Cutting into 15mm behind drylining for softener valves

[davidr]

Hi -

I want to fit a water softener into a standard kitchen cupboard adjacent to the sink due to lack of space directly beneath the sink.
Access to waste, overflow and power is ok. Rising main to loft header tank is more difficult as it runs horizontally behind the drylining in parallel with a return hot feed. Access is limited as I'll be working under granite worksurface and "through" a 500mm base unit.

If I remove a piece of drylining 300mm by 88mm to expose the pipes, how would you recommend cutting the cold pipe (hacksaw?) and fitting the valves ? I was hoping to slot the valves in line in a 9 inch gap cut in the pipe with valve bases against the brick.

Does this make sense or would you solder elbows to bring the pipe out from the wall for more access and clearance? I've got fairly high pressure and want very secure and well supported joints.

Thanks

 

[glasgowgas]

View media item 11886

 

[mrgas]

Why on earth 88mm?
Make a neat hole as large as necessary to carry out the work.
88mm !!!!!! Not even a gynocologist could work through such a small opening.
500mm Unit.
At least 350 by 350mm

 

[dextrous]

Why on earth 88mm?
Make a neat hole as large as necessary to carry out the work.
88mm !!!!!! Not even a gynocologist could work through such a small opening.

Not quite sure I agree with this

However, op, he is right - give yourself plenty of space to work in.

As for cutting the pipe, without knowing how far it is running away from the wall, how can anyone advise? Ideally a pipeslice would be best and easiest if there's room to wrap it round the pipe.

 

[mrgas]

A big hole is just as easy to make good as a small one, and a lot easier to work through!

 

[davidr]

Why on earth 88mm?
Make a neat hole as large as necessary to carry out the work.
88mm !!!!!! Not even a gynocologist could work through such a small opening.
500mm Unit.
At least 350 by 350mm

88mm was a typo - I meant 80 mm. Idea was to cut a letter box shape directly over the pipe exposing enough copper to splice in two t-pieces and the bypass valve with compression fixings.

A big hole is just as easy to make good as a small one, and a lot easier to work through!

Thanks for the advice - I'll cut a bigger hole in the plasterboard. Back of kitchen unit pulls out easily to reveal plaster board wall.
However, the copper is hard up against the brick, currently sandwiched between the plasterboard and the bricks - so no room to get circular pipe slice around the pipe. Is there a good tool to make a clean accurate cut or should I just use a junior hacksaw blade?

Sorry to be so pedantic over this but this is the high pressure feed to the cistern and if I get this wrong I could end up having to remove baseunits and granite in a worst case scenario.

No picture yet - haven't made any holes yet.

Thanks

 

[JohnD]

I am a householder not a plumber, but I would cut away enough plasterboard to expose the next pipe clip or two, then pull the pipe away from the wall enough to get my pipeslice round it. Copper pipe will bend and spring enough to do that. Do not put stress on any joints though, in case you make them leak.