How can I prevent damp in unused rooms if I close them off during winter?

lindatoo

I live alone in a 60's built brick 3 bed semi. I had a new Worcester combi boiler installed in 2016 along with some new radiators and had trv's fitted to the radiators that weren't replaced. In previous years I have heated all rooms in my home as I worry about damp (Not that I have ever had any)  but last year to save energy, I turned off the radiators in the unused bedrooms but I kept the doors open to allow warm air to circulate from the rest of the house.

This year I won't be heating the rooms but I am also considering closing the doors to try to only use heat where I need it. but again I am worried about damp. Is this a bad idea and if not is there anything I should be doing to ensure the closed off rooms remain damp free. 

Aylesbury_Duck

Ventilation.  Close the doors but keep window trickle vents open, or lock the windows ajar if you can.

adindas

lindatoo said:

I live alone in a 60's built brick 3 bed semi. I had a new Worcester combi boiler installed in 2016 along with some new radiators and had trv's fitted to the radiators that weren't replaced. In previous years I have heated all rooms in my home as I worry about damp (Not that I have ever had any)  but last year to save energy, I turned off the radiators in the unused bedrooms but I kept the doors open to allow warm air to circulate from the rest of the house.

This year I won't be heating the rooms but I am also considering closing the doors to try to only use heat where I need it. but again I am worried about damp. Is this a bad idea and if not is there anything I should be doing to ensure the closed off rooms remain damp free. 

Nothing could ensure you as it will all be different from one house to another, glazings, building envelopes, the temperature different between external and internal, etc

What you could do is to try and see what may come. Also do not forget to open your windows / doors for a while during winter if there is a sun and the temperature is quite warm to get the fresh air.

fryedslyce

On sunny & dry Winter days, open the windows right up to get a good airflow.

MattMattMattUK

Buy some of the cheap single use dehumidifiers (Something like the below), if no one is going into the room generating moisture then there should be very little, when they are used up then replace them.

https://www.amazon.co.uk/ANSIO-Dehumidifier-Condensation-Moisture-Dehumidifiers/dp/B015AOGP1S/ref=sr_1_3?keywords=dehumidifiers+disposable&qid=1661518580&sprefix=dehumi,aps,127&sr=8-3

gj373

Bowls of rock salt in the rooms

doesntnotcompute

£3.50 Wilko Silica Cat Litter Crystals 3.8L

https://www.wilko.com/en-uk/wilko-silica-cat-litter-crystals-38l/p/0433627

elsien

Aylesbury_Duck said:

Ventilation.  Close the doors but keep window trickle vents open, or lock the windows ajar if you can.

That's no good if it's damp outside, surely?  

BUFF

I would set your TRVs to 1 or 1.5 rather than off entirely, it varies by manufacturer but that will be ~10C-~12.5C.
At worst, set them to * (frost) - that is usually 7 or 8C.

born_again

elsien said:

Aylesbury_Duck said:

Ventilation.  Close the doors but keep window trickle vents open, or lock the windows ajar if you can.

That's no good if it's damp outside, surely?  

Mould grows in warm moist conditions. So ventilation is one of the best cures. You will not get much moisture in on damp days, compared to the amount the room will generate itself. From the likes of condensation on the windows. So go round and dry windows when condensation in there.

GaleSF63

Try it. You can always go back to leaving the doors open if there's any sign of damp or try any of the other suggestions here. Hopefully a 1960s house will be reasonably well built.