Damp found in Level 3 survey but not by the DPC specialist survey

kaboo

Hi everyone,

A bit of conundrum here. A house we are interested in buying and are quite into the process by now (mortgage and searches done). This was built in 1930s. Our level 3 survey found low level damp in several walls, 20% in a couple of walls and skirting board, and saturated readings in 2 spots. Surveyor's opinion is that the property had an unusual damp proofing course (DPC) when it was built. The two layers of blue engineered bricks that are supposed to be much more impervious to moisture than the red bricks. However, in his opinion they are not as effective as a slate DPC because these impervious bricks are still set in normal lime based mortar through which moisture can rise. So, most likely the DPC has failed or is ineffective and is causing rising damp and giving high readings in the walls and skirting. 20% and above moisture for prolonged period is likely to cause timber rot. However, neither us during our visits to the property nor the surveyor saw any signs of dampness damage externally on the inside or outside walls. The surveyor has recommended chemical DPC in the outside walls, and lime based plaster and breathable paint on the inside.

When we discussed this with the EA, they told us that owners had recently got a damp survey done by a damp specialist (quick Google says that their company is a popular DPC treatment specialist). They shared the report with us. DPC specialist did not find any damp. In a couple of places it was below 20% level, hence no action was recommended. We were curious for the reason behind the seller's doing there own damp survey. When we asked we were told that a buyer previously interested in the property had also found damp in their homebuyer's survey - we cannot see this report to verify. 

So, 2 home surveys found damp, and DPC specialist did not. All three surveyors used electronic meters.  All three surveys were done within weeks of each other - like a gap of 4-5 weeks. We are not sure what to do now and trying to read and understand as much as possible! So please share your opinions. 

Cheers

stuart45

If a company that sells the treatment finds no damp in the wall then there probably is none.
Slate DPC's were set in lime mortar the same as bricks were and half bonded (2 courses), so there is no real difference there.
Are the walls solid or cavity?

AdrianC

Surveyors use a buzzy box and a healthy dose of paranoia. The damp specialist is... well, specialist.

If they're not finding anything, there probably isn't anything to be found.

BUT... If you didn't pay for the damp specialist yourself, you have no comeback if they are wrong. You would against a surveyor you'd hired.

FreeBear

kaboo said: The surveyor has recommended chemical DPC in the outside walls, and lime based plaster and breathable paint on the inside.

Whilst the surveyor may have detected something on his little meter, there are plenty of things that will throw the readings out. They can not be relied upon to give any worthwhile reading except on untreated wood. That said, he is partially correct in so much as recommending lime plasters & breathable paints - These will complement the materials originally used to construct the property.

As for chemicals slapped on the outside wall - Save your money. They are a waste of time and leave you with a row of holes in the brickwork that are impossible to hide. Whilst engineering bricks make for an effective DPC, poured bitumastic was also used as a damp proof course. It is often difficult to spot this material, especially if it is hidden behind a cement plinth (which was quite popular on 1930s properties). If the damp specialist (he didn't work for a damp treatment company did he ?) didn't find anything, then I'd be content with his opinion - Even more so if he was in the business of selling "cures".

If there is any damp, I'd be more inclined to suspect condensation - It has been a cold winter, and with everyone confined to the home, it isn't much of a surprise that condensation levels are up a little.

kaboo

stuart45 said:

If a company that sells the treatment finds no damp in the wall then there probably is none.
Slate DPC's were set in lime mortar the same as bricks were and half bonded (2 courses), so there is no real difference there.
Are the walls solid or cavity?

Thank you Stuart45. The walls are solid brick, think 9". For just my own understanding, when ever I see pics of blue bricks, as in this property, it looks like they are laid same as red bricks with mortar between them. But slate based DPC looks continuous to my untrained eye. Of course they cannot be continuous like a modern DPC but may be there are fewer joints? 

kaboo

AdrianC said:

Surveyors use a buzzy box and a healthy dose of paranoia. The damp specialist is... well, specialist.

If they're not finding anything, there probably isn't anything to be found.

BUT... If you didn't pay for the damp specialist yourself, you have no comeback if they are wrong. You would against a surveyor you'd hired.

Thank you AdrianC. So, perhaps its better to get our own damp specialist to have a look?

kaboo

FreeBear said:

Whilst the surveyor may have detected something on his little meter, there are plenty of things that will throw the readings out. They can not be relied upon to give any worthwhile reading except on untreated wood. That said, he is partially correct in so much as recommending lime plasters & breathable paints - These will complement the materials originally used to construct the property.

Cheers. All three surveyors (2 from buyers and one from damp specialist hired by sellers) used electronic meters. New plaster and paint would help but they are generally a huge cost aren't they? Another old property that we looked at was in dire need of redecoration, replastering was unexpectedly (to us first time buyers) was one of the biggest expense in the quotes.

lookstraightahead

I have a 'damp' house that I've just bought. You need to do hours and hours of research on your home and really get to know it. It's a
minefield. And rarely as bad as you think.

kaboo

lookstraightahead said:

I have a 'damp' house that I've just bought. You need to do hours and hours of research on your home and really get to know it. It's a
minefield. And rarely as bad as you think.

COuld you please share what all did you research in?

kaboo

Damp could cause 3 main issues for us - one is of course potential damage to the property, second is future salability - our area is one of the notoriously expensive cities in the South-East. And although we are looking to stay long term, we are in very niche jobs and we could be in a situation where we would want to quickly sell and move. Third, I suffer from mold based allergies, so any mention of damp spooks me easily.

AdrianC

kaboo said:

AdrianC said:

Surveyors use a buzzy box and a healthy dose of paranoia. The damp specialist is... well, specialist.

If they're not finding anything, there probably isn't anything to be found.

BUT... If you didn't pay for the damp specialist yourself, you have no comeback if they are wrong. You would against a surveyor you'd hired.

Thank you AdrianC. So, perhaps its better to get our own damp specialist to have a look?

If you're worried, yes.

But not just a salesman looking to give you a price.