Chasing a brick wall.

[rob_j20]

I have a cavity brick wall i need to chase for running central heating pipes to upstairs.
I'm pretty sure the wall is non load bearing, its the end wall of the house so the joists aren't on it, am i right in thinking i can take upto 1/3rd out so for standard bricks around 34mm.

Is there a limit to how wide the chase can be? I plan on running two lots of 22mm through conduit, plus another 2 15mm through conduit and 2 lots of 25mm conduit for network cables.
Is it best to leave a gap between the chases, im guessing putting them in pairs will be okay.

 

[23vc]

That's a hell of a lot of chasing with the resulting dust and mess, if you're dot and dabbing it then you could make use of the gap behind the boards to take less out of the brick. Assuming it's copper pipe you could protect the side against the brick with a strip of DPM or plastic and do away with the conduit.

 

[rob_j20]

No it will be getting plastered, Hardwall and multi finish. Hep2o pipe.
I plan to drill a line of holes then use the sds to finish it off hopefully not too much dust especially if I get someone with a vacuum.

Just hoping structurally is a sound plan.

 

[Doggit]

Being Hep2o, it's going to sag, and be sitting against the brickwork in a lot of places, so really needs insulating, and that means you've got to chase into the wall about half the brick depth. I'd be inclined to suggest that you only chase the wall about 30mm, and then batten the wall and add plasterboard. You might get away with copper (being thinner), and use pipe wrap and then duct tape to secure it, before fitting the pipe.

 

[rob_j20]

Can't do that, there is a door at a right angle to the wall so can't bring the wall out any further.
The run will only be 2.4m. Surely the pipe in pipe would be the same and you would have it in contact with the brickwork /concrete. I plan to go about 25mm deep the plaster being about 15mm should hide the pipework then.

 

[23vc]

I'd not bury plastic in the wall if it's to be solid plastered, as for reasons you state above you'd have to conduit it and with 22mm pipe makes for a ridiculously deep chase.
If I absolutely had to bury pipe and couldn't plasterboard it, I'd wrap copper completely in tape and chase at least an inch back from the surface. Had a nightmare before when I chased it too close to the surface, heating came on and cracked the whole run, ruined a lovely plastered and painted hallway...

 

[rob_j20]

I'd not bury plastic in the wall if it's to be solid plastered, as for reasons you state above you'd have to conduit it and with 22mm pipe makes for a ridiculously deep chase.
If I absolutely had to bury pipe and couldn't plasterboard it, I'd wrap copper completely in tape and chase at least an inch back from the surface. Had a nightmare before when I chased it too close to the surface, heating came on and cracked the whole run, ruined a lovely plastered and painted hallway...

That's the plan all along I have Hep20 conduit, should reading the regs I can go a 1/3rd into the brick which is 34mm plenty to bury the conduit, plan to use mortar in place of plaster then skim it, should avoid any cracking and slow new to go thinner.
Not much else I can do, I don't like the idea of copper as it would need a join.

 

[Doggit]

The mortar will still heat up, and crack the plaster skim. You at least need to use the pipe wrap to cut down the heat transfer, and that'll mean going in deeper. A copper joint done properly, won't be an issue,

 

[rob_j20]

I may try and run the 22 a different way, currently the central heating goes up somewhere by the chimney in 15mm, presume there used to be a back boiler. See if i can push the conduit and pipe down there. The DHW and a cold water for the bathroom will need to be chased into the wall, but the 15mm conduit looks much easier to bury.

 

[23vc]

Cant you box the chimney section out sideways by another couple of inches and run the whole lot down there? Assuming it's all getting skimmed

 

[rob_j20]

Not really, there is another door there. I have looked at all sorts of ways and short of running pipes all to the other side of the house or having a big obvious boxed section the only way is to chase them in. Another idea i had was to chase them in shallow and cover with some thin ply screwed to the wall over the pipes, it would then be wallpapered. Not sure how that would behave though, but i could then get away with only removing around 20mm or so of brick.

 

[23vc]

Avoiding the 22mm will make things easier then. As said above you could include soldered copper joints if you wanted to go the copper route and do away with conduit. Ply and wallpaper sounds horrible. Good luck

 

[rob_j20]

Thanks for the advise guys, i will keep looking for some other route for the 22mm runs.
Would putting a good size bit of plasterboard over the pipes instead of hardwall/mortar help with avoiding any cracking.

 

[23vc]

No, just keep the conduit as far back from the surface as poss, fix it well to the brickwork and hope the conduit itself doesn't expand enough with heat to cause any issues

 

[Gossamer]

I'm doing my kitchen soon and have already decided not to chase any pipe work and box it in. If well done at the right location no one will know....