A typical phone request to me from a client starts with “We have had a survey done and it says we have [rising] damp”
At this point they don’t need to say any more, i can write the script for them……it goes….. “The report says we need a specialist damp report”
The further script i know is coming is …”the specialist company came in for free, said the damp proof course has failed and we need to spend [typically] £4,000 on having a new one put in”….”they also want to ‘hack off’ plaster to 1meter high and apply a cement render, ‘tanking slurry”.
At this point lets apply logic.
Why does the surveyor think there is damp? Because he is using an instrument that measures conductivity (i.e. electrical resistance), not moisture. You can get a reading off the scale on a million things that aren’t damp. they are however cheap, any idiot can use them (just as well) and they are covering their arses.
Now your convinced you have damp, because a surveyor has told you so, right. You look up a damp proofing company and find there are loads who come out for free. You select one as this is an expensive time for you, all the moving costs. They don’t need to convince you you have damp, you already know, that makes their job easy. They aren’t going to get a penny or even recover their cost for coming out if they tell you no you haven’t, or come up with the quick fix (see 1-4 below).
The rest, I’m sad to say, is a much repeated conclusion ….report, costly solution, you pay
Other facts you might like to know….
In older buildings a damp proof course was typically a ‘blue brick’, two courses. Make from a very hard, non porous material – it doesn’t fail !
On newer buildings they use a very think, purpose made, plastic – it doesn’t fail !
So what is the reason if you definitely have damp and the 1 in a zillion survey was correct? Ok maybe you have had some idiot remove it during a structural modification, or didn’t put one in at all, but thats minor. Most likely it either A) Build up of ground levels on the outside, 2) Blocked air bricks if suspended floor 3) Ingress from a dripping something outside 4) Trapped moisture that can’t escape (lack of ventilation) or 5) a combination of 1-4
The industry standard fix is to drill two holes in each brick in a line around your house, then inject them with a sealant. This is normally done – above – the existing damp proof course, that will be the damp proof course that hasn’t failed anyway!! Your then trapping moisture into one of these drilled bricks, a brick made of a soft porous material that was meant to get wet, then dry out naturally but now cant. It will kill this brick and there are many photos on Google of these drilled/injected bricks crumbling away. So much for expert advice !
The other fix is ‘tanking’, basically trapping moisture in to a wall by use of a simple ‘damp proof paint’, to a full waterproof slurry mix applied like plaster. OK so you won’t see damp on the outside, but its just like the drilled brick above, your trapping moisture into the brick. Its coming out of the face because its trying to get out – go to the gym in a plastic PVC coat and work out, you get the effect. Remove the cause of the damp & Ventilate. Sometimes you can’t remove the damp, its sub-floor like many Victorian properties basements. In which case ventilation is absolutely key – whatever you do, do not, do not, trap damp in.
So here is the advice.
A) look for 1-4 and judge for yourself.
B) If you must get a ‘specialist’ in, choose one that doesn’t reply on you taking his advice to get paid, i.e. a vested interest.
C) If you want, send me the report and a few photos and I’m happy to give you some free phone advice
D) Take a look around your own town and identify properties that have had brick drilling inappropriately, had PVC type paints applied to the outside and they wonder why they have damp inside, to older buildings that were designed to breath, fitted new double glazing & blocked up all holes with insulation and wonder why they have huge puddles of water on each window – then have a good laf
**This is somewhat of a personal fight-the-good-fight for me, i love buildings and i hate to see them being killed by poor maintenance or worse still, poor solutions**