Discuss Outside power - shallow depth in the Electrical Forum area at ElectriciansForums.net

Welcome to ElectriciansForums.net - The American Electrical Advice Forum
Head straight to the main forums to chat by click here:   American Electrical Advice Forum

Reaction score
44
So today's job was going to be to run power to the shed. Dig down a couple of foot, line with sand, lay SWA, bury in sand, add topsoil, lay warning tape, rest of top soil, job done.

The actual list of events turned out to be "Dig down half a foot, hit solid chalk, swear a bit, dig the rest of the run to make sure, bugger there's only 20cm of topsoil at the best point, attack it with the pick for a bit, **** this, it's my week off, I'm going down the pub."

I'm now deciding on the best course of action. The trench is across the middle of a lawn that shouldn't be disturbed in the foreseeable future, but I'm still not happy with just laying SWA at 20cm or so. I'm also really not too enthralled about getting down to a couple of foot with a pickaxe across the whole run.

At the moment I'm tempted to make sure the whole lot is at least 1 foot deep, lay PVC conduit, concrete it in place then run T&E. I'm pretty confident that counts as at least equivalent mechanical protection compared to SWA. (Or at least, good luck getting a spade through it!)

Would that be a reasonable thing to do, and if not has anyone got any better ideas?
 
You would want a mechanical digger for solid chalk and it will still take ages.
Your method with warning tape would be OK, but T&E down PVC conduit? not the easiest or nicest, I would tend to go for H07RNF flex down ducting.
Alternatively you could use cable protection cover boards or strip over the SWA.
 
Hire a mini trencher or at least a handheld one.

I've heard mixed reviews about whether such a handheld trencher would go through solid chalk. Unfortunately the only access to the garden is through the house negotiating a reasonably tight bend, so a mini trencher / any type of heavy machinery isn't possible.

Your method with warning tape would be OK, but T&E down PVC conduit? not the easiest or nicest, I would tend to go for H07RNF flex down ducting.

H07RNF flex down ducting is probably a better option. I'll likely go with that. (Never heard of that flex before.)

If you’re going to dig down to 1 foot to lay in ducting, concrete and T&E, will that be cheaper than digging down 1 foot and laying in SWA?

Not at all. It's not a cost thing, I'm just not desperately happy about having SWA buried quite that shallow.
 
If you can get down to 200mm, get some twin walled ducting to run your swa in, cover it with plastic
Outside power - shallow depth {filename} | ElectriciansForums.net

still leave you with 140mm plus of top soil so the grass will grow. Just don't spike the grass in the summer. Better still, gets some artificial grass, so you won't have to.
 
Thanks all for the replies. Eventually just decided to lob the T&E over the neighbour's fence for the first half of the run, then bury it directly in the ground by an inch or so, so I can get to it easily again if needed by just pulling it up. I've attached a little paper note to one side of the fence explaining where it is so everyone else knows to avoid it in future.



;)


Just kidding. Used the twinwall duct & put SWA in (considered H07RNF, but eventually just thought sod it, I'll get the tough stuff.) Couldn't quite get down to 200mm for all of the run, so concreted that in place just to be sure, then laid tape. Took a while, but I'm happy enough with the end result.
 

Reply to Outside power - shallow depth in the Electrical Forum area at ElectriciansForums.net

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

YOUR Unread Posts

Electrical Forum

Welcome to the Electrical Forum at ElectriciansForums.net. The friendliest electrical forum online. General electrical questions and answers can be found in the electrical forum.
This website was designed, optimised and is hosted by Untold Media. Operating under the name Untold Media since 2001.
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock