How much to reinstate a suspended floor

myhooose

I'm currently in the process of buying an average sized 1910 (ish) semi. The survey has and a dpc company have stated the property has rising damp in all the rooms.

having read this article -http://www.buildingconservation.com/articles/risingdamp/risingdamp.htm
I have come to the conclusion the damp problem is caused by the replacement of the suspended floor downstairs with a concrete one as the moisture that would normally evaporate through the floor has nowhere to go.

Can anyone give me a vague idea of the cost to remove the concrete floor and reinstate a suspended floor? I'm guessing it's quite a lot.

macman

The first thing you'd need to advice is the area to be replaced.
If the concrete has been laid on a proper DPC there should be no problem at all.
Rising damp is what comes up from the ground below, not the same as internal moisture which would evaporate in an upwards direction through normal air circulation.

wallbash

I think you need some truly independent advice .

i.e not from a quote ...dpc company

Ripping up a concrete slab !! which is ( with a dpm ) more than adequate and replacing it with a suspended floor seems a retrograde step .

dougk_2

First of all "rising damp" is a bit of a myth and a con used by those who wish to sell you various treatments. Although it does exist, its quite rare to find a genuine case.

Read these articles.
http://www.konrad-fischer-info.de/2auffen.htm
http://www.whatprice.co.uk/household/rising-damp.html
http://www.askjeff.co.uk/rising_damp.html

What has possibly happened in your case is that the concrete floor has bridged the damp proof course, and the underfloor air circulation has gone.

Its more likely the damp inside the house is caused by poor ventialtion (as the air cannot circulate after the suspended floor was replaced). Installing airbricks may well provide a solution. Whatever you are told the "rising damp" could not have travelled up to the first floor, so if thats showing as damp then the dpc are just trying get some money for nothing.

rustybucket

When we bought our old house, the survey said we had rising damp. Ended up with 5 different free quotes from dpc companies and they all gave different readings as to where the problems were......Hmmmmm. So I paid for a survey.

We had to replace our concrete floor which had no damp proof lining and was in awful condition. Also had to replace out concrete drive. If I hadn't paid out £500 for an independent survey I would have just spent money on a chemical damp course for the walls. I wouldn't have solved the issue which was the floor just would have put off the inevitable.

You tend to find most surveys state an old house has damp issues. Read those articles, especially the askjeff one.

dougk_2

Old houses may well be "damp" to some degree as thats how they were designed to be. Its our lifestyles that lead to the problems or excessive dampness with central heating, double glazing and basically sealing our houses so they are airtight. Modern plasters and paints don't allow the walls to breathe as they would of done with traditional materials.

myhooose

Thanks for the replys and links.

I've had a chat with the surveyor who has recommended I try a different company to do the survey, This comany is a national chain who inject the dpc in to the motar and not the bricks.

The house already has a slate dpc and a chemical DPC injected into the bricks.

macman

myhooose wrote: »

Thanks for the replys and links.

I've had a chat with the surveyor who has recommended I try a different company to do the survey, This comany is a national chain who inject the dpc in to the motar and not the bricks.

The house already has a slate dpc and a chemical DPC injected into the bricks.

I used the phrase 'DPC' in my earlier post and should of course have said DPM (damp proof membrane), as pointed out by wallbash. If there is a fault in the DPM (which runs under the concrete, not under the walls), then reinjecting the DPC is not going to cure it.