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Where does the damp go? any ideas?

Postby gideong » Sun Oct 10, 2010 5:11 pm

My first post. :o

I am just going through the throws of buying a house with an apparent damp problem. Its had an osmo electro device installed which is broken. We have had a damp company to survey the house who have come up with 7k inc VAT to tank out the ground floor, almost every wall in the house downstairs. I think it expensive for the works they quote but thats another story.

If the walls are tanked out with...


Wont that just hide the damp? Admittedly it will give us a decoratable wall. My question is where will the damp go?

I have seen mixed reports on various methods but i kind of feel masking the problem will only create another problem. Can anyone describe a French Drain and its method?

Anyone had Osmo electro Damp thingy work? Should we go for a repair?

I am thinking if the vendor has had it fitted they must have had a problem but since its not been working and they haven't noticed have they just ignored it or can the problem regress. When i go in the house it feels damp in only one little laundry room and downstairs loo but the surveyor said there was damp all round. Do surveyors see that the house sale is hinged on the work and quote like mad because invariabley the vendor will suffer the cost to make the sale happen?

The house is in 3 levels, a 17C terraced cottage (end) with a 18C gable end extension all thick stone. probably 700mm thick or there abouts. Our damp inspector said injection was not an option because of the different levels. The back of the house faces uphill a 2 meter slope.

I need wise (polite) words
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Simply Build It

Postby welsh brickie » Mon Oct 11, 2010 2:04 pm

never go with 1 quote thats too expensive.Get as many quotes as possible, And haggle dont be afraid to knock the price down .I would enquire on a electrician repairing the osmossis wire aswell
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Postby gideong » Mon Oct 11, 2010 8:39 pm


we have had the one quote from a damp company. We gave the vendors our quotation. The vendors then got the company in who installed the osmo thing. They said they would omit this device from future damp proofing and would then installl basically a tanking system to the tune of 4500 + Vat so 1 k cheaper.
this leads me to more questions which are:

why not repair the osmo electrical device when they installed it in the 1st place?

to repair it can it just be jointed out or does it need a whole new titanium cable?

Where will the dampness go from behind the damp proofing?

has anyone ever gone for an indepant surveyor in comparison to a surveyor with a vested interest in selling a product.

My thought is to get an independant guy in for a proper chartered survey then look at fixing the osmo device.

Our problem is that the mortgage lender might not lend if the surveyors works are not carried out but i really dont want the rooms tanking out.

Should i mask the problem or try and deal with it. HOW?
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Postby john1970 » Fri Oct 15, 2010 9:13 pm

Are you sure the elecro osmotic system has broken? Conventional wisdom is that they don't work in the first place - which is why they don't have BBA certificates etc...

To be fair to the contractor, a cavity drainage system is a fairly sensible option where you have split ground levels. If correctly designed, any water ingress should flow to the lowest point where it can be discharged.

Whether or not 7K is an expensive quote depends on the size of the house. Personally I don't think it is that expensive for an average sized house. You could certainly buy the materials a lot more cheaply than that, but it would take quite a few labour hours to install it to the whole ground floor of a building.
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Postby j.orsi » Sat Nov 13, 2010 10:19 pm

HI, don't tank it, or try and seal it up it does not work. To answer your question the damp does not go away with tanking it is sealed up behind the wall and often drives more moisture up the wall. look at SPAB site for damp in historic buildings.
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