It's a bad idea to do anything until you address the moisture issue. You may be rotting your roof, attic, or insulation.

We had the walls tested and we were told they were not damp. I don't know whether the dampness is caused because there is no heating in there although we are having radiators/heating connected before we have the work done. We don't get wet patches just blackness through the wallpaper.

Are you sure the blackness isn't mold?

There is clearly a condensation issue that will need to addressed. Have a roofing contractor look at it to see if vents need to be installed. I would not do anything until this is done.

If wallpaper doesn't stick there is a problem. Tiling it is not resolving a problem that could cost you dearly in the long run- health wise (moulds are not good for you) and financially - taking down all the tile work to fix it.... Do insist on this first....

"Blackness" sounds like mold. There needs to be a serious amount of moisture trapped in the attic space behind your walls to make wallpaper fall off and mold form. Are you paying for your heat and is your heating season long? Your reference to a bedsit says England, though you could be almost anywhere. If you are in a flat, is the heat supplied by the building? Because a steam fitting allowing this much moisture to condensate is a possibility. Unless a roof leak is pretty large, the amount of condensation you relate is impossible, even an unvented attic will not show this amount of moisture due simply to heat and cold moving through the roof and moving the dew point inside the structure. It takes years to have any noticeable effect. A large roof leak would have been noticed in the living areas below, as it would pretty much rain in the house.

Thanks you alll for your advice. The attic room is on the top floor of my house, it is not a flat. The rooms below are gas centrally heated. It is the outside walls only that have the damp problem and the chimney breast. I do have a dehumidifier running in the room at the weekends when I am home from work. As previously stated I will be having gas central heating installed in the room within the next few months. The roof is sound as the whole house has been re-roofed only a few years ago and there is no sign of any water marks. Perhaps I should get the builders back in.

Hi Brenda, we've had several types of damp in our Victorian building, for what its worth heres a few suggestions that helped us:
Use binoculars to look at your roof/chimney, check for lost tiles and lifted flashing/bird nests/blocked gutters/old paint/old porous brick,/old windows and sills or sealant around them cracked.

Those jobs need doing first, and could be cheaper than you think.

Is your chimney blocked below or vented to let a draught through?

Are you attached to someone else and/or share a chimney?

Do you have a water tank or any internal pipes up there?

We've had great success using Wallrock thermal lining paper, its expensive, difficult to cut and you have to line over it with wallrock fibreliner, but boy does it make a difference to the temp of the walls and room, but we made sure to get all problems sorted out first.

Do the walls in your top room get very cold?

here's a few photos just to show common problems , hope this helps you spot something on yours that might explain it. Best of luck :)))

The chimney damaged and how it should look

few more ....

valley guttering between two buildings, and other rot/ age/weather damage

blocked roof vent

Thanks for your advice. Surprisingly we are having Wallrock put on the walls next week. We have had central heating fitted now and the room appears to be over the damp period. Looking forward to getting it all completed.

oh that's great news!
We bought the proper knife to cut it with, when wallpaper scissors, stanley knives and scalpels didn't work, it was less than £10 but it made all the difference, saved time, frustration and bad language. :)))

http://www.gowallpaper.co.uk/ofla-heavy-duty-x-design-auto-snap-knife-18mm.html

best of luck

ps the thermal liner can dent, so don't let the decorator lean heavy tools against it :))

Just had the Wallrock thermal liner delivered, they gave us a free knife too which was great. Did spend over £400 on it though as decided to do all the outside walls in the attic and living room too. Hopefully it will be worth it.

Interested in the outcome , after the liner has been fitted

I have been in Goa for the last 3 months bu I shall be returning within 2 weeks so will let you know the state of my walls when I return after leaving the house unlived in for 3 months. I did leave the heating on a low setting though which I am glad about as the weather seems to have been very cold whilst I have been away.

I am now back in the UK and my house has survived the cold and snow whilst I have been away for 3 months. The attic is much warmer and no sign of damp. Well worth the money spent.

Very pleased for you , all the best Graham