Central heating pipes in dot and dab wall

[Tuttle]

I am building an extension on my house. The downstairs room has a concrete floor, cavity brick/block walls and I am planning on dry lining the walls using dot and dab. This room will have a radiator under the window and I have just realised that I don't know how to run the central heating pipes to this radiator. The pipes will need to run down the wall from the ceiling. In existing rooms I have pipes running down the corner of the room, boxed in, but I assume that I can do something more clever in the extension.

How can I conceal the central heating pipes in the dot and dab wall? Is copper or plastic pipe better for this - the rest of the plumbing in the house is copper, I have a reasonable amount of experience with copper pipe but no experience of plastic pipe. I assume that the pipes are normally run down the wall and then the plasterboard is fixed on top? Is there anything special that I need to do to insulate the pipes, eliminate noises as the pipes heat/cool, protect the pipes from the dot and dab, etc?

Any tips welcome!

Thanks

[Simon F]

Hello,
if your using copper you would need to protect it from contact with the plaster, adhesive, wall etc.
If using plastic cover with a foil tape so that it can be detected.
best to avoid joints where there will be no access, so 10mm copper tube or plastic cut from a coil

[Bernie2]

Have a look at the guide to the water regulations they are a pretty good guide for access to pipe methods or look up something for timber framed houses. Usually all it amounts to is being able to get at them at a later date and stopping them freezing. If say you used 15mm pipe and run them down an internal wall from the floor above to underneath a suspended ground floor. You could sleeve them in 22mm pipe behind the plasterboard so that you could replace them in one piece if they burst. Also there are some guides to insulation of pipe on exterior walls.

[gasmanrob]

right ok this will upset a lot of plumbers on here but should achieve what you want depending on your existing set up.

Run your pipes in the ceiling void as normal then about a foot before you want to drop down the wall change to 10mm plastic. chase out the wall where you intend to run the pipe and that should allow you to dot and dab over the top of them no problem. i would use plastic as this will allow a continued run of pipe from ceiling to rad valve with no joins so reduced chance of a leak in the wall.

if you work out the middle of the window then come up between 12-18 inches from finished floor level fix a metal patrice box with grommets to the unfinished wall and use this to bring the pipes from inside the dot and dab to the outside and leave yourself enough excess pipe to reach the radiator valve.

(tip the pipe that enters the left hand of the patrice should go to the right hand rad valve and right hand entry to the left hand rad valve) it is easier to manipulate the pipe this way rather then trying to force the pipe to bend in away it doesn't want to.

also to enter the patrice it might be easier to make a heart shaped loop around it to get it in without kinking the pipe but you will know what feels right when your putting it in hard for me to say as i don't know the space available to you.

But rad valves that have a 10mm elbow in them already and this will allow you to just push your 10mm tails straight into the bottom of the valve.

good luck.

[stevetheplumber]

common practice on newbuilds

[Tuttle]

Hello,
if your using copper you would need to protect it from contact with the plaster, adhesive, wall etc.
If using plastic cover with a foil tape so that it can be detected.
best to avoid joints where there will be no access, so 10mm copper tube or plastic cut from a coil

I like the idea of using 10mm copper, mainly because I am more familiar with copper. How is it normally protected?

I was thinking about using spiral wrap (Spiral Wrap 50mm x 7.5m | Screwfix.com) as it looks quite thin and I guess could lag the pipes and also protect them at the same time.

[woodytheplumber]

use 10mm copper if your radiator is under 10,000btus but buy a role of 15mm and sheeth it in that bring your pipes out in the center of the radiator and put a m/f elbow straight into the valves and pipe from behind

[Tuttle]

Thanks guys.

I notice that screwfix do PVC coated 10mm copper pipe (PVC Coated Copper Pipe White 10mm x 25m | Screwfix.com) so I think that I might give that a go

[AWheating]

10mm copper will be a good choice, what size radiator is it? you should be fine upto 2.5kw output (at 11degree difference) increase to 15mm in floor/roof space.

[Tuttle]

10mm copper will be a good choice, what size radiator is it? you should be fine upto 2.5kw output (at 11degree difference) increase to 15mm in floor/roof space.

It's only 1.1kW so 10mm should be fine. I'm a little concerned about stories I've heard about blockages in microbore pipe but I don't think that I'm going to let that put me off ... I'm thinking if 8mm can be used on radiators then 10mm shouldn't be a problem.

I'm still a little undecided on the details - what to protect the pipe with and where to run the pipes to - but I am leaning towards 10mm copper pipe inside 15mm plastic as this leaves room for expansion and then running the pipes to the radiator valves, coming out of the wall just below the valve on each side of the radiator. The alternative seems to be running the pipes to a box behind the radiator, and then out to the valves, but that feels like a bodge to me (maybe I'm just being fussy though, or maybe this is actually standard practice).

The radiator is about the same width as the window so it shouldn't be a problem running the pipes down each side of the window.

I've spent quite a while Google'ing for information and haven't turned up very much at all, which surprises me as this must be quite common practice in modern houses.

The only other thing that concerns me is if I remove the radiator at a later date, e.g. to redecorate the room, leaving the valves on the ends of the 10mm pipe sticking out of the wall then how likely is it that the 10mm pipe will get damaged? Standard 15mm pipe is quite robust in this sort of situation but I'm not sure how strong 10mm pipe is and how easily it would be to damage it, e.g. if the valve were knocked while redecorating (I have not used anything less than 15mm before and I haven't got any 10mm pipe yet).

[Dannypipe]

10mm copper tube is easily damaged. 10mm plastic pipe is tough, and won't be easily damaged.

I've done exactly as was suggested by 'gasmanrob' and not had an issue. Sure it's not ideal, but as he says - look at the opening on some rad valves. The appature on some is about 8mm.

You can't just throw 10mm everywhere and hope it works!!

But in this instance I think you'll be fine.


Also you can buy purpose made inset boxes from Toolstation to direct the pipe. A single patress with grommets is a good idea, but these things are purpose made.

[AWheating]

plastic into a box or face plate is fine aslong as the radiator is not very small, never like the way the rads can be pulled off there brackets by young children on most new build installs.

[Dannypipe]

Very good point.