Building an inspection pit
Discussion
Hi guys, i am going to be building an inspection pit in the garage and was wondering if anyone on here has done this.My main stumbling block is that the floor is about 6in thick an i am wondering how i am going to get through it as the still saws seem to only go to about 4in so i was thinking would it be better to buy a 9in grinder cut down as far as possible and then chisel down diagonaly then place the grinder down into the hole and cut further, has anyone tried this or got another way of doing it and also will it need bracing to stop the sides falling in with a car on top, thanks for any advice.
It would probably be easier(ish) to dig a whacking great big hole and do it properly, re-laying the floor afterwards.
Its a hell of a lot of work, but the consequences of having the pit come down around you arent worth thinking about, especially if the car above you finds its way in aswell
This is obviously a worst case scenario, but you get what I mean
Its a hell of a lot of work, but the consequences of having the pit come down around you arent worth thinking about, especially if the car above you finds its way in aswell
This is obviously a worst case scenario, but you get what I mean
Edited by The Nur on Sunday 5th April 17:08
Hi,
Quite right, check the legality thing first.
I had a pit built in my garage, here's how...
The floor was very thick but the builder bod hired a massive Stihl saw; it did the cutting easily.
I'd built a welded 2 x 2-in angle iron frame so the cut was marked to the outside of that.
Contruction: cement 'floor' 6-in thick, concrete block walls (NOT breezeblock.
Design: The iron frame sat on the top of the block walls and ends and was cemented in place. I got a wheeled pit jack/beam type, 2-tonne, reconditioned from a place in Hull. The jack rolled along the frame and locked up when weight was put on it.
The pit was a bit deeper than a kneeler pit and I used an old office/typist's chair with the backrest taken off to sit on and scoot along when working. I also added a little ladder (trhe type you fit to a Transit to get to the roof rack) and used 6 x 1 boards.
Problem: I asked the builder to first line the hole with visquine or a similar plastic as the area was wet (York). Silly sod told me - after the base had been poured - that he'd put TWO pieces of visquine in, with a generous overlap. This is why I needed an electric water pump and wellies to use my pit in wet weather. It made a great rat trap, though.
The aim was to create and inside-out 'parcel' of plastic to seal the hole. The overlap naturally leaked.
A small warning: The 2T pit jack was well worth the £200 or so it cost, plus going 100 miles to get it (it lifted a Rolls-Royce Shadow once. But remember that any flammable gas or vapour will collect in a pit and fry you if there's a spark. I fitted glazed bulkhead lights but was v careful of when I used them.
I've moved house so I've lost my pit now but if you do serious car work, as I did, a pit is invaluable.
By the way, I believe some outfits are still selling moulded pit liners - try 'Practical Classics' for a contact.
Good luck!
Quite right, check the legality thing first.
I had a pit built in my garage, here's how...
The floor was very thick but the builder bod hired a massive Stihl saw; it did the cutting easily.
I'd built a welded 2 x 2-in angle iron frame so the cut was marked to the outside of that.
Contruction: cement 'floor' 6-in thick, concrete block walls (NOT breezeblock.
Design: The iron frame sat on the top of the block walls and ends and was cemented in place. I got a wheeled pit jack/beam type, 2-tonne, reconditioned from a place in Hull. The jack rolled along the frame and locked up when weight was put on it.
The pit was a bit deeper than a kneeler pit and I used an old office/typist's chair with the backrest taken off to sit on and scoot along when working. I also added a little ladder (trhe type you fit to a Transit to get to the roof rack) and used 6 x 1 boards.
Problem: I asked the builder to first line the hole with visquine or a similar plastic as the area was wet (York). Silly sod told me - after the base had been poured - that he'd put TWO pieces of visquine in, with a generous overlap. This is why I needed an electric water pump and wellies to use my pit in wet weather. It made a great rat trap, though.
The aim was to create and inside-out 'parcel' of plastic to seal the hole. The overlap naturally leaked.
A small warning: The 2T pit jack was well worth the £200 or so it cost, plus going 100 miles to get it (it lifted a Rolls-Royce Shadow once. But remember that any flammable gas or vapour will collect in a pit and fry you if there's a spark. I fitted glazed bulkhead lights but was v careful of when I used them.
I've moved house so I've lost my pit now but if you do serious car work, as I did, a pit is invaluable.
By the way, I believe some outfits are still selling moulded pit liners - try 'Practical Classics' for a contact.
Good luck!
Edited by davhill on Sunday 5th April 17:11
Edited by davhill on Sunday 5th April 17:15
theaxe said:
Have you considered a basic lift? This one will get a car a couple of feet up and because there's no scissor underneath you get good access for a crawler.
I would NOT like to be under my car with that holding it up. It may claim to be safe, but it doesn't look it. A lot of stress on angled joints, if one joint fails!!!!..... I'd want something failsafe (so if something breaks, the car stays up).I have one in my garage and have used it twice in 30 years of living here. It's too short - you have to pull the car over you when you're down there or you're only under the bumper, and it's not deep enough. Work out the sizes very carefully or it'll be an expensive white elephant. Just my two pennyworth...
I've got one in my garage. It's about 12ft long and 6 ft deep. Been using it a lot recently as I've had a few winter projects to keep me busy. There's an extractor fan in there to remove any fumes and a sump hole to collect any spills etc so I can empty it out later.
Much better than working under a car using axle stands.
Much better than working under a car using axle stands.
To get through 6 inches of concrete, hire the biggest breaker (like a pneumatic drill, but electric) they have.
Don't believe the spec that says the one like a big Black and Decker will go through 9". You want the biggest you can get!
Apart from the fumes/flooding problems you also need to take account of making sure the sides don't fall in when you dig it (ie before you've lined it) - if you are on chalk as we are that isn't a problem, except you'll need the breaker do dig it out; if you're on Essex sand could be like digging a hole on the beach - once you're 3 feet down you can't get any deeper cos it's falling in quicker than you can dig!
I did see some nifty boxes yesterday at a restorer, he had a rectangular box for each wheel about 6" x 12" and 12" high with the top curved to the tyre diameter and a bigger base to give stability. You can make them the right height to suit your trolley jack. Cheaper than the suggested ramp and easier to make than a pit!
Don't believe the spec that says the one like a big Black and Decker will go through 9". You want the biggest you can get!
Apart from the fumes/flooding problems you also need to take account of making sure the sides don't fall in when you dig it (ie before you've lined it) - if you are on chalk as we are that isn't a problem, except you'll need the breaker do dig it out; if you're on Essex sand could be like digging a hole on the beach - once you're 3 feet down you can't get any deeper cos it's falling in quicker than you can dig!
I did see some nifty boxes yesterday at a restorer, he had a rectangular box for each wheel about 6" x 12" and 12" high with the top curved to the tyre diameter and a bigger base to give stability. You can make them the right height to suit your trolley jack. Cheaper than the suggested ramp and easier to make than a pit!
speed8 said:
Much better than working under a car using axle stands.
Better how?At least with the car on stands you can move all round under the car on a crawler and position yourself wherever you want for best visibility/access. In a pit surely you can only position yourself on a relatively narrow line down the car and are working overhead all the time.
I always fancied one of these;
http://mech-mate.co.uk
These new lift systems seem quite good, if a bit expensive.
http://mech-mate.co.uk
These new lift systems seem quite good, if a bit expensive.
bigdavy said:
I always fancied one of these;
http://mech-mate.co.uk
These new lift systems seem quite good, if a bit expensive.
Problem is the site shows no prices, or much of anything but i have a feeling that they would be very expensive.http://mech-mate.co.uk
These new lift systems seem quite good, if a bit expensive.
Dracoro said:
theaxe said:
Have you considered a basic lift? This one will get a car a couple of feet up and because there's no scissor underneath you get good access for a crawler.
I would NOT like to be under my car with that holding it up. It may claim to be safe, but it doesn't look it. A lot of stress on angled joints, if one joint fails!!!!..... I'd want something failsafe (so if something breaks, the car stays up).stewartcampbell said:
bigdavy said:
I always fancied one of these;
http://mech-mate.co.uk
These new lift systems seem quite good, if a bit expensive.
Problem is the site shows no prices, or much of anything but i have a feeling that they would be very expensive.http://mech-mate.co.uk
These new lift systems seem quite good, if a bit expensive.
Do your sums on this, as with builders, tool hire, digging, concrete etc. it sounds like you're getting pretty close to;
http://cgi.ebay.co.uk/Vehicle-Lift-2-post-240v-400...
Which would be a whole lot easier (and safer).
http://cgi.ebay.co.uk/Vehicle-Lift-2-post-240v-400...
Which would be a whole lot easier (and safer).
maser_spyder said:
Do your sums on this, as with builders, tool hire, digging, concrete etc. it sounds like you're getting pretty close to;
http://cgi.ebay.co.uk/Vehicle-Lift-2-post-240v-400...
Which would be a whole lot easier (and safer).
Two reasons that im not getting a lift, the garage is not high enough and the costs wont be that bad as i have bought a still saw for £40 and will sell it on afterwards and i know a builder.Would also not be able to get a lift to where i live as its the far north of scotland and would be to far to collect one as most for sale are in england and even the ones in scotland would be a long trip and i have no van.I think actualy thats more than two reasons.http://cgi.ebay.co.uk/Vehicle-Lift-2-post-240v-400...
Which would be a whole lot easier (and safer).
stewartcampbell said:
Would also not be able to get a lift to where i live as its the far north of scotland and would be to far to collect one
Ah, the joys of living in Caithness. I remember building a kit car when we lived in Wick. The miles I put in to collect various bits was unbelievable. Could have bought a bloody good car for the same money spent on the kit ! Was an enjoyable way to spend a year though - wifey doesn't see it the same way for some reason, and it was a great place to live (back in the eighties anyway)
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