Mould Help!

ScottNelson

I wonder if anyone can give me some advice about mould?

I have a holiday hut in Scotland. No power, no water, lots of rain.
The hut is 50 years old but in good nick. We bought it and started doing it up a couple of years back.
I took a couple of skip dived chairs and a door up last year. After a while they all developed some green mould but it seemed to go away.

This summer we had the hut insulated. Joists attached to the original wood walls, plyboard attached to that with insulation in the gap.
After a couple of weeks we've noticed that black mould spores have formed on the plyboard and it follows exactly where the joists are underneath - not where the insulation is underneath.
This leads us to believe that either there is moisture coming through from outside the hut or that the joists themselves had moisture in them and that is what the mould is being activated by.
The mould is forming in all three rooms.
There is a new wood burning stove in the main room which has been on 3 times which may have led to some sort of atmospheric change inside a hut which hasn't been heated for about a decade.

My guess is that there is moisture in the joists that is somehow being sucked out by the change in atmosphere and then mould forms on top of that. Hopefully it'll just go once the joists have dried out and we can get on with painting and cladding.
That wisdom is based on absolutely nothing but wishful thinking.

If anyone else has any proper wisdom/solutions I'd be very grateful to hear them.

cheers,
Scott

bertiewhite

My Welsh cottage was damp when I bought it and was cured by a combination of:-

1. removing trees close to the house which were blocking out light
2. cleaning out the gutters
3. ventilating & heating as much as possible
4. removing cement render / non breathable paint & re-pointing with lime based mortar.

I don't know if any of these factors apply to your dwelling?

spadoosh

I would guess your walls are wet and the joists are acting as a bridge for the moisture. When was the exterior last treated?

Doozergirl

It's not going to help any if there is no heating, especially given the location

Norman_Castle

ScottNelson wrote: »

This summer we had the hut insulated. Joists attached to the original wood walls, plyboard attached to that with insulation in the gap.
After a couple of weeks we've noticed that black mould spores have formed on the plyboard and it follows exactly where the joists are underneath - not where the insulation is underneath.

Wood is a poor insulator. The insulated areas are warmer than the areas directly fixed to joists so thats where condensation will form.

Its likely the hut needs more ventilation when its empty. Your recent improvements have probably reduced the airflow through it.

ScottNelson

This is all excellent advice - thank you so much.

I've currently bleached the mould to wait to see if it returns.
However. we will now put in more ventilation, heat it as regularly as possible and treat the outside (this hasn't been done in a long time). Hopefully this will make the difference.
Thanks again!

Scott