Cable management, floor conversion suspended to concrete.

9 Apr 2021
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United Kingdom
Hi I am currently considering converting my ground floor which is currently suspended timber into a solid insulated concrete floor for UF heating. There is a concrete base beneath the joists and the depth from the top of the joists to the bottom of the void (concrete) is 10". Currently the electrics and water pipes are running through the void.

I have an idea for tackling most of the conversion but I'm unsure about what to do with the pipes and cables currently in the void, I read that they have to be sealed into pipes themselves prior to any layers of hardcore, sand or DPM is this correct?

How would you get future access to the cables and water pipes after the underfloor heating and screed are laid?

Does anybody have experience or resources that can help to explain how it's done?

How does diverting services work is it expensive?

Or who I would call about getting a job like this done (electrician, builder, plumber)?

Thanks in advance.

(reposting due to no replies in building section)
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You would ideally relay all wiring in 20 or 25mm round conduit, in singles. I think in reality, wiring isn't very accessible, and faults and changes require invasive work to resolve.

It could all be moved to the ceiling void....

But you can lay UFH over joists, you may need to lower them, but it's absolutely possible.
Round conduit, with singles, installed in a manner where the singles can be rewired, is the best way of course.

Yet you can have T+E in conduit or flexible conduit if you wanted to - it would just mean rewiring in the future wouldn't be possible.

I imagine you want to do this the quick, easy way.

At best, it is very likely you will have to disturb some of the wiring in the walls to do this work.

At worst, it is possible some rewiring will need to be done.

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