Chasing 15mm radiator pipes

[bsr]

Hi, any hints & tips on fitting 15mm radiator pipes into thermalite for an extension? I wanted 15mm as the pipes are at the end of a long run so I don't think will balance in 10mm. Walls to be dot & dab over block. Both radiators are to be under windows so my planned route is to go down in the corner of the room, horizontally above the skirting and then out for the valves.

I was thinking of using Hep2O, chasing the pipework about 15mm into the block and using nail clips.

1. For the corners where the drops turn horizontal would you use cold bend formers or elbows (I can chase them in deeper)

2. Where I need to turn from the horizontal runs to go out of the wall into the valve what would you use? If I use a Hep2O elbow part of it would probably be visible. Or I can solder up copper tails with two elbows and use a straight coupler in the wall? or I've seen chromed push fit stem elbows?

3. Would you do all of this at first fix?

4. Do I need to cover the pipes with felt or will the PB adhesive be strong enough to stop the PB cracking?

Thanks

 

[bsr]

Anyone?

 

[Madrab]

1. if you can channel so the pipe's one continual length then that's preferred, so cold formers
2. depends on the finish you want really
3. do all the in wall work as a 1st fix and leave as tails coming out of the wall for the rads
4. If it's plastic and barrier pipe, then usually they would be fine - wouldn't hurt though to wrap to ensure good adhesion for the filler

 

[Exedon]

As a long time new build contractor we would just clip 15mm to the blocks plasterer will be well used to it!
You should really have aluminium tape behind pipes so you can find them with a stud finder.
As long as you use hep or polypipe you can get it to bend round from vertical to horizontal easily.
If the elbows are going to be see maybe use tectite chrome ones?
No dab adhesive should be on pipes

 

[bsr]

@Exedon thanks, I thought 10mm was ok but not 15mm. New builds lol. Yes I have ally tape and I know it can't be stuck directly to the pipes.

 

[Exedon]

15mm is fine behind dot and dab it's only 5mm beyond 10mm
Plus 15 is what's use for h&c and that goes behind dot and dab as well.