Pipes under floor Question.

[PeTe33]

Before Winter bites hard, I need to get my downstairs (bedrooms/bathroom)heating sorted. (It doesn't exists at the moment)

Original 70's pipework was buried in concrete floor so I am to run new pipes above surface. Only prob is there are 2 areas where pipes need to go across hallway so sub-surface.

I appreciate I will need to put pipes in some form of ducting with lid, but can't find anything that would be suitable as a load-bearing, removable lid, floor ducting.

If anyone can point me in the direction of a suitable solution to my problem I would be most grateful.

Cheers Pete

[vince]

Dig out a larger trench that you need and line it with timber with a rebate at the top of the side pieces to take a timber lid say 12mm MDF which can be screwed down.

Vince

[Rick]

3x2 as the sides, and a plywood top ?

Rick

[The Natural Philosopher]

No need for that...use some underfloor heating or other flexible plastic pipe, and if worried about insulation, stick some foam round, and just concrete it in. You might want to stick a bit of chicken wire in the trench as well for mild reinforcement..

You can then go back to copper either side of the 'tunnel'..or not..

[PeTe33]

Hmmm. sounds a bit complicated with lots of copper to plastic and back. I think the timber box idea will more than suit my requirements. It also needs to house the DHW & Cold to bathroom too.

Thanks for all suggestions - far simpler than I was trying to make it.

:¬)

[Vortex]

I did this about 10 years ago.

Purchased a length of purpose designed UPVC channeled trunking from local plumbers Merchant.

I cut a channel, mortared the trunking into it, and it has a 9mm ish plywood lid.

David

[TheScullster]

Watch out for heat take up between piping. I saw a diagram recently which showed an insulating barrier along the length of a similar tunnel to separate the mains cold feed from heating and hot water pipes. Otherwise when you want "cold" water you need to run off a leg that has warmed by conduction from heating pipes!

Phil

[PeTe33]

Thanks David. I had seen uPVC stuff but didn't think it would be suitable from a load bearing poit of view, I didn't think about the support it word get from sand/cement.

Cheers Pete

[PeTe33]

Indeed. I have used this side-effect with relatively good sucess by making a heat transfer thingy between the C/H return from a small C/H circuit (1 towel rad) and the hotwater leg in the kitchen.

the kitchen hot is turned on you get a few seconds of cold then about 20 seconds of warm water, then another cold bit untill combi flow gets to the tap. With an additional heat exchanger I could eliminate much more of the cold leg of the kitchen hotwater feed.

Certainly good for the quick rinse of dirty hands, and getting warmer water to the dishwasher on first fill.