Hoping for a little advice

Been converting a downstairs room into a bed room however we hit a snag

It's been a bedroom for a few months now and recently we moved the bed out to decorate

Under the bed the walls were damp. The floor was wet to the point of puddling.

At first we thought it was condensation due to the bed being boxed in and having no air flow

However after several days of drying the room out the wetness is still appearing

I have checked the pipes and no leaks so far. There's a dehumidifier in there regulary throwing out water so it might be down to the humidity

However it's also the only external wall in the house without some form of heating on and I can't help but wonder if it's partially down to the uninsulated walls and solid concrete floor

Insulating the walls is on my to do list but unfotunatly it comes behind a new car

Has anyone got any ideas I have the shame to say i have no idea how long it's happened for as for the last 10 years it's been a "general" room

i'd guess you've got it right

air hitting cold external walls always condenses

and the fact that the humidifier is collecting water too shows that'll be the answer.

as you say the only real way is to insulate ...

but another trick that can be used is a bar heater lowdown on the wall

that warms the wall and stops the condensation due to temp diff.

they are quite cheap and quite cheap to run.

Once you have dried out the room, you could try a cheap internal insulation method. If you visit your local B&Q, they sell rolls of polystyrene wall insulation. I have known a few people to use this and it can be very effective.

Thanks guys wI'll look at both

I don't know enough about this to know the answer to my own question, but is it also worth keeping the door to the room shut as much as possible?.

How much effect will there be from humidity from the rest of the house getting into the room to then condense on the cold wall?.

if the wall can't be heated nor cavity insulated as one solution, would decreasing the humidity reaching that wall help?. Would there be an advantage from "dehumidfying that room only" rather than "dehumidifying that room, but effectively having to dehumidify the whole house"?

Does the interior insulation help prevent humid air reaching the cold part of the exterior wall as well as helping avoid the cold reach the humid air?.

If not, does the humidity condense, but just behind the interior insulation?.

Has an air brick been covered up or closed over time to prevent drafts? I have an external wall with an air brick vent, the only external wall with one. I keep it clear for air circulation.

concrete floor will be the cause of the damp collecting. Essentially it is an impervious dam, the walls are generally porous enough to cope with some damp but most brick built houses rely on air flow under the floorboards to regulate the water trapped in the room. Concrete floor doesnt allow the moisture to escape or evaporate unless it is poeperly lined and tanked. You will need to get aone of those fancy moisture bricks set in the wall or get some air flow via a vent. Chimney places use to do that job so if there is a bricked up fireplce it will be a good place to put a vent.