shower pipework in cavity wall

[Ouch77]

I'm trying to figure out the best way to get hot & cold water to the right location for a shower room in an extension.

The shower is up against the old part of the house, which consists of a cavity brick wall. Conveniently there's an opening through the wall nearby. Inconveniently the cavity is blocked by an older doorway reveal which has been blocked up.

I really don't want to put a false wall in as we are fighting for millimetres in this space.

The image below shows the layout, S= shower spigots/mixer valve location B = Basin location

The point where the new block infill meets the old brick where you can see the odd missing halfbrick is the old doorway/opening reveal, and is currently blocked across the cavity.

One idea that crossed my mind is if I can punch through that block/reveal and scrape out a brick or two on the right for the mixer valve spigots. I can then drill through the new blockwork at J and rise up to the ceiling and the supply nearby. I can't rise inside the cavity as I'd have a hard job getting through the wall plate.

Is this insanity?

I'd need to make an opening a couple of bricks high in the cavity blocker to give myself enough space to feed some cunningly pre-bent copper pipe through it.

The less desirable alternative is to put a false wall with the shower controls on the window side, and bring the enclosure to the left, this will give me a problem getting the pipes past the floor joist that is against the wall, and it will complicate the fitting of an extractor fan in that wall as well. If so, how much depth should I allow for a false wall?

Any thoughts anyone?

 

[endecotp]

What is your intended wall finish over the bricks and blocks?

Are you averse to cutting chases for the pipes?

 

[Madrab]

+1

You could just rebate the brick and block by 25mm and then run the pipework in that. Any wall finish should sit flat onto that, especially if it's tile

 

[CountryFan]

Surface mount in chrome?

 

[Ouch77]

What is your intended wall finish over the bricks and blocks?

Are you averse to cutting chases for the pipes?

Tile finish on hardiboard or similar.

I don't have a problem with cutting chases (it'll be messy in the old brick given their toughness), but assuming vertical, getting out of the top of the chase will be hampered by the wall plate, Horizontal obviously limits the depth to approx 15mm, which barely allows for insulation.

 

[Ouch77]

+1

You could just rebate the brick and block by 25mm and then run the pipework in that. Any wall finish should sit flat onto that, especially if it's tile

I'd still have to get out of the chase at the top. there's not a lot of guidance regarding notching wall plates for this sort of thing, but (typically) there is a joist in just the wrong place for straight-up chases.

 

[Ouch77]

Surface mount in chrome?

An option, less desirable given our desire for something less fiddly to clean, but probably the last resort.

 

[Madrab]

I'd still have to get out of the chase at the top.

Ah ok, didn't see that. I'd then look to do an small angled notch so it would only be the depth of the pipe, say 20mm and maybe 20mm high and angled out, then just bring the pipes out just above the ceiling transition point, it only needs to be in the plate for the 20 odd mm that it needs for the ceiling board to cover it, if you see what I mean.

If the wall plate is secured tightly to wall all the way along, as it should be, then a little 20mm deep, 20mm high angled slot in it shouldn't trouble it at all IMO.