How to run heating and water pipes in new extension with solid floor

[ChrisYork]

Good morning guys,

I’ve currently got some building work going on at home and it’s nearly time to run the heating pipes. The builders are laying a floor which will be hardcore, then sand, then insulation, the dpm and finished with concrete.

My query is about the heating pipes. They’re talking of cutting out a channel in the insulation and running the pipes in this. My concern is that is this correct and if so what is the correct way to do it? The problem I see is if a heating circuit is run under the concrete and dpm, holes will have to be made in the dpm to bring the pipes up and also T pieces will need to be installed underneath the concrete.

Thanks in advance!

 

[Ben-gee]

It is normal to run pipes in the screed, so above the final DPM. It depends a bit on the exact make up of your floor, but from what you have said- pipes should go in concrete layer.
It is better if a channel is left, and better still if this has a removable top for future access.i.e. Channel in concrete for pipes, with timber rails set in the concrete such that an 18mm ply cover will finish flush with the concrete level

 

[Pickwickpick]

Yep as @Ben-gee says it's normal for it to be laid in the screed, not underneath it, as you say if it's underneath the DPM the DPM won't work properly.

 

[ShaunCorbs]

You could lay them directly in the screed insulated mlcp pipe or normal copper and taped insulation

 

[Ben-gee]

Agree with Shaun, and this is what normally happens. However at last home extension I used a covered trench for pipes, and when I later had to make some alterations I was very glad of this method!

 

[gmartine]

As above you can use/purchase screed ducting to make life easier.

 

[Ben-gee]

Home extension and purchase never go together well, if you can make it for “free”! But yes on a proper paying job I agree.

 

[ChrisYork]

Ah thanks for the speedy response guys. I thought putting it underneath the dpm wasn’t right. Also if you cut out the insulation to accommodate the pipes there’s going to be very little insulation between the pipe and the sand/hardcore layer underneath.