Network Cable in conduit under screed

[Tipper]

Why use conduit, any plumbing pipe will do.

I had a detached garage built many years ago and asked the builder to drop in a 'duct' between the house and the garage foundations. He did using 100mm soil pipe. Great until you try to pull a couple of cables through it and discover that he laid it in sections without proper joints and included two right angle bends in the middle to avoid other services! A very difficult cable pull! Also acted like a drain and filled with water too! Carefully check what the builder does...

 

[JohnW2]

But also run the sizes through this: http://www.rm-electrical.com/technical/conduit-and-trunking-capacity-chart/

Interesting. I can but presume that those tables will have been fairly well validated, but I have to say that I am a little surprised that such an approach always work. The implication seems to be that any combination of cables will fit in a conduit of a particular size, provided only that the sum of the 'factors' for the cables is no greater than the 'factor' for the conduit - which, intuitively, I would not necessarily have expected to always 'work' - what do you think?

Kind Regards, John

 

[tvrulesme]

Why use conduit, any plumbing pipe will do.

I had a detached garage built many years ago and asked the builder to drop in a 'duct' between the house and the garage foundations. He did using 100mm soil pipe. Great until you try to pull a couple of cables through it and discover that he laid it in sections without proper joints and included two right angle bends in the middle to avoid other services! A very difficult cable pull! Also acted like a drain and filled with water too! Carefully check what the builder does...

100mm within my concrete slab would concern me structurally. Perhaps unnecessarily. I am going to get these which are super cheap. Also I should be able to get some nice smooth large radius turns using a blowtorch to bend them which I would not be able to do with a 100mm soil pipe.

 

[Echo the husky]

You can make large radius bends with a bending spring, no need to torch anything!

 

[PBC_1966]

You really don't want to go to a blowtorch for bending this type of conduit! Just some warmth from a hair dryer can be quite sufficient to make it easier to form gentle curves, using the bending spring as mentioned.

 

[tvrulesme]

You really don't want to go to a blowtorch for bending this type of conduit! Just some warmth from a hair dryer can be quite sufficient to make it easier to form gentle curves, using the bending spring as mentioned.

I've probably been watching too many people on youtube torching pipe. Hair dryer and spring it is.