garage lift installation questions
Discussion
I'm interested in installing a car storage lift in my garage. It's a single brick skin double garage built about 30 years ago. I'm starting to look into what's required to see if it's feasible. This is teh sort of lift I'm interested in - http://www.automotechservices.co.uk/products/as-4t...
The electrics will need upgrading. The garage is fed off of a fused spur on the downstairs ring and the lift will need at least a 16A feed so I either need to extend the ring into the garage or provide a dedicated feed in which case I might as well install a 32A feed.
I need to understand if the floor is strong enough to support the weight of two cars and the lift itself. I have no idea how thick the slab is and/or if there's any reinforcing steel within it. Any thoughts here?
And then there's the roof. It's constructed of trusses with about 8 ft clearance so I will need to contact either the truss manufacturer or a structural engineer about what truss mods are possible to give perhaps 10-12 feet of clearance in the centre of the roof area. Stripping the roof and installing new scissor or raised tie trusses would be a last resort.
Has anyone done similar?
The electrics will need upgrading. The garage is fed off of a fused spur on the downstairs ring and the lift will need at least a 16A feed so I either need to extend the ring into the garage or provide a dedicated feed in which case I might as well install a 32A feed.
I need to understand if the floor is strong enough to support the weight of two cars and the lift itself. I have no idea how thick the slab is and/or if there's any reinforcing steel within it. Any thoughts here?
And then there's the roof. It's constructed of trusses with about 8 ft clearance so I will need to contact either the truss manufacturer or a structural engineer about what truss mods are possible to give perhaps 10-12 feet of clearance in the centre of the roof area. Stripping the roof and installing new scissor or raised tie trusses would be a last resort.
Has anyone done similar?
Very much a "how long is a piece of string" type question. I suspect the floor will be fine (a car's weight spread across four significant sized pads on a four-post lift isn't much) but the roof could be another matter. You need to get a structural engineer to look at it and tell you whether the roof can be strengthened enough by bolting in extra wood to relocate the tie-beams to give you your headroom or if the roof will have to come off to install steel purlins (which might also necessitate building or enlarging supporting pillars along the side walls.
The roof of our extension sounds similar to what you hope to achieve and that needed steels (and fairly hefty ones at that). That was for a six-seven meter span (closer to six, I think) with the ceiling height about two feet above the wall plates.
Some pictures of the existing roof structure would help if you have them?
The roof of our extension sounds similar to what you hope to achieve and that needed steels (and fairly hefty ones at that). That was for a six-seven meter span (closer to six, I think) with the ceiling height about two feet above the wall plates.
Some pictures of the existing roof structure would help if you have them?
Edited by kambites on Sunday 25th February 19:39
Well all I can say for sure if that ours was built in 1990 (so similar age) with a similar design and was very definitely not strong enough for the modifications you describe without major work. 
Ours was spanning at least a meter more in both directions, though.
Ours was spanning at least a meter more in both directions, though. Edited by kambites on Sunday 25th February 21:38
My (pretty much identical by the look of it) lift ran happily from a std 13A socket.
You could drill into the slab to see how deep it is. I didn't bother and it was fine for 6.5yrs. I didn't bother when we moved either and that's been fine for another 6.5yrs. Probably always had less than 3 tonnes on it though in total, incl. lift weight.
Trussess....moved mine up the angle with bigger timber and better fixings. But only in the areas needed, so only about a third of them IIRC. Didn't have the same problem in the new place.
You could drill into the slab to see how deep it is. I didn't bother and it was fine for 6.5yrs. I didn't bother when we moved either and that's been fine for another 6.5yrs. Probably always had less than 3 tonnes on it though in total, incl. lift weight.
Trussess....moved mine up the angle with bigger timber and better fixings. But only in the areas needed, so only about a third of them IIRC. Didn't have the same problem in the new place.
This is exactly what I would like to do in my garage so I will be following this thread with interest. Finding someone to come out and look at the roof trusses and work out what is needed has been my biggest stumbling block so far, and also my first 
Long term project though so the plan was always to do one step at a time over 3-4 years.
Long term project though so the plan was always to do one step at a time over 3-4 years.
Murph7355 said:
My (pretty much identical by the look of it) lift ran happily from a std 13A socket.
I've got one of Automotech's two-posters, and that's officially 16A, but worked on 13A when I tested it. But given that it's a doddle to just run a spur from the ring (which'll be 32A "fused" at the box) and put a 16A commando socket on, why wouldn't you? If the consumer unit's in the garage, then it's a doddle to run a dedicated circuit.The main CU is at the far corner of the house from the garage which isn't ideal.
The fuse in the spur is rated at 13A - I don't think the regs allow a higher rating. And I do see some voltage drop in the garage; sometimes when I try to fire up my small air compressor in the garage in the winter it won't start so I carry it into the house and plug it into a socket in the hallway and it runs without issue.
The fuse in the spur is rated at 13A - I don't think the regs allow a higher rating. And I do see some voltage drop in the garage; sometimes when I try to fire up my small air compressor in the garage in the winter it won't start so I carry it into the house and plug it into a socket in the hallway and it runs without issue.
AW10 said:
The main CU is at the far corner of the house from the garage which isn't ideal.
The fuse in the spur is rated at 13A - I don't think the regs allow a higher rating. And I do see some voltage drop in the garage; sometimes when I try to fire up my small air compressor in the garage in the winter it won't start so I carry it into the house and plug it into a socket in the hallway and it runs without issue.
The whole garage is run on a 13A-fused spur? Basically, one of these...?The fuse in the spur is rated at 13A - I don't think the regs allow a higher rating. And I do see some voltage drop in the garage; sometimes when I try to fire up my small air compressor in the garage in the winter it won't start so I carry it into the house and plug it into a socket in the hallway and it runs without issue.
I think this might be a good opportunity to upgrade...
ha ha; don't quit your day job! 
No, something like this - https://www.screwfix.com/p/13a-switched-fused-conn...
An armoured cable perhaps 8m long then runs to the garage where there's a small garage consumer unit with two breakers - one for the lights and one for the sockets. Fairly standard stuff for a conventional domestic garage in suburbia.
No, something like this - https://www.screwfix.com/p/13a-switched-fused-conn...
An armoured cable perhaps 8m long then runs to the garage where there's a small garage consumer unit with two breakers - one for the lights and one for the sockets. Fairly standard stuff for a conventional domestic garage in suburbia.
What's the diameter of the cable running between the house and garage?
I'm pretty sure you're not allowed to spur more than a single socket off a ring these days so if you make any changes to the circuit you may be forced to run a new cable from the consumer unit. I'd probably want to do that anyway; the last place I'd want an iffy power supply is in my garage!
I'm pretty sure you're not allowed to spur more than a single socket off a ring these days so if you make any changes to the circuit you may be forced to run a new cable from the consumer unit. I'd probably want to do that anyway; the last place I'd want an iffy power supply is in my garage!
Edited by kambites on Monday 26th February 16:05
AW10 said:
No, something like this - https://www.screwfix.com/p/13a-switched-fused-conn...
Electrically, I'm not sure I see any difference.TooMany2cvs said:
AW10 said:
No, something like this - https://www.screwfix.com/p/13a-switched-fused-conn...
Electrically, I'm not sure I see any difference.Still, spurring the garage off the main ring is pretty horrible, however it's done.
TooMany2cvs said:
AW10 said:
No, something like this - https://www.screwfix.com/p/13a-switched-fused-conn...
Electrically, I'm not sure I see any difference.S6PNJ said:
I think what he is saying is his wire from house to garage feeds one of these: https://www.screwfix.com/p/british-general-5-modul... which then feed one of what he's linked to, so a big difference. He could run a 16A (or 13A) Spur off his CU to power the lift.
Not if it still connects to the rest of the house via a 13A fuse.[HOUSE] -> 13A fuse -> 8m of SWA -> garage CU -> garage wiring
Put a 16A breaker into the CU for the lift if you want, but the entire garage is still basically a very long extension lead plugged in somewhere in the house, and the spur switch's 13A fuse is going ping first...
TooMany2cvs said:
Not if it still connects to the rest of the house via a 13A fuse.
[HOUSE] -> 13A fuse -> 8m of SWA -> garage CU -> garage wiring
Put a 16A breaker into the CU for the lift if you want, but the entire garage is still basically a very long extension lead plugged in somewhere in the house, and the spur switch's 13A fuse is going ping first...
more likely to be:[HOUSE] -> 13A fuse -> 8m of SWA -> garage CU -> garage wiring
Put a 16A breaker into the CU for the lift if you want, but the entire garage is still basically a very long extension lead plugged in somewhere in the house, and the spur switch's 13A fuse is going ping first...
[HOUSE CU] -> 32A (or higher) MCB -> 8m of SWA -> garage CU -> garage wiring (13A spur)
I can't see the garage being wired off one of the ring mains, it is more likely to be fed from a separate cct on the main CU.
Edited by S6PNJ on Monday 26th February 16:25
TooMany2cvs said:
[downstairs ring main on 32A breaker] -> 13A fused spur -> 8m of SWA -> garage CU -> garage wiring
Put a 16A breaker into the CU for the lift if you want, but the entire garage is still basically a very long extension lead plugged in somewhere in the house, and the spur switch's 13A fuse is going ping first...
Edited slightly but generally accurate. Remember this garage started out as a domestic 2 car garage, not a workshop so the current electrics are fine for a few lights and the odd power tool, lawnmower or strimmer.Put a 16A breaker into the CU for the lift if you want, but the entire garage is still basically a very long extension lead plugged in somewhere in the house, and the spur switch's 13A fuse is going ping first...
And solving the electrics is the easiest bit. I haven't spoken to my tame sparkie yet but I reckon we could either run another identical cable into the garage and extend the ring into the garage or we could run a separate 32A feed from the CU on the far side of the house all the way to the garage.
The floor strength concerns me the most - how to figure out if it's up for the task.
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