Comrades:

My house is a bit damp. It’s damp because it’s located in a damp valley, not because there is any water ingress.

My house has a small room off a bedroom which is used as a linen/files closet. It’s finished, about 1.5m x 2.5m and has no windows. If I leave the door open to the well-ventilated, bright, dry bedroom and put an electric fan on a timer to keep the air moving for a couple of hours a day, do you think that will be enough to keep the linen and paper getting manky/mouldy? Or should I shut the door and whack one of those blue bucket things in?

Blue buckets?? Just add A few full spectrum lamps and grow some Geraniums or something.

I’d leave the door open and see what was happening above / below the cupboard ( outside walls, guttering etc but especially above ). Water doesn’t just creep out of the ground more than a few inches. I live in a damp valley and we had the back windows properly sealed, ran the down pipe 10 feet into the garden and dug a large French ditch with underground run-offs into the garden.

A house won’t be damp without water ingress. Check your gutters, run an eye over your pointing, borrow a ladder and inspect your roof tiles. If your house is damp it’s getting in somewhere from above, I promise.

It’s not damp because of water ingress. It’s just a damp climate. It’s a big house and nothing’s ever totally crisp dry: paper, linen, plasterboard.

Blue buckets: big tubs of calcium chloride that soak up moisture in the air.

Dude, my folks live on Skye and their house isn’t damp. That’ll be the wettest place in the UK. Look up – that’s where your problems lie. Buckets of chemicals are unlikely to be the answer.

What they said. It isn’t ‘the valley’. People live in Seathwaite and don’t have damp problems. It is not a damp climate. It is the house and either it’s construction, a fault, or how it is being used.

Get a dehumidifier

^^^^^^^. +1

Dehumidifier.

The OP will be right; I’ve noticed that when you walk or ride into shady leafy valleys and woods you can feel an increase in the humidity. It’s more noticeable when you emerge into the open air and feel the dryness. A cottage on Skye may be in the wettest place but it’s also very windy and not surrounded by green trees that trap humid air.

Ventilation will reduce dampness in the house and a multifuel stove somewhere in the middle of the house will warm the entire building and suck massive volumes of damp air up the flue. That’s no good in summer though so the only answer is something cold that condenses the moisture in the air and encourages it to form droplets and run into a container – either a dehumidifier or air conditioning. The only difference is that AC exhausts the waste heat outside the building and a dehumidifier just recirculates it inside.

A dehumidifier may help if it is really bad

If the entire valley is damp then you’re going to need a big fan.

While the room may be damp, it won’t be caused by just you living in a valley – there will be a fault, somewhere. And it may be in the actually construction of your house, if it’s not a leak.

A humidifier will sort it.

Alternatively, can you get a window or a vent fitted or does it adjoin another property?

Install Positive input ventilation unit, problem solved.

This is singletrack so some will disagree!!

As I wrote, a stove is as good as positive input ventilation; it sucks massive volumes of air up the flue.

So is it really a condensation issue, rather than damp?

Is the damp causing the condensation or is the condensation causing the damp ?

Only you can determine this, please keep us all posted on your findings and hopefully one day this will be sorted.
Sorry I cannot proffer any practical advice or help however I do wish you all the very best.

Good luck