It is not necessary to hang wallpaper to cover the entire wall behind a radiator.
If you want to cover the complete area, it may be possible to lower the radiator
and rest it on the floor below.
Then remove any old wall covering, size the wall and paper the section in the same
way as the rest of the room. Allow the paper to dry for a few hours before replacing
the radiator to its original position.
If you are not lowering the radiator, allow the lengths to cover approximately 150mm
(6 inches) behind the radiator. This will allow sufficient space for pushing the paper
smoothly onto the wall and removing any bubbles. This also allows the wall to be covered
enough so that the wall behind does not show.