Advice on Wiring my Garage

[special_dx]

Hi All

I'm a newbie to wiring and this forum, but I am reasonably technically minded and cautious. I will try to keep this simple, but I am behind the curve on requirements and terminology and I would like advice on what I need to do regarding regulations and my expectations of what I can actually instal.

My plan is to assemble the materials I need to wire my garage and get a local part P electrician to do the job with my help as labour as I am on a tight budget; he has already agreed and given me some basic advice, but I wanted some collective knowledge and guidance on my ideas.

The structure:-

-New concrete sectional 18'3" by 8'6" Lidget pent roof garage with steel doors next to boundary.

-I have insulated the ceiling to stop condensation using 30mm polystyrene with 1/4" ply and treated lath frame and painted the floor with a polyurethane product.

-Doors well sealed against moisture ingress and wall sections sealed with mastik at the slab.

-I have put some freestanding kitchen units and work top in half of garage as work area for mechanical fitting and power tools (domestic/hobby use only), the other half houses my motorbikes.

Advice needed:-

-The consumer unit in the house is full, it was installed less than 18 months old as part of a full rewire when we bought the property; can I get a second smaller CU installed to feed the garage via 10-15 feet of suitable SWA cable and what will it need in terms of switches/breakers etc?

- I have been given two brand new CUs, one is an empty GE 6-way metal unit to IP41 (100A main switch fitted), the other is a Protek IP65 Plastic 100A 4-way unit with a main switch and 40A RCBO pre-installed. I also have a small selection of new and used MCBs of 6A and 32A type B that I was given at the same time. Is any of the equipment I have suitable to use if one is installed in the house and the other in the garage and can the IP41 unit be used in a garage as it is larger?

-My mains supply comes into the house from an underground cable of 1960s vintage, do I need to be aware of any possible issues to check.

-Should I consider seperating earth for the garage from that in the house.

- I would like to instal one twin tube 8' flourescent (switched at two doors), 1 or 2 150W security lights, 3 double metalclad sockets, a single metalclad socket, a 13 amp fused spur for a small lathe and a suitable spur for a welder (30A?). Is this reasonably acheivable or should I aim for a lesser setup?

Any assistance will be very gratefully received, but it needs to be in plain language or include some links to help me decifer the terms used.

Thanks
Matt in South Cheshire

 

[Adam W]

You may be able to take a submain directly from the supply, depending on how the cable is to be installed - obviously I can't tell you that without seeing the setup.

Regarding the kit you've got and what to get it's best to talk that over with your electrician as he's the one who will be signing it off - essentially putting his name on the job. I could give you links for cheap(ish) kit to get but he might get a bit annoyed at being presented with a load of kit which he doesn't like and you've gone out and bought because someone off the internet down the other end of the country has told you to get it without even seeing the job.

A lot of (if not most) supply heads were installed a long time ago. Often they will be the most mangled, dirty, unappealing parts of an installation, but the supply company won't change them if they work alright or unless you are up for a fleecing.

You might be able to export the earth from the house, depending on the supply type and whether or not you need to bond services, structural steelwork etc - that issue always provokes strong debate around here!

You might be able to use all that lot, it depends on what else is likely to be used at the same time. Obviously you would calculate the size of the supply cable after taking into consideration the maximum amount of power to be used in the garage at one time - if it's just you going to be working in there you probably wouldn't use the welder at the same time as the lathe, similarly if you're doing a bit of welding while your missus is cooking the dinner on an electric cooker while your other missus is having a shower (electric) all at the same time you might end up blowing the supply fuse - I don't know your personal circumstances and probably shouldn't speculate.

 

[GOODWIN]

Hi All

I'm a newbie to wiring and this forum, but I am reasonably technically minded and cautious. I will try to keep this simple, but I am behind the curve on requirements and terminology and I would like advice on what I need to do regarding regulations and my expectations of what I can actually instal.

My plan is to assemble the materials I need to wire my garage and get a local part P electrician to do the job with my help as labour as I am on a tight budget; he has already agreed and given me some basic advice, but I wanted some collective knowledge and guidance on my ideas.

The structure:-

-New concrete sectional 18'3" by 8'6" Lidget pent roof garage with steel doors next to boundary.

-I have insulated the ceiling to stop condensation using 30mm polystyrene with 1/4" ply and treated lath frame and painted the floor with a polyurethane product.

-Doors well sealed against moisture ingress and wall sections sealed with mastik at the slab.

-I have put some freestanding kitchen units and work top in half of garage as work area for mechanical fitting and power tools (domestic/hobby use only), the other half houses my motorbikes.

Advice needed:-

-The consumer unit in the house is full, it was installed less than 18 months old as part of a full rewire when we bought the property; can I get a second smaller CU installed to feed the garage via 10-15 feet of suitable SWA cable and what will it need in terms of switches/breakers etc?

- I have been given two brand new CUs, one is an empty GE 6-way metal unit to IP41 (100A main switch fitted), the other is a Protek IP65 Plastic 100A 4-way unit with a main switch and 40A RCBO pre-installed. I also have a small selection of new and used MCBs of 6A and 32A type B that I was given at the same time. Is any of the equipment I have suitable to use if one is installed in the house and the other in the garage and can the IP41 unit be used in a garage as it is larger?

-My mains supply comes into the house from an underground cable of 1960s vintage, do I need to be aware of any possible issues to check.

-Should I consider seperating earth for the garage from that in the house.

- I would like to instal one twin tube 8' flourescent (switched at two doors), 1 or 2 150W security lights, 3 double metalclad sockets, a single metalclad socket, a 13 amp fused spur for a small lathe and a suitable spur for a welder (30A?). Is this reasonably acheivable or should I aim for a lesser setup?

Any assistance will be very gratefully received, but it needs to be in plain language or include some links to help me decifer the terms used.

Thanks
Matt in South Cheshire

is there any ways on ur CU u could double up like a bell cct to a light one,

 

[GOODWIN]

Hi All

I'm a newbie to wiring and this forum, but I am reasonably technically minded and cautious. I will try to keep this simple, but I am behind the curve on requirements and terminology and I would like advice on what I need to do regarding regulations and my expectations of what I can actually instal.

My plan is to assemble the materials I need to wire my garage and get a local part P electrician to do the job with my help as labour as I am on a tight budget; he has already agreed and given me some basic advice, but I wanted some collective knowledge and guidance on my ideas.

The structure:-

-New concrete sectional 18'3" by 8'6" Lidget pent roof garage with steel doors next to boundary.

-I have insulated the ceiling to stop condensation using 30mm polystyrene with 1/4" ply and treated lath frame and painted the floor with a polyurethane product.

-Doors well sealed against moisture ingress and wall sections sealed with mastik at the slab.

-I have put some freestanding kitchen units and work top in half of garage as work area for mechanical fitting and power tools (domestic/hobby use only), the other half houses my motorbikes.

Advice needed:-

-The consumer unit in the house is full, it was installed less than 18 months old as part of a full rewire when we bought the property; can I get a second smaller CU installed to feed the garage via 10-15 feet of suitable SWA cable and what will it need in terms of switches/breakers etc?

- I have been given two brand new CUs, one is an empty GE 6-way metal unit to IP41 (100A main switch fitted), the other is a Protek IP65 Plastic 100A 4-way unit with a main switch and 40A RCBO pre-installed. I also have a small selection of new and used MCBs of 6A and 32A type B that I was given at the same time. Is any of the equipment I have suitable to use if one is installed in the house and the other in the garage and can the IP41 unit be used in a garage as it is larger?

-My mains supply comes into the house from an underground cable of 1960s vintage, do I need to be aware of any possible issues to check.

-Should I consider seperating earth for the garage from that in the house.

- I would like to instal one twin tube 8' flourescent (switched at two doors), 1 or 2 150W security lights, 3 double metalclad sockets, a single metalclad socket, a 13 amp fused spur for a small lathe and a suitable spur for a welder (30A?). Is this reasonably acheivable or should I aim for a lesser setup?

Any assistance will be very gratefully received, but it needs to be in plain language or include some links to help me decifer the terms used.

Thanks
Matt in South Cheshire

http://www.napitonline.com/downloads...utbuilding.pdf

 

[special_dx]

Thanks to you all for your advice.

My sparky is pretty down-to-earth, as long as it can be fitted in a safe compliant way he said he doesn't mind what I get, last time I saw him he thought he would have to split the tails and use a Henley block to fit a second CU.

The only non RCD circuit is for the smoke alarm, this is on a 6A MCB all the rest are 32, 16, or 6A MCBs off the two RCDs. I need a 30A connection for the welder in the garage in addition to 6 normal sockets and a strip light.

 

[BlueToBits]

Have you considered warranty? In supplying materials yourself you are effectivley taking on the warranty obligation in that you have to take any faulty items back possibly paying for their removal and re-fitting. This could become very expensive. If your electrician supplies them, the obligation is with him. He is also more likely to work with greater care to prevent any problems occuring in the future. He can't blame the materials if he supplied them.

 

[Deleted member 9648]

Somewhat irrelevant to your question but if you had the house rewired just 18 months ago it was pretty short sighted of them to install a CU with no spare ways.

 

[special_dx]

Tell me about it, they even knew I was intending to get a garage erected and wired. There was a rethink after the materials including the CU were delivered - it was down to poor communication between the guy who did the quote and the sparky, no excuse as it was their cockup. The sparky is now on the council streetlighting as his employer was a prat who did not pay on time, so he is doing my job as a foreigner while he still has part P.

 

[special_dx]

Just to add to the picture, the underground supply has a large bare earth wire (thick multicore) coming from it to the meter and the earth block.

I am assuming I will end up with a small consumer unit with a suitable main switch and MCB feeding the SWA, the SWA will be earthed at both ends and connected to a second CU with an RCD and MCBs in the garage.

I estimate that the SWA will need to be 20 feet or less. If I have 3X 2-gang sokets, 2X 150W security lights, a 6' twin flourescent tube, a 13A spur and a 30A spur can I use 10mm SWA or will it need to be bigger and what RCD/MCBs do I need? As I said at the start I already have some free kit from a mate and a lot of it matches, so I would like to work out if I can use it.