Soggy floor boards in top floor flat?

[DIYdamsel999]

Afternoon!

I’m looking for some advice with my penetrating damp issue. Mainly because I don’t really want a damp specialist in during lockdown, so if possible would like to find a remedy to help the situation in the meantime.

I’ve lived in my flat for two years, it’s on the top floor of a large converted 1903 build.
The outside got re decorated 5 years ago.

My first winter in the flat, my internal paint started to bubble and form salts under it- I read that it’s because old houses like this need ‘breathable clay paints’

Anyway it has since got worse and now my floorboards (original pine boards), are sadly rotting away.
I don’t think it helps matters that the window sills have paint flaking off left right and centre. I’ve found a silicate paint designed for old buildings, but have read you can’t paint windowsills when the temperature is below 10 degrees.

What can I do to help prevent further deterioration to my floor before I get someone in the help cure the damp issue? Any suggestions please?

The flat is along the coast so gets an absolute battering from the elements!

I attach photos of the wall and the poor condition of the outside. I believe the walls are solid stone walls

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[Ken010]

What at times can occur is that the floor board itself, can touch the inside face of the external wall.

If the walls surface is damp / wet the floorboard can / may rot?

Other scenario, The floor joist that is embedded in the external wall may ??? have been affected by wood rot, this rot can be transferred to the flooring??

Ken.

[wes56]

Maybe the OP is still with us but for information about what his pics show i'll try and explain.
There's obviously penetrating damp, the blistering and blown wall paint, and the rot damaged floor boards plus the nail heads that can be seen to be rusting.

The rot is serious because its dry rot, notice the white stuff and the tiny decay squares. Dry rot means the problem has been going on for some time, and the damage and a mushroom smell should have been noticed two years ago when the OP moved in.
By now the joists will have been infected and the dry rot will have spread up the walls behind the plaster.
The newish looking skirting boards could have been to replace rotted out, pre-sale skirting boards?

The outside render has been patched painted to blend in. Moisture is probably entering through the render and the stonework.
The stone sill should slope away from the bay and be silicone sealed at the places it touches the window frame and wall reveals, it should have a throating.

Interesting there's no mention of the neighbour's below complaining about damp or rot from above?

[fin]

to be fair that doesnt look exactly disastrous to me anyway. ya often find timber flooring in old houses with rusted nails and perfectly sound joists.

it would probably be worth maybe popping off a skirting board to check behind it and also cutting that damaged piece of flooring out and replacing it with either an old piece of damage free flooring of the same size or getting a new piece and addapting it to suit as newer stuff will possible be smaller and maybe slightly thinner.

chances are the floor joists below will be sound.

it maybe worth while asking a rendering company their thoughts on what is going on outside. it may also be worth speaking to a building chemicals type rep to see what products may be available to coutner the damp on the walls... also maybe worth buying a cheap damp meter to see if the walls are indeed damp.
https://www.amazon.co.uk/Brennenstuhl-1 ... %3D&sr=1-3

it could even be sold on again afterwards if it was just going to forever sit in a drawer or whatever.

[wes56]

You dont know what you are talking about.If you know nowt then say nowt. And who said disastrous?
You can see very obvious dry rot and penetrating damp in the walls and all you can say is to be fair? Why not be fair to the woman poster instead of talking b..ks and possibly costing her a lot of money?
Are you daft? Go and buy a damp meter and bring in a damp company salesman you advise. Then bring in a render guy. Do you imagine any of these salesmen will come and go for free? Like damp companies are well known for free jobs. Do you live in this world?

Chances are the floor joists below the rusty nail heads and rotting floor boards will be sound you write. No they wont, rusty nail heads are always signs of excess moisture.
The skirting needs removing, all the damaged boards lifting and all plaster in the bay knocked off to window ledge high. Then the poster will have a chance to see things properly and post photos on here.

if you know nowt say nowt