Three conflicting quotes on damp problem

[Joe Malone]

If I was one of those salesman I'd be struggling to make my commission given my views!

 

[JerryM]

just a point of clarification to help ensure sure people get what they pay for in terms of "moisture meters"

They are not calibrated for use in masonry. The readings are qualitative not quantitative. For example a fully saturated engineering brick will only hold around 3-4% moisture but will register 90-100% on a damp meter

my meter is calibrated for masonry so there are clearly imitations out their to be wary of.

what's important is the previous view that it's who's hand the meters in and a step by step diagnosis starting outside the building to establish the route cause (and more likely causes) before going onto the cure.

 

[Joe Malone]

Jerry, what sort of damp meter have you got? I'm guessing it's not a Protimeter?

I didn't say it was impossible to calibrate for masonry but manufacturers generally don't bother because calibrating for one type of masonry is a useless proposition. There are hundreds of different types of masonry out there, each with a different density, porosity and saturation level. Your meter is calibrated for one! I'm not being facetious here but do you know which one?

Jerry, if the manufacturers could have overcome this problem they'd have done it a long time ago. I'd be more concerned that you were operating under this illusion of accuracy than if you were simply using relative readings.

 

[JerryM]

Joe,

It's bought from the company that i am trained by and buy my materials from. I think you will know who it is but the name of course is irrelevant to this forum.

I also agree (as we do on many things but not all) on illusion being a deep pit to fall into.

On the brick range the working calibration is to 8% and 25% on wood. As i think you said patterns are very important not just readings.


Just a general observation on condensation i made yesterday at my kids school that should be of interest to all. as you do i was attracted to a metal tube crossing a cloakroom. the room was warm - i'd taken 2 of my 3 norm layers of insulation off. the pipe was cold and an amazing amount of water was dripping from the pipe. this i put down to all the kids talking. alas no damp though (well i did not have my meter with me - but no discernable damp and certainly not the smell i love). plenty of ventilation then by the cleaners.

 

[jeds]

I think you will know who it is but the name of course is irrelevant to this forum.

Being always willing to learn I'd still be interested to know what damp meter is calibrated to masonry, and how it gives a meaningful reading across varying materials, densities and pore structures?

On the subject of who you can trust in this business, the fact is it is very difficult to know. An experienced chartered surveyor would be a good start but only if they are specifically trained and regularly do building pathology work - which many do not. Unfortunately, the CS lot have been let down badly over the years by valuation surveyors (sometimes CS, sometimes not) who often have no clue whet they are doing with that meter and so end up report dampness just to cover there asses.

Next are the damp proofing company selesmen - usually referred to as surveyors. Unfortunately, very few of them are trustworthy - even the ones that are fellows of the grand order of damp proofers. I don't mean to say they all don't know what they are doing. I'm sure some of them do. It's because they have been proceeded by thousands of fly-by-night merchants over the years who have taken the money (usually lots of it) and run, never to be seen again. They have specified millions of meters of unecessary works and wrecked thousand of period properties. Much of this of course all started by the valuation surveyors mentioned above, covering their asses. So you can't trust them. Any of them.

Beware also of the damp proofing salesman that says he doesn't do free surveys. He implies that only the cowboys do free surveys and he's a proper bloke that has to charge because he's proper, and not a cowboy. What you need to bear in mind is that cowboys are not stupid. They are very adept at working out how to get you to give them money. They know you've been on google and the forums and they know the forums always tell people not to trust anyone who does a free survey. So you can't trust them either. None of them.

So who can you trust? Well, I said it was difficult. The only way to be really sure is to ask all the right questions and get all the right answers. But then, how would you know what's the right answer?

My advice; go to a Chartered surveyor and ask them if they are experienced in dampness and general building pathology? If not go to the next one. Then ask what it would cost for a brief visit to make an initial assessment of your situation and give some guidance on what to do. Very often that visit is all that is needed and the surveyor will be able to see the problem straight off and advise you how to proceed. If a more detailed survey involving destructive testing is required then obviously the surveyor is now in a position to give an accurate quote.

There is one other option and that is to go to to a specialist consultant. These people are not generally involved with damp proofing firms and usually only do consultancy and expert witness work. Unfortunately these firms often avoid direct domestic instructions so it might be difficult to find one. Also if you do find one you will need your gold card.

So, not perfect and rather depressing in a way, but I think it's the best you will get.

 

[JerryM]

jeds,

I'd still be interested to know what damp meter is calibrated to masonry, and how it gives a meaningful reading across varying materials, densities and pore structures?

the reason i used irrelevant is due to the forum rules on advertising. however to get answers to you question you would need to travel to Barrow in Cumbria.

who you can trust in this business

i like and gel well with your thoughts even though you've left us installers off your list. only a thought but i often find where the wheels come off is when "destructive testing is required" ie the initial survey is inconclusive. i believe the installer has the advantage at this point being able to include these costs as risk (through experience) and thereby minimise the overall cost to the customer.

 

[Joe Malone]

only a thought but i often find where the wheels come off is when "destructive testing is required" ie the initial survey is inconclusive.

Jerry, I find this comment unusual to say the least. Unless a destructive survey is carried out then any survey for rising damp is inconclusive! You must establish that moisture is present at depth within the masonry to support a rising damp diagnosis and this can only be done by carrying out invasive tests. This would then need to be supported by by a positive result for Nitrates and Chlorides in the salts analysis test. There is no other way to do it. The wheels are coming off because these tests aren't being done.

 

[JerryM]

Joe, sorry for any confusion.

you are exactly right.

what i say is the installer is well placed to do the invasive test (he does not mind making a mess as he has the means to clear it back up again). a paper report alone is not good enough.

 

[Joe Malone]

It's an interesting point Jerry but if the installer is there hasn't rising damp already been diagnosed?

 

[JerryM]

Not always the case that rising damp has been established when the installer is called in. sometimes a survey has prompted the enquiry but generally the customer requirement is survey and advise. Whether the customer has any prior info or other quotes i for the majority never know and not particularly interested.

 

[totoisacat]

Forget meters adn type of etc.
I would have thought some basic questions could be asked and responses to such may help find the cause easily, though depends on answers to questions!
1. How long has the damp been noticed. If present owner has seen devlopment after they moved in the something has changed to create it. have the added central heating since purchase. They mentioned some cold walls...
2. Are their air bricks? Are they clear?
3. Can they see a damp proff course vsisbly..
4. Was the problem noticed when they moved in?

My 'guess' is relates to heating and lack of air circulation...but hey i am only an amateur, unlike the surveyors who came round...

 

[lucyPower]

We have had three surveyors from various companies (two local members of the Property Care Association, and a national company) looking at the damp problem in our house. Can anyone help with the following as they have all come up with different diagnosis and solutions?

First surveyor:

Rising damp all around the inside of the external and internal walls (but not bay window area) in the living room. Rising damp in internal breeze block walls in dining room, toilet, larder and kitchen. Solution: hack off plaster on all affected walls to 1 ft, install new damp proof course and re-plaster. Replace affected skirting board. Cost £3,000

Second surveyor:

No rising damp in living room - problem caused by condensation. No rising damp in dining room, toilet, larder and kitchen. Wet rot in skirting boards on internal walls in dining room, toilet, larder and kitchen, as plaster goes all the way down to the floor.
Solution: remove skirting boards and chip out plaster to stop the bridging of the damp course, and then replace skirting boards. Cost £650

Third surveyor:

Rising damp in living room, but only in the front bay window and walls along it. This due to the bay window outside wall being rendered over the damp-roof course. No damp in dining room, toilet, larder and kitchen walls. Wet rot in skirting boards most probably due to a leak of some sort in the downstairs toilet.
Solution: hack off 1 metre of plaster in affected dining room area and re-plaster. Replace all affected skirting boards. Cost £1,100

The three surveyors contradict each other on various points:-

Surveyor 1 and 3 agree that there is rising damp in the living room, but disagree on the scale of the problem, and also on the remedy. One says plaster to be removed to 1 ft whereas the other says 1 metre. Surveyor 2 does not agree that there is any rising damp in the living room.

Surveyor 1 says that there is rising damp in the dining room, toilet, larder and kitchen, whereas surveyors 2 and 3 say that there is no rising damp in any of the rooms.

Surveyor 1 says that the wet rot in the skirting boards on the internal walls is due to rising damp, whereas surveyor 2 says it is due to the plaster being all the way down to the floor, and surveyor 3 says that it doesn’t matter about the plaster going all the way to the floor and it is probably due to a leak somewhere in the downstairs toilet.

Do you have any advice on what the surveyors say and what we should do next?
Thanks in advance!

I had exactly the same experience when we were looking to buy our first home. We had three surveyors, two said rising damp and one said condensation. In the end we found it was condensation and realised that damp contractors generally want to rush in and proclaim rising damp at the drop of a hat.