What is the regulation for running gas pipes vertically up timber kit walls. Is it allowed and if so, how? I have just bought a small flat and I need to run a gas pipe from my meter which is situated in the corner of my living room into the attic where there will be a new boiler installed. I dont want to have it surfaced with the need to box it in afterwards, hoping to rather remove the plasterboard from the timber kit wall and run it up the wall in the back of the plasterboard, into my attic to the boiler. Many thanks in advance.