Jump to content

Garage inspection pit


Paddy
 Share

Recommended Posts

I'm going to have an old garage renovated and re-roofed which will give me the opportunity to get a small digger in to dig an inspection pit. I’m only after something modest to help with oil changes, greasing etc. anyone any ideas on size and depth, OK I do realise to keep the width less than the axel width :lol: but what’s a practical length and depth to work in. Any other things I should consider?

regards

Link to comment
Share on other sites

dig hole then cover bottom with sand lay blue viscuen polythene on bottom 7 up the sides like forming a pond. then lay 6-9inch concrete with fall to 1 end so you are not stood in water even put little well in so u can scoop water out. then build your walls up in 9in hollow blocks.bring poly up sides get some comprashion bords like felt ?. put between poly and your infill then fill blocks with wet concrete to the top then concrete floor. if over 8ft long build in a piller to stop walls from falling in and crushing you. hope this helps its a job n a half to keep water out.

swanny

Link to comment
Share on other sites

My in-laws have recently moved into a house with a pit in the garage, and have been happy to let me use it :D

A couple of important bits... At least as long as the vehicle, with a way to get out of the pit when the vehicle is on top - in our case, there is a bit on the side with scaffolding pipe let into the sides to climb up. This means that it only just has to be as long as the vehicle.

Think carefully about how you are going to cover it when it isn't in use. In our case, it has 5 inch thick, 20 inch wide bits of timber across it, in a groove at the side so that it is flush with the ground. That means that if you want to jack up part of the vehicle, you just leave a couple of them in place, and jack from there.

This pit was dug for the previous owners old VW beetle, so it is a little too deep for a 90 with big tyres and a lift. I would suggest that you want your eyes to be level with the interesting bits on the landy - perhaps about level with the axle.

A couple of extras - some power points down there are incredibly useful - particularly if they are at the rim of the pit - just make sure that they are powered from a protected (rcd) source, for when the garage floods, and the pit fills with water (they live near Tewkesbury)

On the same note - if the bottom of the pit slopes VERY gently to one end, it makes emptying it a lot easier.

Width - as wide as you can go without the vehicle falling in.

Link to comment
Share on other sites

I definitely think you need the pit to be 'T' shaped, for taking a false floor and jacking, as mentioned above.

I reckon it's better to be too deep than too shallow, you can always have something to stand on to lift you up a bit, going lower would be a lot harder once you've laid a floor.

Link to comment
Share on other sites

You need to know the water table for your site. It'll soon show up when you dig it. If the water table is above the floor of your pit it'll always try to fill with water.

A mate had this problem. Tanked the pit with visqueen as stated previously, then 9" blocks etc. Clever part was a sloping floor with an old plastic water tank buried at the deep end with a grating on top. He then fitted a submersible pump in the tank to empty out any water. He piped this straight to the drain...not recommended as it probably had all sorts of pollution in it.

He also made a 6" deep channel at the wall tops with 6' fluorescent tubes behind perspex covers so he didn't need to use lead lamps.

All electrics were via an isolating transformer and rcds, he was a sparky so knew what he was doing. Electrics and damp pits don't mix!

Link to comment
Share on other sites

Both this house and my last had inspection pits, very usefull and saves the back, most points covered already but i would certainly recommend drainage if needed, concrete sides, use replaceable concrete slabs as a base with a kind of ditch underneath.

Current one is 18 feet in length, concrete with spencer steel reinforcement, white wash sides, ladder access both ends, concreate slabs with a drainage ditch running whole lenght underneath, this so possible to power wash from inside, portable light fitting, 1 metre wide.

Over the years had problems with the boards, used to use railway sleepers but they are heavy, now use 18mm ply with strenghtling beams underneath.

Oil spils are the worse hence the replaceable slabs the floor does get very dirty with time, also keep a supply of sand to mop up spils quickly, the smell can be overpowering.

Don't go down with engines running, watch out for fuel leaks

If you do make it get a digger and a big skip plus plenty of shoreing wood to support the sides

Link to comment
Share on other sites

Probably not relevant in your case, but maybe in others.

If wanting to fit pit in a new garage, make sure the foundations of the building are modified to suit having a pit nearby. If not, you will not get the construction signed off by a building inspector and will be in a spot of bother...

My over-enthusiastic mate dug his pit out in his new house then asked the architect what he thought (over the phone). Arcitect said no, garage foundations are not suitable to have a pit inside and it would invalidate design :o . Mate then promptly filled it back in again before arcitects next visit :rolleyes:

Link to comment
Share on other sites

Partly alluded to above - you need to think about how to clear noxious vapour from the pit as most hydrocarbon vapours are heavier than air and will gather in the bottom. Not good for breathing or if you are using power tools !

Water drain pump would do it (its how yotties clear the bilges of such things), but you would need one that was capable of running dry for up to a couple of minutes.

Link to comment
Share on other sites

If there is room you could make the pit in a T shape with a lift out section to drive over the leg of the tee.Having spent many years earning a living using a pit,I was always frustrated at not being able to be able to get good access to the side of vehicles.(Eas kit on classic RR's,sill repairs etc)

A four post lift is so much nicer !

Link to comment
Share on other sites

Thanks for all the replies lads, other than the work involved there seems no reason why I should not go ahead and it will save a lot of laying on my back back trying to work. A lot of good construction and safety points raised which will be heeded.

regards

Link to comment
Share on other sites

  • 14 years later...

I've got a single garage that's not attached to my house. It's got a concrete base and a rather deep inspection pit.

Inspection pit is brick built and pretty deep.

I want to fill it. Is there anything I need to fill it with? Also, what about a DPM?

It's got about a foot of water in at the moment, probably the water table seeping in.

I've got an old concrete shed base I'm going to Kango up so that could go in there but probably the pieces would be too large.

Link to comment
Share on other sites

If you’re won’t/can’t use it then drying it out first and then backfilling. You’ll probably need a wacker plate to get it compacted as you go and minimise it sinking over time. Are you planning on concreting the top? In which can you can tie the new concrete to the old. 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy