How To Chase A Wall For Microbore Pipes??

[Whitespirit66]

I need to add a radiator to a room with 10mm microbore from a manifold in loft above. The walls are plastered breeze block. The plumbing is no problem, but I have never chased a wall before. Can anyone tell me;

1) Whats the best tool to cut the 2 parallel lines in the wall for the sides of the channel - a chisel or can I use an angle grinder with a masonary disc?

2) Can I chase out between the 2 lines with a cold chisel or is breeze block too hard for this?

3) How do I secure the pipes in the channel - plastic 'Talon' clips seem too bulky?

4) Do i cover the pipes with the type of plastic/metal strips that cables are normally covered with?

5) What materials do I need to fill in afterwards?

Hopefully I can do this without buying expensive special tools.
Many thanks

 

[CyberStGeorge]

If you have an angle grinder by all means use it.
You will get a serious amount of dust though.
Seal area off with sheeting or plastic. You will need gloves, goggles and mask though. Cut until you can see no more then step out until dust settles before going back into enclosure.
Personally I would use a bolster. Harder work but less dust and probably quicker in the sense that you can carry on without the need to step out of an enclosure.
You do not need to chase out the breeze bock as the plaster should be more than 10mm thick, with the browning coat and the finishing coat.
If these blocks are celcon then a bolster will easily cut into them.
To secure the pipes use larger headed galvaised clout nails either side of the pipe, 40mm length should do.
If the blocks are conctrete nail between cement courses, not into the block.
If they are Celcon then you can nail straight into the block. Cement course if good would be ideal though.
No need to cover pipes, but can use metal channel if u like.
Fill in after with Plaster Bonding, not Browning leaving 2mm to apply either multifinish or filler to be sanded.

You do not say the year house built in.
Always handy to give so that people in the know understand limitations.

 

[oldhenry]

I found ,when I did this some time ago, that eventually, the heat shows through on the wallaper. This may be a feature of the wall paper. The original builder in my 1977 house put plastic cover over the m/b pipes- the sort used to cover electric cables before plastering, none were chased into the blocks, but sit on the surface and are covered by plaster. But this is very thin on the pipes/plastic and , as I said , heat shows through.

 

[seco services]

No need to cover pipes, but can use metal channel if u like.

if you follow the water regs you do.

 

[CyberStGeorge]

If this is a 77 house they could well be Celcon blocks which were designed to be light and give good insulation due to the air trapped in the block. These are easy to chase with a bolster. Do you know if these blocks are concrete or not?
Have you tried a bolster on them before?
Do not use plastic channel on microbore.
Use metal if anything.
I have never had problems with my microbore. It is 8mm though and I do not use wallpaper in my houses.
Also I drop both pipes down together and then branch off.
Also wherever possible I use the corner of the wall and take the pipework behind the skirting.

 

[CyberStGeorge]

No need to cover pipes, but can use metal channel if u like.

if you follow the water regs you do.

on what basis

 

[sooey]

No need to cover pipes, but can use metal channel if u like.

if you follow the water regs you do.

on what basis

If you don't cover the pipes they can be corroded over time through being in contact with plaster or mortar. If you use a metal channel the copper and metal can react with each other through electrolytic action, again causing corrosion to one or the other depending on which metal is used.

 

[CyberStGeorge]

So your saying the regs say that galvanised metal channel can cause corrosion on the copper and only plastic is suitable. This means that the pipework cannot touch the wall, (walls contain salt etc which will corrode the pipes) that is the reason copper pipes should be protected by a sleeve when passing through a wall. The pipes should be clipped away from the wall. So Whitespirit66 should allow 10mm for the pipe, + 5-10mm for the back of the clip. a further 3mm for the plastic channel + at least 5mm for the plaster.
Total 23-28mm depth to the face.
I suggest he hires a kango.
Plastic is totally useless when it comes to plastering over, as 'in time' it will crack as the heat will cause the plastic to move.
Who thinks of these regs anyway?
As for corrosion I have never had pipes corrode in 25 years or heard of copper pipes corroding under these circumstances.
I just love Regs people

 

[Whitespirit66]

Thanks for the replies so far.

To confirm;

The house was built in 1961

I'll be using plastic 10mm pipes.

 

[CyberStGeorge]

LOL
Well go with what I said then.
Do it quick before a regulation man gets you.

 

[sooey]

So your saying the regs say that galvanised metal channel can cause corrosion on the copper and only plastic is suitable. This means that the pipework cannot touch the wall, (walls contain salt etc which will corrode the pipes) that is the reason copper pipes should be protected by a sleeve when passing through a wall. The pipes should be clipped away from the wall. So Whitespirit66 should allow 10mm for the pipe, + 5-10mm for the back of the clip. a further 3mm for the plastic channel + at least 5mm for the plaster.
Total 23-28mm depth to the face.
I suggest he hires a kango.
Plastic is totally useless when it comes to plastering over, as 'in time' it will crack as the heat will cause the plastic to move.
Who thinks of these regs anyway?
As for corrosion I have never had pipes corrode in 25 years or heard of copper pipes corroding under these circumstances.
I just love Regs people

If you read my post, I did not mention a word about regs, water, building or otherwise. I merely pointed out can happen to copper pipe with no protection, or when in contact with different metals. If you don't believe it that's up to you, by the way have you never heard of denso tape. I just love kn*bheads.