Converting a shed to an office

GordonT · Oct 29, 2013

Hello all,

Good to meet you.

So I am currently about to embark on a project. I currently work from home about once per week (computer related) and this could increase soon. I currently work from my lounge that is getting less practical with my two daughters running about.

I have a garden shed that is about 5 meters (at a guess) from the house that I am planning on converting into an office. Suffice to say I have a number of insulation etc type problems and the fact that I want a window (currently its a dodgy plastic panel that you can't see through) etc but first things first I would like to get the electricals in place before I put up the drywall.

I am trying to do this as cheaply as possible without sacrificing quality or safety so would like to do most of the work myself.

Basically I am talking about probably 4 power sockets on the back wall and one each on either side with a light and a switch. Most of the power would be computer, monitors, printer but also maybe a kettle so I don't have to leave for a tea and if I get the insulation wrong maybe a small heater in the winter.

So I was thinking of installing the sockets on a ring and then also digging a trench and laying conduit to feed the cables through to the house (two conduits in fact with one carrying network cable and maybe phone extension).

I wanted to get to that stage and then get an electrician out to connect it from there to the houses fuse box. That way the boring stuff (from an electricians point of view) and the majority of the drilling / digging should be done leaving them the interesting / complicated part.

The main questions I have are around if anyone sees any problems / gotcha's with this. I was planning on going to B&Q to get everything basically and was hoping they have a product called outdoor wire to go through their product called outdoor conduit.

I haven't done it yet but I am planning on googling how deep the trench needs to be and if there is a special type of B&Q outdoor wire I would need.

Other than just general comments / advice the other question I had was whether I would be better doing that and basically passing the light cable and the two ring cables through the conduit or whether I would be better off installing a consumer unit in the shed to terminate them all on and then just one cable back through the conduit.

Any thoughts / comments / advice would be greatly appreciated please.

Thanks very much

HandySparks · Oct 29, 2013

Welcome to the forum.

I recommend that you talk to one or two local electricians before you start. If you say where you are, someone on here may be local to you.

Having said that, if you were asking me to do the job, I would ask you to lay a couple of lengths of 50mm bore flexible underground ducting. You should be able to buy this from your local builder's merchant or online. Get black for electricity cables. Lay them about 500mm deep, spaced apart by a few inches. When backfilling, either use sharp sand or pea shingle for the first few inches or make sure that you've removed any big stones, pieces of brick, etc from the soil. You need to lay a length of marker tape in the trench at least 150mm above the duct. If the duct runs under a veg plot or similar, you may choose to lay it a bit deeper.

I would run an armoured cable through the duct from the CU to the shed and install a small CU in the shed with RCD protection to the final circuits. The detail will vary with your existing earthing system. Let your electrician select the cable and other bits and pieces. He might not want to install something that you've bought incorrectly and he may have stock of some items, eg marker tape and possibly ducting, which will save you some money.

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Ridgicoil | Polypipe Civils
63MM X 50M RIDGICOIL FLEXIBLE CABLE DUCTING BLACK NEW | eBay
Electric Cable Below Tape 150mm x 365Mts

Octopus · Oct 29, 2013

If I were you I'd be digging the trench and working with a spark to ensure that what you do meets with the current regulations.

Are you sure you need network cable to the shed, you may well find using Powerline products such as those made my Devolo might make things easier for you.

Maybe you should post your location and get a couple of sparks round......and as for B&Q outdoor cable, what is this?

SirKit Breaker · Oct 29, 2013

I'm with the others on this one.

You are taking on a sizeable job, with a lot to consider. Nothing that you want to do is complicated, but it has to be right, you are into building regs territory, and that has legal implications.

By all means get the materials and do the job, but work with a local spark to get you off on the right foot, and to dot the I's and cross the T's.

Post up your area, you will be inundated with offers to help and advise.

Cheers………..Howard

GordonT · Oct 29, 2013

Thanks very much for the responses.

I am in Witham in Essex.

I did consider powerline. In fact right now I have the router in the bedroom and I run powerline to my PC in the lounge so it would just be an extension of that.

It has been working well but I am a networking guy at heart so always think a nice cat6 run would be better. Have actually been contemplating wiring the house with cat6 but given the drywall is already in place there it isn't such a tempting idea.

Andy78 · Oct 29, 2013

If you are set on network cable, you can get a grade of exterior cat5/6 with a tougher outer. This would be best if you are considering pulling it through a duct.

I recently installed some powerline adapters for a customer who wanted the internet in an out building. Over 60m of power cable away from the router, through 2 consumer units, and I was getting near identical speeds as hard wired in to the router with a patch cable. Worth considering.

Regards the electrical install, as mentioned, get a couple of local electricians to give you prices. You will be able to gauge their willingness to have you involved in the install, and to what level. They will also be able to give you a better idea of a shopping list if you insist on buying materials yourself. Try not to skimp on the materials too much, there is cheap gear, then there is cheap gear. The difference between tat and discounted decent gear is not always a lot either.

GordonT · Nov 1, 2013

Powerline is good but I think it tops out at 200Mbps where as GigE over Ethernet can get me faster. Of course that is just within the home as I would be limited by the broadband speed to less than both of those.

Think what I may do is just add a second ducting with nothing in it but a string pull through. That way if I feel the need to add something in the future I don't have to re-dig the trench.

I have been thinking about the idea of doing part of it myself. I think what is probably best is to get some quotes for the various elements. The sockets etc might be cheaper through the sparky if they can get them at trade prices and given the toughest part is probably the house bit the additional cost of having them wire the shed might be small enough just to get them to do it. So in effect I would be a trench digger

Speaking of which what would you say was the best way to find a good local electrician?

I am currently looking at the following:

trustatrader.com
ratedpeople.com
mybuilder.com

Thanks

Spoon · Nov 1, 2013

Where about in the UK are you? There will be loads on this site that should be able to help.

GordonT · Nov 1, 2013

I am in Witham in Essex. It is between Chelmsford and Colchester.

Spoon · Nov 1, 2013

Hopefully some of the people here will contact you. Get about 3 quotes and take it from there.

I would go with a second ducting. Put your ethernet cable in with lots of spare and just done connect it, until you decide if you want it. I would hard wire but thats just me. While you are at it, put an alarm cable and phone cable into the second ducting. Also a pull string for anything else in the future.