tap the wall with your knuckles to identify where the studs are, and compare this to where the radiator brackets go. Your battens or piece of ply needs to bridge at least three studs unless there is some good reason why this is impossible.
I suppose if you were to get a piece of ply in advance, cut to size, you could even paint it to match the wall and have it ready for the plumber. I would probably use 12mm ply which you can buy in various sizes at DIY sheds and places that sell wood.
the top of it need not be higher than the rad brackets, and it can be a bit narrower than the radiator, so it will not show. It must be at least big enough for all the brackets to screw into it.
Have a look at all your other rads and see if any others need doing.
I suppose if you were to get a piece of ply in advance, cut to size, you could even paint it to match the wall and have it ready for the plumber. I would probably use 12mm ply which you can buy in various sizes at DIY sheds and places that sell wood.
the top of it need not be higher than the rad brackets, and it can be a bit narrower than the radiator, so it will not show. It must be at least big enough for all the brackets to screw into it.
Have a look at all your other rads and see if any others need doing.
