Hi Has anyone fitted an inspection pit in their garage.
I am thinking of using a pre formed fibreglass lining. I've searched tinternet but only found one site called Mech Mate, just waiting for them to
get in touch.
Any recomendations ?
I have the fume, access & power ideas sorted but is there anything else you can think of?
Cheers
RD 
pits are dangerous i would go for a lift every time given the space.
Either drainage in the bottom or pump to take fluid out.
I built one in my garage at my old house. I went to a lot of trouble to line it with polythene and bricks. However as it was below the water table it always filled with water. I installed a sump pump which worked well. I think you have to be carefull to consider the effect of ground pressure on the lining, as the weight of your house will try to force the ground outwards. Just something to bear in mind.
Lifts are dangerous too, as are cars and life in general but certain situations result in limited solutions.
The two arguments I've heard said against pits are:
1. People falling in when the covers are off.
2. Heavier-than-air fumes gathering in the pit and suffocating the person working in there.
I stress that this is what I've heard people say - I have no personal experience. However, it is worth noting that hardly any modern garages
have pits, despite them being far cheaper than lifts.
If the fume idea is sorted then there's just the issue of not falling in to contend with.
Anyway, the OP wasn't asking for health and safety advice.
Had one fitted in our new garage. I wasnt convinced it would be that useful, but I've changed my mind about it. It's helped with almost every job i've done since it's been installed!
personally having been down in a pit with so called drainage/ventilation that caught fire i can 100% say they are bloody dangerous. my friend an i were lucky as there was a fire extinguisher handy. what was most shocking is that the flames were hardly visible.
Will find out what it is for you.
The most practical alternative I saw was in the back of a domestic garage... you have to picture this garage - built on quite a steep slope to the rear... you open the front doors, to see another set of doors in the back wall. Open those doors, and find a pair of what are basically very thick walls going further back. When this bloke wanted to work under his car he just opened the back doors and rolled his car out! Note that he did have stops on the end of the walls to prevent him from driving right off...
Forget all this crap about pits being dangerous. A pit which is well designed and built is a great addition to any workshop. There is one in my
parents garage , my brother has one in his and there was one in my parents last house and nobody has died from owning one. Just use common sence
something which is lacking in todays society when using it.
Lifts can be just as dangerous again if common sense is not used.
You dont need a fibreglass liner for a pit, the ones in our family have been built just by digging the hole, lay some visqueen dpc then shutter off
and back fill with concrete. repeat until you reach the top.
You can use ladders to get in and out but its far safer to build/cast steps into the pit aswell. Also dig a soak away at one end.
None of our pits get damp or have fallen in!
Pits are used in modern bus garages.
I don't believe the Health and Safety nannies were part of the initial question. Just use common sense in useage of it!
I had pit installed in the garage of my previous house. There are some mathematics involved as to angles with the garage walls from the base of the
pit (to avoid wall failure, comply with building regs. (if you have/need/want to) and other nasties, these are on the web, or you can simply utilise
the services of a surveyor (not too expensive).
The builder simply came in, cut the hole, lined it with polythene and block, leaving apertures for me to install the lights. A half brick width at the
top for the planking. Fantastic job. I have some pictures if you'd like a look, but no idea how to post them here.
Made work on the (any) car just so easy, especially welding, servicing.
quote:
Originally posted by David Jenkins
2. Heavier-than-air fumes gathering in the pit and suffocating the person working in there..
quote:
Originally posted by rusty nuts
quote:
Originally posted by David Jenkins
2. Heavier-than-air fumes gathering in the pit and suffocating the person working in there..
Very nearly happened to me about 30 years ago , Only had a bit of petrol in the bottom of the pit due to a leaking fuel system on a car that had been over the pit, got in the pit to mop it up and woke up in A and E.
We have fabricated many pit liners for commercial use, including vosa approved centres.
They are the same idea as you are looking at with the fibreglass liner, except ours are fabricated from 4mm steel.
The pit is fabricated, and braced up on the inside. it is then dropped into the hole on site, and then back filled with concrete around the outside of
the pit. Once the concrete has set then the braces are removed. The last one i fabricated was 23m long for use inspecting lorries
I've been working using a pit for near 20 years & hav'nt had any problems with fumes though I dont doubt the potential for a problem
& as others have said just do a bit research (sounds like you've done that) you will have no problem at all.
The pit I use (& made!) was fabricated as a steel tank & lowered into the hole, chains welded to the outside so the concrete could get a good
hold of the walls. We should have made the floor stronger though, did'nt think the water pressure would bend it but it did, bowed it up like the
top of a submarine! We welded a pipe fitting to the floor & drilled the floor through the middle of it & the resultant fountain came up
almost 5' ! We pushed it back down with a JCB, braced it with 25mm box steel & fitted a false floor over it, been right since.
Thinking about it being a sealed tank will stop any fumes/bad air coming from the ground & you'd only have to worry about fumes from things
like fuel or welding gas. Sometimes there is a bad smell but that means you've a dead mouse!
[Edited on 27/7/11 by hillbillyracer]