdiagnosis.com/DDCContactUs.htm

Will report back if I decide to use them.

[alice]

and another takes same line as one above

www.ukdamp.co.uk/index.php

[jrpfinch]

-- moved topic --

[jrpfinch]

^^^^^^^^ err no they don't. They are members of the PCA.

[alice]

websites couldve been written by same person - summarized 'chemical dpc are pointless'

but back to orig post problem - assuming ground level is above floor level [you mention a lowerground floor]

simple solution could be - dig a trench to below floor level 10/15cm wide fill with shingle - not pea but the 30-40mm stuff - this enables air to circulate without being tech heavy. I've done it - it works. but i'll bow out now.

[jrpfinch]

Thank you Alice. Sorry for my snappy response.

That sounds like a good idea. One other house on the street appears to have done it.

A few others appear to have a 10cm black inset surface with an overhanging lip to divert rainwater.

[AnnieT]

Hi there,

Joining this conversation a bit late but have the same thoughts about expensive damp specialist jobs. We used kenwood at our last home and the damp returned and when we asked about it being sorted under the guarantee of course they had every reason to get out if it.

It looks like we have rising damp just behind our front door. Assured preservations have quoted us ?600 to fix- by injecting chemicals and re-plastering but I'm wondering too if there is another way we can solve this and one that is much less expensive!

Jpr finch or others, please let me know who you have used and if you would recommend them?

Many thanks!