Smell of damp

[mimiku]

So we came back from holiday last week and over the last week our living room is increasingly smelling more and more damp. I think the smell is really obvious, no-one else does, but I’ve got a strong sense of smell and could sniff out damp in our upstairs toilet when everyone insisted it didn’t smell of damp. Lo and behold, peeled back the several layers of wallpaper to find the bathroom wall was covered in mould and damp! So I’m confident I’m not just being weird.

i’ve done the obvious things like pulling out the sofa to check the kids haven’t stuffed anything wet behind it, taken the sofa covers off and put them in the wash etc. hasn’t helped. I want to get a survey done, but being honest I’m absolutely useless and don’t want to go to a company that is going to rip us off with “solutions” that don’t solve the problem as we’ve had this happen in the past.

Spell it out to me, I’m an idiot, what exactly am I looking for in a damp surveyor?!

Thanks in advance.

Get a damp meter first and check.
Have a look outside and check guttering. Go out when it’s raining and see if any water is dripping on the walls or pooling somewhere on the ground.

We have got a damp meter, one that makes a horrible noise where it’s damp. It does it in very specific spots, but if I move it a couple of centimetres in any direction around a spot the meter goes completely silent. This is the same in pretty much every single room in the house and there doesn’t appear to be any rhyme or reason for it because it’s on all different walls, including on our internal upstairs hallway wall. I got my step dad round tonight to see if he could find the source of the smell because he’s good with house things like this, but he couldn’t either. Honestly, I need someone who knows what they’re talking about to have a dig around.

The gutters were checked and fixed earlier this year as it was pouring water onto one of the walls and was thought to be the reason the upstairs bathroom wall was damp. It hasn’t helped though, the paint is flaking away still in the bathroom and the damp meter still reacts to a particular part of the wall so it’s probably worth getting someone to look again.

Should have added this into the OP, it’s a Victorian mid terrace.

Bad pointing on external walls? Maybe condensation on those areas (but why there)?

I honestly don’t know, it’s really weird. Even stumped my step dad who usually has a solution to things that come up. It needs really looking into, but I don’t want to be conned because it was “definitely” an expensive roofing issue causing the bathroom damp, then the guttering, neither of which have completely resolved it.

If anyones got any recommendations of people to use (SE, along the South Coast) or tips on how to find a decent surveyor I would be so grateful!

Damp meters are no good for most houses. See 'Heritage House' website.

I'd check-
pointing, any gaps?
gutters, any (new) leaks?
Any old chimney in that room, blocked up or not, which may be having a problem?
if neither, are there any external drains close to the walls of that room, or even running along close to those walls? Old houses like yours and mine are likely to have old salt-glazed ceramic drains, which do eventually crack and leak. When we had all our drains relaid (needed doing anyway for other reasons) they did find cracks in some sections, though mostly small ones. When they dug one drain out and dug a trench up against the wall because it seemed very wet, water leaked out from under the house. We now have new plastic drains and no longer have a small puddle under the house near that wall (which did have a small damp area inside on it before and no longer does).

Seems unlikely to be condensation if it suddenly started and hasn't cleared up- the weather is nothing special. I know what you mean about the smell, though, I can definitely smell damp when DH can't. But I've been right.

If you do get a survey, don't get one from a company that does damp-proofing. Get a specialist old buildings surveyor, a proper chartered surveyor with experience in heritage buildings and dealing with damp in the same.

IME Damp can come from four places :

i) The ground. Through failure of the damp proof course.

ii) Living. From humidity condensing on the walls.

iii) Pipework failure. This can be a number of causes but includes leaks in pipes carrying the hot/cold water, leaks in foul water drain pipes, leaks in the radiator/CH heating circuit, leaks in external pipework like guttering, leaks in wet areas like seals around baths and showers.

iv) Roof failure, the roof isn't sealed, or water makes its way somehow down the chimney or next to it.

You need to find out what is causing it. 1 is unlikely as it is upstairs. 2. seems unlikely too, because you are not seeing the damp on the outside of the internal wall, only after wallpaper is removed. Is that bathroom used heavily ?

Which leaves iii) and iv). remember water can soak along and up walls through capillary action. Try to find out whether the wall is wetter at the base or the top. Top may suggest a problem in the roof (leaking water tank or leaking roof) or guttering failure.

For the CH check the water pressure in the radiator circuit and whether any radiator pipeworks go near that wall. Do you have to top up the pressure on a regular basis - that might be because the circuit is losing water and it is going into the wall ?

Is there a bath/shower in close proximity or on the same wall ? Try removing the bath side panel and/or shower tray side panel to look underneath and see whether it is wet. Make sure you give the roof a thorough inspection.

Oh and finally ... if you had the guttering fixed - it could just be that the wall is taking a long time to dry out. Sometimes it takes forever. If the bathroom is being used at the same time, this won't help as you need a humidity differential to drive the drying. Try putting a dehumidifier in there to draw out the water.

But ... don't be surprised if it takes a long time to dry it out.

it will be the ground under the timber suspended floor , we had this a couple of times when we lived in a Victorian house. It was basically soft dry soil under (3 foot down ) and when the conditions were right lots of rain and not much wind ( no breeze through the air bricks ) you got a musty damp smell , more so if the door was shut. I think the dry ground under the floor just soaked up moisture like a sponge and made the dry non smelling ground smell a bit .

Never lasted long and only happened a handful of times in 20 years .👍

If you’ve got concrete floors then it’s not that .🤣

Firstly it might be condensation so buy yourself a de humidifier. Second you must find the damp and then understand the cause and tjere is always a cause. Is it an old house or newer house? What floor do you have? Concrete or suspended wood floor? Also do you have a cavity and/or air bricks?