Rising damp - is the surveyor always right ?

Hi Dogz.

Do you have rising damp? Maybe. Maybe not. Sorry - we can't tell from here.

However, the Victorian house has cavity walls? That's pretty nifty - lots don't.

(An internal wall can take up to two years to dry out after a possibly damp source is removed? Blimey - that seems a tad long to me...)

Damp meters are not necessarily a 'con', but they can certainly be confused and tricked by any source of surface condition - they might press the probes in to the wall a mm or so, but they are still in contact with the surface of the wall, so if they have any condensation on them (most house will have especially near breakfast/utility rooms) it'll show as a reading.

The 'salts' bit is new to me, but I can see that it too could contribute to false readings.

This doesn't help you, of course, as we still can't tell if the house really has a rising issue.

The survey you had carried out for yourselves will always be 'worst case scenario' as the surveyor's foremost priority will be to protect themselves against any future claim that they missed something.

If the 'specialist' the home owner called out is a properly registered damp specialist who has provided a 'proper' paid-for report (and not a friend of the folks...) then I guess their conclusions are equally as valid as your own guy's.

You can always ask the owner if they've ever seen or been aware of any evidence of damp - mould, peeling paint, stains etc - on the walls in question, and - if they are being truthful - that would be a decent indication. I mean, if the 'damp' doesn't actually cause any symptoms at all, then it chust ain't an issue!

What to do? I dunno. Perhaps ask the home owner to get a further fully-independent specialist in for a survey (if the one she's already used isn't that.)

 

This a outside wall, is the ground below any air vent or damp course, also lack of ventilation can cause problems especially in a ultilty room, if it has a tumble drye which isn't vented to there outside.

If it is damp, there are 'Dryrods' available, which are very good, & easy to install.

http://www.dryrods.com/

 

This look like a product I could use. 12mm seems quite large for a hole, as think the bed joints on my bricks are 10mm.

 

It's a shame that there isn't a slimmer version, say 8mm - 9mm, & you just you a few extra one in a run, because of a smaller diameter.

 

A local guy who has done lots of work on similar houses is exactly the type of guy you want .

Don't forget - when he gives the house the all-clear, slip him a £enner to write a damning report about water pouring out through the plaster and begin you negotiate your discount...


er, only kidding...

 

Someone on a back hander...

 

This guys website makes interesting reading - I have no connection, but am prob going to get involved with a house with some damp probs.......http://www.heritage-consulting.org/damp-advice

 

Just like you shouldn't necessarily accept what a 'pro' has to say, neither should you take in what you see on PooTube.

Both or neither could be right.

Sounds like you are lucky, tho', to have the right sort of person to have a looksee.

On a connected note, Qi reckons there's no such thing as 'rising damp' - it simply doesn't exist.

(Yeah, I don't believe that either...)

 

My younger brother worked for a damp proofing company once. In his own words "They were out and out con artists." Charging customers thousands for unnecessary work, and paying the workers peanuts.

 

Surely the signs will be visible, ie: is the area supposedly damp freshly decorated or is the paint old, if old is it in good order, if so little chance of damp, if fresh, why????

 

A lot of the cause of damp in Victorian houses is down to what has been done to the walls. If the outside has been rendered with Portland cement, that forms a very effective barrier to the naturally water-permeable walls, which were built using lime mortar. If the outside is covered with waterproof paint, it will do the same thing, and to a lesser extent, so will re-pointing with Portland. Rising damp is a myth. I have only seen one case (a burst water pipe) where the water has not originated from higher up the wall (absorbed condensation, leaky guttering, cracks in the coating etc.) has made its way down to either the DPM, or ground level, where it could get no further, and simply 'filled' the brickwork up from the bottom.

If your specialist has been using one of the detectors with metal prongs which are applied to the walls, you should take their advice with a pinch of salt (or possibly salts). These detectors were originally designed to test the moisture content of wood and are unreliable for use on walls. a free-standing humidity gauge will provide a more accurate reading. These can be bought for a few pounds online. The advice to strip off the plaster is sound, but do the same with any external coating too, and hopefully the wall will dry out quite quickly.

Something to be aware of, if you do have cavity walls - very unusual in houses of this age, is that the brick courses are held together with steel ties. These should be inspected to make sure they have not rusted away as this can have serious consequences.

 

The question to ask yourself is do I still want to buy the house if I need to spend £500-2000 on a damp problem?

The house has had problems in the past and will probably in the future. If this doesn't put you off then you can proceed with the purchase and resolve the issue once you've moved in.