What are the main signs of damp in a house that is up on the market apart from the smell?

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A question by smudge :  Me and partner have seen a house that we really like. The vendors accepted an offer but the sale collapsed because the new buyers thought the house was full of damp. What are the main signs, and how much would it roughly cost to get the house damp proof course done?


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not all sources of damp are from the DPC it could be damp entering through the walls if the cavity has been breached, or through roof problems.

Main signs.

  • discoloration, discontinuities of color
  • a chilly damp feeling (although quite often that is nothing more than the house hasn’t been heated or ventilated)
  • wallpaper lifting or cracking …. although this can be a sign of (dodgy DIY). ifd the cracked paper is solid/firm then its NOT damp)
  • damp patches on external walls, at or near floor level on walls, at or near joints int he upstairs ceilings
  • Moulds & other fungal growths
  • Excessive condensation
  • pooling of water on ground floor tiles, or a feeling of dampness on those tiles.

also look for changes in the plaster up to 1 metre above floor height there is no way to know what it would cost to do a damp proof course… it depends entirely on the size of house. The one thing you can guarantee is that if you call a damp proofing company to look at it, they will recommend / find damp. Quite often the DPC may be fine. it’s just the property hasn’t been lived in.

consider getting an engineer to look at it.

one thing you could do is do the DPC yourself. DPC guarantees are just about worth less. most guarantees are for the chemicals (which are very cheap. it’s the labour cost that is the expensive bit. You could quite happily install a new DPC yourself… it would take time but if you are on a tight budget and have the cash available it’s a perfectly good option. It’s not if you expect to resell the property in the near future.


Damp has many causes and often there is more than one cause so it’s good to see you taking a logical approach and eliminating potential problem areas in the first instance. Your gesture regarding the so-called damp proof “specialist” is spot on as, generally speaking, these people are sales based and not interested/capable of actually tracking down the source of excess moisture – which takes knowledge, patience and a systematic approach as you have demonstrated.

“I’ve just discovered damp in the corner of one of my rooms, ground floor flat. The old laminate flooring in that corner feels spongey and has swollen up to open up a crack in the joins, and this has also pushed all the other laminate joins in that room to compress and start sitting proud at their seams. The drywall (dot and dab walls) is damp at least up to the bottom of the radiator, bottom 6-8inches or so. Radiator on that wall. My guess is it’s either an issue with the DPC in that corner of the property, or a leaky pipe on that radiator. Is my best course of action to just get busy cutting out the sodden drywall so I can get a good look at what might be the problem? Management company deal with buildings insurance and I’m expecting them to be completely unhelpful in getting any of this investigated.”


“A big sign is the black or green Mould growth around windows and skirting downstairs and in ceiling corners near an outside wall and windows upstairs. Obvious damp patches on the ceilings will be an indicator that water is coming through the roof. If you can borrow or buy a Protimeter this can detect damp in walls. If there is a history of damp and perhaps a previous survey has highlighted the fact, then the vendors are duty bound and MUST tell you about it. They cannot hide known problems. So, you need to ask them outright. If they say that there are no problems and your survey uncovers the damp then they could be liable for correction.

Be careful and listen to others as a survey could cost a great deal and then you may not want to buy. To redo or even add a damp course could cost as little as £500 to £3000. Depends on the scope of the work and the size of the house. Good luck.”


“I believe there are a few good ways to check for dampness in a house:

1. Look at the baseboards and/or crown moulding. Did the sellers replace it? Find out why. Was it only replaced in certain rooms? Find out why. Sometimes replacing the moulding is an easy coverup for areas where seepage was occurring.

2. What rooms have been repainted & why? Were certain walls repainted and others not? These can be signs of cover-up of stained walls from water damage.

3. Check the room/closet with the water heater. Sure, there’s going to be some damage from moisture, but is it just limited to the immediate surrounding area? If the drywall is soft in that room, it could go to a larger moisture/water problem elsewhere in the house (or an insufficiently insulated water heater).

GE Protimeter BLD2001 

Good luck!”


“Musty smell, discoloration on walls, possible mould on walls/ceilings.

Not sure how much it would cost to get it damp proofed, but if the damp is already there, you’re looking at lots more money that if it was for a purely preventative measure. Like as in, having to replaster and rebuild bits.

Best thing to do is get a survey done on the house, and if damp is found (and you and your partner want to fix it up yourselves), speak to the vendor about knocking money off the asking price to cover the costs (else the vendors won’t be able to get a buyer!).”

Source(s): My student house was full of damp, and my landlord had to get people in to pull off all the plaster in the living room. Also, one ceiling collapsed!

“Was looking at some “damp” in a friend’s house at the wall/ceiling junction that has cause wall paper to peel down about 6 inches, few black mould spots on plaster and discoloring on ceiling. The wall backs onto a chimney flue in the adjacent room which has an open gas “coals” fire vented up the old brick flue. she paid for 2 new gas cowls but that hasn’t sorted it. Chimney breast only seems to be in one room and a bedroom above. wondering if breast has been removed from back room and back bedroom above. Next step is a look in loft, they are internal walls.”


“You could hire a de-humidifier for a few days. It sounds like you’ve got a chip board floor under the laminate. Chip board really stinks while it’s wet. The smell should stop once the floor has dried thoroughly. Really, the best way to sort the problem is to lift the laminate let the floor dry and fit new laminate. Good luck.”


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