Pushfit or compression fittings?

[Adam1991]

Morning all!

Just about to chase some rad pipes into a solid brick wall in the kitchen ready to be plastered over. The pipes come from the loft above.

Its 10mm pipe but i want to make it 15mm so my kitchen fitter has told me to put a 10-15mm reducer and a ball valve in the loft before bringing the pipe down the wall. So heres my questions...

1. All the fittings I’ve brought are compression, would you use these or pushfit?

2. Has the kitchen fitter advised me right here?

3. What would you cover the pipes with once they’ve been chased into the wall?

 

[Madrab]

Why do you want to go to 15mm? If it starts as 10mm then there's no real benefit going to 15mm.

• Compression is fine, you just want them to be accessible
• What are these pipes? If they're central heating pipes then putting isolation valves on them is not a good idea, they're not designed for CH.
• The pipes need to be deep enough, clipped in, if copper they need covered, and depending on where in the wall they are, may need a metal covering plate to ensure nothing can pierce them.

 

[Harry Bloomfield]

If they are heating or HW pipes and you just plaster over them, expansion and contraction will soon crack any plaster. They need some freedom to move.

 

[Adam1991]

Why do you want to go to 15mm? If it starts as 10mm then there's no real benefit going to 15mm.

• Compression is fine, you just want them to be accessible
• What are these pipes? If they're central heating pipes then putting isolation valves on them is not a good idea, they're not designed for CH.
• The pipes need to be deep enough, clipped in, if copper they need covered, and depending on where in the wall they are, may need a metal covering plate to ensure nothing can pierce them.

So theres actually a full setup of 10mm going to a rad but its all on show, the kitchen fitter recommended switching to 15mm and then chasing that into the wall.

The compression fittings are accessible in the loft space above.

Yes they’re CH pipes, again kitchen fitter recommended using isolation valves to knock off the rad should i need to remove it.

More than likely the plasterer will fill in the chased hole with bonding or something similar

 

[denso13]

kitchen fitter recommended using isolation valves

As above, don't use these on CH. The radiator has valves if you need to turn it off for any reason.

 

[Madrab]

If you can switch the pipework from the branch off the main flow and returns up to 15mm then it isn't a crime, just don't see the point if the 10mm pipes are doing the job OK.
You can clip 10mm just as easily as 15mm and the chase wouldn't need to be as deep, you want at least a pipe diameter's depth into the wall from the finished wall surface and cover the pipe to avoid the plaster cracking from expansion.

 

[Adam1991]

If you can switch the pipework from the branch off the main flow and returns up to 15mm then it isn't a crime, just don't see the point if the 10mm pipes are doing the job OK.
You can clip 10mm just as easily as 15mm and the chase wouldn't need to be as deep, you want at least a pipe diameter's depth into the wall from the finished wall surface and cover the pipe to avoid the plaster cracking from expansion.

Only issue i’m facing there is that the whole house is originally 10mm and it goes quite far back so i dont think thats an option. So keeping the 10mm in would be fine? I’ve always had it in my head that 10mm is rubbish and i should go to 15mm. So you’d recommend not doing anything with it and just chasing it back into the wall then?

What would you recommend to cover the pipe with?

Heres what i’m facing at the moment...

 

[Madrab]

Of course 15mm is going to be better than 10mm when it comes to CH piping. If the 10mm pipe is dong it's job though then no reason to change it. No real point in going from 10mm to 15mm if the 10mm is working fine and especially if the rest of the system in fed in 10mm.

If copper is to be buried in plaster then it needs taped to avoid the plaster reacting with the copper. There could also be a capping plate placed into the chase, in metal, if there is a danger that something could be driven into the wall later (screws, nails, tacks etc) and then piercing the pipe.