Hi guys, 

Doing my extension and the foundations are in as are the blocks upto floor level. Hoping to get the slab done next week. 

 

Im planning to run two lengths of 25mm mdpe blue pipe through the hardcore that goes under the slab and out through a gap in the blockwork. 

 

One will be a conduit for running an electric cable out in the future so we can have power in the garden. This will come up by the fuse box.

 

The other is to allow a water supply to the garden. This will.be connected in just after the stop cock. Is there any problem going 15mm (main feed)  25mm (under the slab)  15mm (outside tap). 

 

Was just wondering if this sounds ok? Or if I'm missing anything? 

 

Thanks

Paul

 

 

 

No problem changing sizes of water pipe, and as its under the extension unlikely to freeze even with the shallow depth

Sounds ok to me, just make sure you put a draw cord in for your cable before it’s installed.

Edited April 9, 20215 yr by joe90

No problem until someone decides to join into the ‘water pipe’ cuts through it after turning the water off and gets electrocuted

 

all for ducting , but you would be better off with some 50mm flexi dusting designed for the job.

Don’t use MDPE for the electric - if you need to put a duct in now, use grey or black 32mm poly waste pipe as it’s cheap and easy to lay and much better for the long bends at either end. 
 

Using blue MDPE is asking for issues and it’s not that big internally. 

Sounds shit to me with a capital S 

 

as has  been said 

 

DO NOT RUN A POWER CABLE THROUGH A PIECE OF MDPE , unless of course you are a complete fool. 

Run the power cable in an appropriate duct for electric, it is pennies in the grand scheme of things. 

Nobody will hack through a duct without asking themselves what’s in this, whereas a bit of blue poly I would just hack through it with a mattock and kapow 

 

surprised at some of the people above who think this isn’t a silly idea. 

41 minutes ago, Russell griffiths said:

Sounds shit to me with a capital S 

 

as has  been said 

 

DO NOT RUN A POWER CABLE THROUGH A PIECE OF MDPE , unless of course you are a complete fool. 

Run the power cable in an appropriate duct for electric, it is pennies in the grand scheme of things. 

Nobody will hack through a duct without asking themselves what’s in this, whereas a bit of blue poly I would just hack through it with a mattock and kapow 

 

surprised at some of the people above who think this isn’t a silly idea. 

Come on Russ 

You need to say it how it is ?

On 09/04/2021 at 13:08, Russell griffiths said:

Sounds shit to me with a capital S 

 

 

Thanks for the feedback although I think it should be with a lower case S as half my question/plan about the water side was ok ?

Its also the reason I was asking so I could get feedback as I wasnt sure if it was a good idea, I have a lot of the blue pipe spare and as it will be under a slab, hardcore, insulation and screed and would terminate where it came out the  blocks/wall I didnt think anyone would come across it in the future, but you never know.

Happy to run something else in though. Would this be ok
https://www.screwfix.com/p/tower-corrugated-conduit-20mm-x-10m/50443

Whilst im thinking of future proofing and hiding cables/aesthetics. The kitchen island will need power, am I better running this under the slab (or at least a conduit with draw cord), or above the slab and within a conduit in or in the insulation, both options have been suggested to me.

Thanks for all the replies, really helps to clear the mind and set me on the right path even if my ideas are sh*t ?

Paul

20mm conduit snags cables and it’s tiny inside - just use black or grey 32mm waste pipe. Cheap as chips and near impossible to damage. 

AHH yes will get some of that.

 

Should I use that under the concrete for the kitchen island too? Or wait and lay it above the slab?

5 hours ago, hotnuts21 said:

AHH yes will get some of that.

 

Should I use that under the concrete for the kitchen island too? Or wait and lay it above the slab?

Lay it above the slab to the kitchen Island. The less times you puncture any waterproof or radon layer the better. Also less chance it gets damaged or cut back and forgotten during construction of left till later

Edited April 11, 20215 yr by Dudda