It’s a stone cottage built in 1816. One wall of the house is below pavement level, and that’s where dampness is creeping in. We reckon a trench dug between the wall and the pavement would be a lot better and allow the house to deal with dampness as it has done for the last 200 years. Surveyor is sticking to his guns (odd that, seeing as he works for a chemical damp proof treatment company) and his report needs to go to the mortgage company for final agreement.

It’s not a cost-thing, as it’s roughly the same to get a trench & proper drainage dug in. I’ve just seen lots of photos of damage to old buildings where a chemical damp proof treatment has locked the water in to a wall it would otherwise have evaporated from, and I don’t want that happening to my house.

What options do we have?

Find another surveyor?

Would you ‘own’ the pavement? Not sure the LA would like a trench to be placed right next to a pedestrian route?

I have no experience but I’d tend to agree that anything that stops old houses ‘breathing’ is not a good thing.

Get a surveyor who doesn’t work for a damp proofing company to have a look would be my advice.

his report needs to go to the mortgage company for final agreement

I doubt they’ll care.

Our report was about an inch thick and we’re still to see any evidence of half the things that were mentioned in it, including Japanese knot weed, damp, and all sorts.

Is he your surveyor or the lenders? If it’s the lenders there’s probably not much you can do. We had a lender’s surveyor ask for a structural engineer’s report on a property for a remortgage. We complained, the surveyor stood his ground. We paid for a structural engineer who said there nothing to worry about and that the surveyor was obviously not familiar with properties in our area as this was a very common thing to happen where we live and not a threat to the building. And it cost us £250 for the privilege.

Yeah, we’re already in the process of contacting another surveyor.

How does it affect mortgage stuff?

If it means we have to fork out another £6k, then house sale doesn’t happen.
If it means sellers have to take a £6k reduction in agreed price, resulting in a £6k less mortgage but we still have to fork out that £6k, then house sale doesn’t happen.
If sellers take a £6k reduction in agreed price, but mortgage company lend us original amount based on the difference going on damp treatment, we’re OK.

Which is most likely? I’ve only ever bought one other property, and that went smoothly, so no real experience of the whole process.

There’s useful info in here…

http://www.amazon.co.uk/Old-House-Handbook-Practical-Repair/dp/0711227721/ref=sr_1_1?s=books&ie=UTF8&qid=1376996355&sr=1-1&keywords=old+house+handbook+a+practical+guide+to+care+and+repair

… old houses lack DPCs but can get on fine without them. Remember to take out the trench in stages, not all at once.

Dont get the damp proof!! There are lots of examples of the damage these do to old buildings.

I live in an old solid walled cottage, when purchasing I used Pete from Heritage house to do the survey. Pete has lots of experience of old buildings and fighting surveyors who recommend inappropriate treatments.

I would get in touch and see if he can help, start at heritage-house.org, lots of info here about bad use of damp proofing.

ask him how he plans to remove the injected chemicals if they dont work.

im a stone mason and work mainly with restoration of solid wall buildings, mainly reversing the damage done by adding new materials. i would suggest a ‘french drain’ ie a trench with a porous pipe at the bottom filled with gravel, and capped off with slabs etc.

while i dont have experience of the probs you have in terms of lender/buyers etc i do have experience of the hopelessness of dealing with a lime mortar wall pumped full of silicone based sealant.

Just spoken to Pete and he’s putting someone in Scotland onto me. Ta muchly, clivecoolhead.

can you let us know what sort of price they come in at for a survey.

I’ve got an old 1850’s canal cottage that has been ‘refurbished’ would like to know whether the work done is problematic or not, before it becomes a problem and from a non based source.

Been reluctant to have a damp survey, mainly because the answer will be inevitably, ‘yes, and here’s the cost of our damp proofing..’

Ox – contact Historic Scotland and get a hold of a surveyor they reccommed/endorse they will be more keen to avoid the Chemical
nonsense.

downloads here:
http://conservation.historic-scotland.gov.uk/publication-detail.htm?pubid=6976&searchterm=damp&category=&date=&page=1

http://www.spab.org.uk/

http://www.heritage-house.org/pages/managing-damp-in-old-buildings.html

can you let us know what sort of price they come in at for a survey.

Initial cost of survey is £120.
Cost of work they reckon doing: £4993 + VAT
It’s basically remove plaster up to 1m for the entire north side of the house, delta plaster membrane, chemical damp proof course then replaster.

Have a look into what the RICS advertise about damp proofing. It’s quite interesting…

Linky

It’s such an obvious conflict of interest that you start to wonder whether the mortgage company is aware of it. Chances are they won’t care that their surveyor may be abusing his position.

And have a read of all the ‘chemical damp-proofing is a con’ materials online.

nitial cost of survey is £120.
Cost of work they reckon doing: £4993 + VAT
It’s basically remove plaster up to 1m for the entire north side of the house, delta plaster membrane, chemical damp proof course then replaster.

ta,

was more about what heritage house quote, just a ballpark 🙂

Ah, still waiting for him to get back to me. I’ll update when I know.

For the last house we bought, two damp companies told us we needed a chemical DPC in a victorian semi.

It, blatantly obviously, already has one of the stupid things. The injection holes are clearly visible!

Independent damp surveyor came round and made a few suggestions (live in it, turn heating on (house had been unoccupied for 6 months over a winter) open windows, re-render wall, dig French drain trench thing as described above. well worth the £150 he charged.

Damp people seem bigger con-men than double glazing salesmen to me.

Chartered Building Surveyor here, some decent advice already given. Your idea of the French drain is best OP, chemical dpc’s don’t work in stone buildings generally, they are usually constructed of two leafs of stone with lime mortar and stone infill between. The silicone CANNOT stop moisture rising through the infill material and it stops the stone doing what it should- absorb then evaporate off the moisture later.

In buildings of that age you need to stick with traditional materials and techniques generally, the builders of old built well and built to last. Let the building breath (no cement, ventilate well etc.) And all will be fine, if your mortgage company causes you hassle I’d be surprised.

Why is a damp surveyor involved anyway? I thought you were purchasing when I first read your post. If you have trouble go to the RICS website, http://www.rics.org and look for a chartered building surveyor. They chase the charlatan and give you some help.

Double post…

We are purchasing. The surveyor/valuation guy for our lender stipulated a damp & timber report. The lender confirmed that the mortgage is dependent on the report.

Aye, that’s typical backside covering by a valuation surveyor, unfortunately, which leaves you in the hands of a “specialist”. You need another surveyor.

Speak to your solicitor and lender to see if you can take their report and not implement it or get an alternative conservation surveyor to look? Sounds like a discussion with your lender would be most help I’d say. How it goes ok.

something is wrong with that spec you dont inject when useing delta membrain. the membrain is basicaly a plastic sheet fixed to the wall and plasterd on but it needs a channel in the floor to drain any water away. take a look on sovereign chemicals web site

….which is solving what exactly Robido? My point is that you are masking a problem with a tanking system, tanking should be a last resort and not a go to solution. In a city centre basement you have limited options perhaps and this may be suitable. In any case, you need to drain the water from behind the tanking, which can be difficult in a basement.

Removing the source of ingress with French drain or reducing ground levels, or both!, is always best. Always.

As a side note, it’s hilarious that these “specialists” get to diagnose and remedy something that they often have little formal training in other than that provided by their parent company, who are often chemical suppliers…

It does seem to be a case with damp specialists of them turning up and saying “Right, I’ve got the perfect solution in the back of the van. Now, what’s the problem?”

I do hope the mortgage lender and their surveyor are willing to accept alternative viewpoints.

A chemically injected DPC won’t work very well at all in stone, there are just too many voids & irregularities for it to go to form a continuous layer at any level. Besides which, the problem is more likely damp coming in horizontally than up from below, so a DPC is unlikely to do much good, even if it did work.

A french drain type arrangement would be your best bet in my opinion, providing you have somewhere to discharge the collected water & access/permission to the front to carry out the work.

You could also include a polythene damp proof membrane against the outer wall (not bonded or glued) before you lay the pipe and backfill, as this should help stop any moisture getting against the wall, and not reduce the ability of the wall to breathe as much as a paint on/fully sealed tanking system or bituminous coating.

I’m a building inspector by the way……….

Thanks for all the info so far. It all rather confirms our ideas about what should and shouldn’t be done to the house.

It’s just convincing the people who need to be convinced that we’re not clueless chancers now…

As core says. Damp proofing in random stone is pointless! A fixed course of bricks is acceptable because a level can be decided upon, however that usually works for rising damp. By the sounds of this situation the only thing that would work is a tanking scenario.

As wrightyson. Sound likes the issue is relating to tanking not rising damp.

One wall below pavement is… so the remaining walls don’t have this problem. Plenty of solutions on the market it depends on whats right for the application and problem.

Independent damp surveyor came round and made a few suggestions (live in it, turn heating on (house had been unoccupied for 6 months over a winter) open windows, re-render wall, dig French drain trench thing as described above

Pragmatic… be careful with French drains. Mate did this and basically provided a waterway into his lounge subfloor. As the ground at the bottom of the trench had poor permeability the water, now concealed sat in the bottom of the trench and percolated back through the substructure brickwork into the void under the timber floor.

I’ve had a decent conversation with someone from Historic Scotland today. He reckons French Drain with bentonite waterproofing along the bottom to prevent the above.

I’ve also had another look at the initial survey. Vertical damp proof course and “special plaster system” required on most internal walls of the house. You know, the ones that divide one room from another, and have no contact with the outside at all. How on earth does that work?

Is the pavement actually casting water on to the wall, as in a fall towards the house? If this is the case id avoid opening any permanent trench up along side the house. I’d open up, tank and reinstate the footpath as it was because its acting as a cover within its self to the ground below.

As for the internal walls that can only be rising damp.

The pavement is pretty much level, it’s more a case of damp earth under the pavement being in direct contact with the house wall.

And as for rising damp, that may well be the case, but how would a vertical DPC counteract that?

We, and those we’ve spoken to, prefer aeration and ventilation to snake oil and incompetence when it comes to interior walls.

Its 200 years old! FFS

aeration and ventilation

Plus 100000000000

As for the internal walls that can only be rising damp.

No such thing some would say – http://www.askjeff.co.uk/rising_damp.html

I bought a Victorian terrace house years ago, damp came up on the survey and lender held back £1k until I had damp proofing sorted out. I never did and a few years later remortgage, no damp came up on the survey for that.

hsbc mortgage by any chance ?

NatWest actually. HSBC wouldn’t accommodate due to a long, boring and ongoing situation regarding the feckless oafs at the now-defunct Edinburgh Council Property Conservation department.

NatWest have been more than helpful the throughout the entire process. Up until this point, that is.