Hello, I am altering my bathroom and want to install a shower. I need to run the hot and cold water pipes through a stud wall. The issue I have is that the timber is only 36mm wide in the stud wall. I read you can only remove 40% of the stud width according to regulations. This means I can not notch out these timbers as I would need to take more than 40% out of the width.
I can not replace the stud timber as the wall seperates the bathroom and a bedroom and it would mean making a mess of the bedroom as well as the bathroom. I wondered if I can screw additional timber onto the original studs to make the original studs thicker and just leave a gap for the pipes to run through when I put the additional timber on? I thought I could just add 18mm or 20mm wood to the original and this would be deep enough to pass the pipes through. I could then screw new auqaboard / plasterboard through the additional timber into the original studwork. Does this sound like it will be ok? Will it be strong enough? Does anyone have any better ideas how I could solve the problem?
Thanks, Bevo

Hello, I have found I have a bigger problem. The partition is not just a normal stud wall. It seems to be like a prefabricated stud wall that has plasterboard for each side and a cardboard matrix inside gluing the 2 plasterboard walls together. There are no studs to attatch to apart from at the ends of the walls there is the frame and then it looks like this prefabricated wall is just slotted into the frame. Therefore there are no studs to widen!!! I need to have a rethink on how to progress as I can't bury the pipes in this wall unless I cut a channel through the plasterboard and the internal cardoard matrix. I assume this would weaken it. Anybody had this issue before?

Hello, I did think about a false wall but I only have 800mm depth for the shower tray at the moment and wanted to fit an 800mm shower. I know you can get 760mm showers but I would not fit in it!!!! Thanks for the reply though.