Very damp house

[CrystalSkull]

I've been looking online but can't find any answers to this, so wondered if anyone here could shed some light on it.

My parents are selling the house where I grew up. I have always had problems with asthma and repeated chest infections. Returning to the house now (since I moved out) very quickly makes me wheezy and short of breath.

Family folklore has it that the house has an underground stream running underneath it. The whole house feels cold and clammy to the touch, and we have had black mould on the walls before. We have also returned from holiday etc. to find the ceiling and walls literally dripping with condensation. A large dehumidifier collects about 5 litres of water within hours.

Will this show up in a survey? Has anyone else lived in a house this damp?

Sorry to be so blunt, but are you serious? What do you think Survey's do?
walk in and look at the wallpaper. They will tear this place apart.
I doubt if anyone will get a mortgage on it.
Would you buy it? Your parants have a huge problem.

It would certainly show up on a homebuyer's report (the mid-level survey) I'd imagine - they have a tool that they put against the wall/floor/ceiling and it tells them if there is moisture present and how much. We had a pipe leak in the last few months and the company used that when they were figuring out the extent of the problem, it was pretty darn sensitive. If it was the more basic survey, I don't know if they test for damp or not. Might be worth getting a damp surveying company out pre-preemptively to try and find out what the issue is?

Also, in my experience surveyors cover their backs to a certain extent. For example our survey mentions that there might be issues with two floors - we've had both up and no issues whatsoever. Also, one cupboard was highlighted as having damp. It didn't say the extent - we actually had a damp proofing company go and evaluate it as we were quite concerned after the survey. We decided to see how it went, and eight months later we've had no issues at all in that cupboard (she says, touching every piece of wood in sight!). My point is, on a survey if they think there could potentially even be an issue with damp, it will get flagged up to potential buyers.

The Surveyer won't have to use any device to test for damp. His nose will tell him.

If it's that obvious a buyer will be able to tell, never mind a surveyor

Is it damp, or condensation? Different causes and treatments.

Does it have central heating? Do they dry laundry inside and never open windows? Do they get black mould on external walls? This is easier to deal with than water coming up from the ground (rising damp).

Family folklore has it that the house has an underground stream running underneath it.

My parents house as a natural spring at the bottom of the stairs! It only comes up when there has been a lot of rain, but when it does it bubbles up through the floor! Very, very old house. It has no damp.
The equally old house over the road has an actual stream running through the cellar. It goes through a little tunnel, down a stone gutter and out the other side. I don't recall that house having damp.

I have to say that it does sound like condensation. Had a terrible problem with people who rented a house from us.

I'd its an old house, I would expect some damp. Goes with the territory. Stream under an old house is similarly not that unusual.

Depends on the source of damp or condensation and if this has caused damage. It's all fixable, but some fixes cost more than others.

you say it is damp after a holiday. This suggests not condensation from wet washing, baths and breathing, but possibly a plumbing leak or wet under the floors.

Is there a water meter, and does the bubble ever stop?

Is there a cellar?

I do realise there is a big problem, but I'm not sure my parents do - and that's what concerns me. They have accepted an offer from a cash buyer so the survey will come next... I know though that surveyors tend to be conservative, and damp 'experts' want to sell their services - so I was wondering how you can tell if it's a 'normal' amount of damp or an unusually high one.

The house was built in the 1920s and has no cellar. If you dig a hole in the garden, though, the water comes up immediately - it's like the water table is right at the surface. We never dried washing inside the house and always kept it well-ventilated, so I don't think it's that. Perhaps the damp problem got worse after a holiday because the central heating was off during that period. There isn't much sign of damage inside but when we lifted the floorboards a few years ago, they were rotten and soaking, apparently.

I guess you have 2 options. Wait to see what the buyers say and do. Or start investigations yourself.

Am not sure how investigations will help at this stage. But if I wanted to understand the cause, I would want to find the source of the damp. As pigletjohn sais, if there is a meter then with all taps off check for any change in the meter. The longer the taps etc are off, the easier this is to do.

Is the whole house damp, or are some areas damper than others? Eg is upstairs damper than down? Is there any sign of rotting wood? Any bubbling or deposits on the plaster?

If you are worried about a high water table or stream, am not sure how to deal with it but understanding the geology might help. Plus if things change after prolonged heavy rain.

Cash buyers don't need a survey, so they might be incredibly lucky. Although if the buyer has any sense, s/he will get one done anyway.

So you have wet under the floors. I would start by increasing the subfloor ventilation enormously, clearing out all the blocked airbricks and cutting new ones. Also put a French Drain round the house or uphill of it, either leading downhill to a soakaway, or pumped out.

It's possible to put as sump and pump under the floor, but care has to be taken not to suck away the mud that the house is standing on.

If the house is already under offer, it's too late to do anything except clean out the airbricks, so please do that.

If the buyer goes ahead they will knock off a substantial amount for corrective work.

Damp treatment such as tanking or injection will be totally useless.

Have they got a damp proof course? Are the walls just sucking up moisture from the ground?