Moving CH pipework underground

[mikkymo]

I have an attached garage which has a utility area at the back of it, separated by a freestanding block wall (not supporting anything) and a doorway into the garage. I’m taking the wall down to free up more space in the garage and eventually let me knock through the back to make a ‘drive through garage’. There’s a combi boiler attached to the side wall of the utility venting outside. The CH and hot water pipework runs down the side wall and across the bottom of the block wall, then dips into the floor under the doorway and comes up under the floor of my dining room to feed all the rads and taps.

What are my options for putting the pipework underground? Would I be ok putting speedfit inside a 110mm soil pipe ‘duct’ filled with fibreglass insulation and a thin mortar ‘end cap’ to stop mice? What sort of depth do I need to put it? Would be easy to spot leaks and also let me run network cable through. I don’t need to put any in there, but I’m guessing power cabling through a water pipe duct is a no-no?

Thanks,

MikkyMo

 

[mikkymo]

What about digging out the trench, laying 50mm kingspan into it - floor and sides - installing all the pipework where I can see/get to it easily, then 50mm kingspan lid to close it all off, and concrete on top?

Bound to be more thermally efficient as well as giving me better access while I'm putting the pipes in?

 

[Newboy]

Enclosed duct as per your first suggestion. Use rest bends (longer radius) at both ends and you should be able to slide armaflex insulation over the pipework.

At least 450mm below finished external level.

No to putting power cable into the same duct!

The obvious question - what are the pipe currently run in and why do you need to change it?

 

[mikkymo]

Thanks for the reply!

Stupid question, but I take it when you use the rest bend you'd just install the plastic pipe with no elbow joint?

Is HEP a better choice than speedfit for CH?

Pipe is currently 22mm copper, clipped to the wall which is going to be removed. Changing to plastic underground in a duct as I need to run the pipes across the width of the garage.

 

[Newboy]

http://www.screwfix.com/p/87-5-doub...rch-_-SearchRec-_-Area1&_requestid=216443#_=p

Personal preference would be speedfit

http://www.screwfix.com/p/jg-speedfit-22bpex-25c-barrier-coil-pipe-25mx22mm/12600

Put a draw rope into the duct and use it to pull the insulated pipework through - make sure you protect the pipe ends against scaring as you pull them through.

http://www.screwfix.com/p/stranded-polypropylene-rope-blue-6mm-x-30m/98570

And make sure that you don't destroy the DPC (assuming that there is one) in the floor

 

[mikkymo]

Oh bloody hell - brilliant! Thanks very much for the links as well!

Cheers,

M