Rising humid air from under the floorboards????

[actiongirl5]

Hi,

I have just had to throw out our really nice sofa we purchased from Ikea only a few years ago. The reason for this is because I discovered white and yellow mould spores on the bottom edge of the sofa arm rest. Upon further investigation I found the sofa to be riddled with mould spores.....to the point where the time invested to try and get rid of it would not have been worth it. On top the sofa was immaculate and not issues but as soon as you took the cushions off and seat pads the fun and games really started.

We have also checked the second sofa in the room, there was no signs of mould but a very musty smell coming from under the cushions. At floor level even the wool carpet smell very fusty. We solved some damp issues in the bay window area a few years ago and we thought that was the end of it all. We have wooden floor boards in the living room and from what I can tell damp air is coming up through the floor and into the room. We are running a dehumidifier and airing the room but it still persists.

I was thinking of taking up the carpet which I have always hated and putting down some laminate flooring to prevent so much moisture from the soil beneath the house entering the room. Is sealing the floor a good idea and what would you recommend underlay wise for the laminate. I am not sure if anyone else has experienced this or has any thoughts, but we dare not buy another sofa until we getting the rising humid air sorted out.

 

[Diyisfun]

You need to sort out where the damp is coming from, if that means lifting the carpet & floorboards you better get on it before the winter.

 

[SFK]

lifting the carpet & floorboards
:>

Also check your airbricks are clear, especially those that are opposite the prevailing wind (ie the airbricks where the air exits the underfloor area).

 

[foxhole]

Under floorboards should always be dry and drafty. Damp would suggest little or no ventilation which needs addressing pronto .

 

[cdbe]

Correct me if I'm wrong but I always thought that mould was more a result of condensation than damp? We had similar issue but only where we had furniture against the cold outside walls - no problems with anything on the internal walls.

 

[JP_]

Pull up those floorboards. There should be no warm damp air down there, especially after the summer we just had.
I started investigating a musty smell last year - ended up replacing most of the floorboards, a few joists and some wall plate ends. I knew nothing about building beforehand!
Decided to insulate while I was at it. Doing it all over again now in another room. Insulate with kingspan, seal them up with foil tape, this reduces moist air from the house getting below the floor and rotting the wood. But as for moisture in the lounge / sofa, the room must be very humid for much of the year - do you dry clothes nearby, or is there a bathroom, shower, kitchen near sending in steam that then condenses in the colder room?
My story started here: https://www.diynot.com/diy/threads/my-rotten-floor-s.491659/

 

[JohnD]

there's quite a good chance you have a plumbing leak under there. Do you have a water meter?

the sooner you lift those boards, the better.

 

[actiongirl5]

You need to sort out where the damp is coming from, if that means lifting the carpet & floorboards you better get on it before the winter.

We are going to lift the carpet in the living room and check it out and lift a few floorboards to see what is going on, when we bought the house it had carpet down and the floorboards seemed ok 6 years ago.

 

[actiongirl5]

Pull up those floorboards. There should be no warm damp air down there, especially after the summer we just had.
I started investigating a musty smell last year - ended up replacing most of the floorboards, a few joists and some wall plate ends. I knew nothing about building beforehand!
Decided to insulate while I was at it. Doing it all over again now in another room. Insulate with kingspan, seal them up with foil tape, this reduces moist air from the house getting below the floor and rotting the wood. But as for moisture in the lounge / sofa, the room must be very humid for much of the year - do you dry clothes nearby, or is there a bathroom, shower, kitchen near sending in steam that then condenses in the colder room?
My story started here: https://www.diynot.com/diy/threads/my-rotten-floor-s.491659/

Hi,

I have just lifted the carpet and the floorboards are completely bone dry, nothing weird so far. Also the air is naturally more humid in warmer weather than in the winter, usually the dry air that comes from central heating dries out the humid air. A common misconception is because the weather is warmer the air is dryer but that is not correct. We have a dehumidifier and it does also state this information and this is backed up by a humidity test we have done showing the air is far dryer is the winter and lower in humidity.

There is no leak we no of as there has been no loss in pressure in the boiling and it has has always held good pressure. There is a kitchen the backs onto the the living room but we do always keep the doors shut when cooking or have the back door or a window open. No clothes are dried downstairs and oddly enough we have covered many of the bases to minimise the humidity. I have a week off shortly and from what you and others have said I have some major investigatory work to do.

Thank you for your input.

Mandy

 

[JohnD]

There is no leak we no of

it's the one you haven't found yet that's of interest.

Did you say you have a water meter?

 

[actiongirl5]

Correct me if I'm wrong but I always thought that mould was more a result of condensation than damp? We had similar issue but only where we had furniture against the cold outside walls - no problems with anything on the internal walls.

Hi

You are partly correct in saying condensation does cause mould but so does high humidity, in fact humid air can hold more moisture thus leading to mould. This is what is really odd, the sofa was against a supporting internal wall but not directly against due to the radiator being behind it. No mould anywhere in the house apart from some we get on and off under the bay window during the winter....but only the odd fleck.

 

[actiongirl5]

it's the one you haven't found yet that's of interest.

Did you say you have a water meter?

Hi

That is a thought because our main water does run from the front of the house but is made of lead....does lead usually leak so readily???

We do not have a water meter but we have way above average water pressure in our house and I would imagine if there was a leak this would cause low pressure or slow flow.

 

[actiongirl5]

Under floorboards should always be dry and drafty. Damp would suggest little or no ventilation which needs addressing pronto .

We live in a mid terrace and we have 3 air bricks to the front and 2 to the rear, I had thought that was ample for a small 2 bedro

lifting the carpet & floorboards
:>

Also check your airbricks are clear, especially those that are opposite the prevailing wind (ie the airbricks where the air exits the underfloor area).

Just checked the air bricks and when I put a chisel knife through the holes it hits a brick, we have honey comb sleepers below ground level so I am unsure although I hit a brick there could be a gap either side of the brick for ventilation. They are not the original air bricks but cheap Jewson replacements. When I lift the boards which I feel I may have to do in a few places I will know more and hopefully no moron has bricked up the things.

 

[JohnD]

does lead usually leak so readily???

By the time it's a hundred years old, lead pipes often leak.

The amount of water and pressure you lose might be large or small, depending on the size of the hole.

Clay drains and gullies also usually crack and leak before then. Either from subsidence, or from ground movement caused by wartime bombing.

If the pipe comes up through a concrete kitchen floor, it might be leaking, unseen, in there, but the concrete would be damp and you might see damp patches at the bottom of the walls, or under furniture.

In a terraced house, the water can come from a leak next door.

Do you know anybody young, with good hearing?

Have you got an outdoor stopcock in the pavement or front garden?

 

[Nige F]

t They are not the original air bricks but cheap Jewson replacements. .

Plastic ones ? They give probably 10 times more airflow than the old ones