Conduit Under Garden

Puntoboy

I need to run some Ethernet cables out to the garage of our new house. I am planning on running them from the loft, out through the soffit and down the side of the house to ground level then through some conduit underground to the garage. I need to find a junction box that will fit some 25mm conduit I plan to run underground for the Ethernet cables to go inside. The problem I'm having is finding one that allows me to connect 25mm round conduit from the soffit (using on of the 25mm adapters Tower Female Adaptors 25mm Black Pack of 2) and some ducting for underground. Not sure what type of ducting will be best.

I've considered fibre, this is not an option at this stage.

noiseboy72

25mm twinwall ducting should be OK, provided it's not too long a distance, as the pull might get quite hard with 2 cables in that size. You could go up to 50mm if that's the case.

I would suggest you get some plain waterproof boxes and drill them to suit. If you need to terminate them in the box, use back to back connectors and ordinary Cat 5/6 connectors wrapped in electrical or amalgamating tape. This will keep out the worst of the weather.

Doghouse Riley

I ran several mains cables from my garage to our summerhouse 30 yards away. I used alkathene waterpipe rather than conduit and buried it 9" below the side fence.
It's flexible and "spade resistant."
It's been there for forty years. Never been a problem.

Puntoboy

I can’t find 25mm twin wall. Although I will be running about 4 cables. In the current house I use 25mm round conduit down the wall which was big enough for 4 cables. Smallest twin wall I can find is 32/40 (id/od).

noiseboy72

I would go larger in that case. The water pipe suggestion is good, not thought of that.

mickevh

If there's space, you might care to leave a "draw string" in situ, in case you ever need to pull in additional or replacement cables in the future. I know the cabling guy's I've employed all say a silent prayer of thanks whenever they find one left by a predecessor.

The "proper" cabling guys here can hopefully advise what such things are made of - I presume it isn't literally a length of hairy string as one assumes such would rot over time - I'd guess they are some form of synthetic or plastic....?

Puntoboy

From my experience it’s just a blue nylon draw cord like rope. But yes I’ll be adding a draw cord. Also I’ll be running 4 cables so I have a spare or two as well.

noiseboy72

Probably worth thinking about what cable type you use as well.

Common sense would suggest proper external grade cat5 or 6, but I've been running gigabit speeds down 30M of basic Cat5E UTP tacked to the side of my house and along a fence into my man cave for 15 years without any sign of degradation.

Kristian

If you're hoping to pull cables through in the future then you'll need 50mm minimum.  If you can pre-feed the cables in before you install/bury the conduit then you might get away with smaller diameter.  As soon as the conduit is in the ground there will be many slight bends and turns which will make pulling new cables down it really difficult, if not impossible, on smaller ducting.

Will this do the job?  It is IP65 and 20/25mm holes - Adaptable Box IP65 110 x 110 x 67mm

Or find some other outdoor junction box and use a 25mm hole saw.

I'd be using outdoor grade Cat5e/6 as well.

Even if you use fibre, you might want to duct it.  Or buy armoured and direct bury it.

Puntoboy

It'll be external grade CAT6a although I may put in 7 for just this run. I will be ruining 10GBe.

So I think I'm going to go with 32/40 twin wall ducting. 25mm conduit down the wall. The issue I am having is finding a suitable junction/adaptable box. The 40mm ducting is larger than many will accommodate. I have found this one but it's grey and I need black (I guess could paint it?) Hellerman EL171 Junction Box 175x151x95