Extending water main

[davphi338]

Hi,

I need to extend my mains water inlet pipe. I am extending my kitchen by 3m so need to couple onto the current mains inlet. We have block and beam flooring so is it just a matter of coupleing up to the old pipe and pushing some new blue water pipe to the rear of the extension under the floor. Will the pipe need insulating in some way because i can see there being a danger of it freezing if it just sits in the void under the block and beam.

Any advice much appreciated.

 

[swidders]

Always best to avoid joins if possible in the water main before the stopcock, but if it has to be done, then so be it. Any pipework in unheated space must be insulated.

 

[davphi338]

I take your point about joints but I don't think there is any other way. If you can imagine the mains water currently comes up under my sink on the rear wall of my kitchen. I am now going to remove that rear wall and move it forward 3m to create the larger kitchen, so have to get the mains water to the new position of the sink.

What sort of insulation would you recommend. Would the normal pipe lagging stuff that you normally put around hot pipes be satisfactory.

 

[swidders]

Yep, normal foam insulation will be fine, which depending on the type of pipe you are using to extend it will have to be sized accordingly (eg 28mm for a 25mm pipe).

You could extend the pipework in 22mm copper instead of having to buy a coil of mdpe, but if you do go for the plastic you may wish to relocate the join to another more easily accessible point which won't cause major disruption to your new finished floor should any problems arise.