Mould/damp prevention in a semi converted cellar

[PareyMortas]

I posted earlier in the week for ideas for my new futility room which is going to be in the cellar. Someone suggested an extractor fan which has got me thinking and worrying about preventing mould etc. The cellar was 'converted' by the previous owner, in the buying process we found out that it doesn't conform to building regs and wasn't done with a pump or sump. The floor has a waterproof membrane as do the walls which were then boarded onto a metal frame with waterproof boards.

My intention is to dry clothes in the tumble dryer and also to hang clothes that can't be tumble dried in the winter, so there could be a lot of moisture in the air. There are two rooms, one has a radiator but the one earmarked for utility (darker, small window) doesn't have any heating but neither room has a door and they're next to each other.

Would I be mad using the room in this way? If I DH install an extractor fan would that be enough? I don't want to create any long term problems, but I have been looking forward to not having washing etc on the kitchen.

As well as an extractor, you need a fresh air inlet. Preferably multiple air bricks at both ends of the cellar so there is a constant airflow even when the fan is not running. Use a vented drier not a condenser so that it sucks air out of the room and blows it outside. Even good condensers create some humidity in the room.

The method of construction you describe means that water will run down the walls behind the cladding and collect under the floor, so that space should be separately ventilated to the outside with a lot of airflow, and may also need a sump and pump, depending on how wet it is. If there is any wood behind or under the membrane it will rot.

If you are hoping to hang wet clothes up to air you will need a strong and constant airflow. It will be fairly cold.

Thanks PigletJohn. Can a sump and pump be retro fitted or am I stuck with it as it stands?

it can.

Probably a trap-door in the lowest part would enable you to have a look and see what's going on.

the sump needs to be lined with no-fines concrete, which is porous, otherwise the pump will suck out water and mud, and the mud will b the earth being sucked away and leaving an ever increasing cavity.

You might decide to have the floor dug out and a new one laid. You can get special tiles for cellar floors which have a drainage gap underneath. Modern cellar thinking is that you will never keep all the water out so you have to capture and remove it.