Bradbury 4 post lift needs to be secured in thebottom?

[henk]

I can buy a recently maintained Bradbury 42/43 that can lift 4000kg but I rent the space I use and am not allowed to drill holes in the floor.

Any other way to install it that I can work safe?

[Snagger]

Would stud plates epoxied to the floor work?  Failing that, a box made of rigid steel extrusion with stud plates welded into the corners should give sufficient location for the posts.

[Stellaghost]

You will need to look at available space around where you plan on putting it, if your not allowed to fix it down properly then you will need to build a load spreading framework that lies on the ground and then the lift can be bolted to it. I would suggest H section or channel , obviously your lift will sit higher so you need to take that into consideration, will be ok with a 4x4 but lower cars might be an issue regards Stephen

[David Sparkes]

If you are not allowed to drill holes in the floor I do not see how installing a subframe will help, in terms of overall stability.
I can see that a sub frame, with suitable corner bracing, will keep each leg positioned correctly in relation to each other leg, but overall the stability of the lift will still be severely compromised, unless you are allowed to secure the subframe to the walls.

I would be concerned about lift stability with a 2 or 3 ton car 6ft from the ground, and no external stabilising connections.

Regards.

[Snagger]

3 hours ago, David Sparkes said:

If you are not allowed to drill holes in the floor I do not see how installing a subframe will help, in terms of overall stability.
I can see that a sub frame, with suitable corner bracing, will keep each leg positioned correctly in relation to each other leg, but overall the stability of the lift will still be severely compromised, unless you are allowed to secure the subframe to the walls.

I would be concerned about lift stability with a 2 or 3 ton car 6ft from the ground, and no external stabilising connections.

Regards.

The centre of gravity will never approach the edges of the “box” created by a steel base perimeter, so I can’t see any stability problem.  Even a two-post lift would be stable if it had very rigid ground beams to bolt to.

[steve b]

There is also the issue of setting the legs dead vertical for correct operation. 

I would question how secure/stable it would be without a structural steel type base as Stellaghost said above. 

Imagine you are underneath a 1.5-2T vehicle heaving on a stuck bolt with a big knuckle bar with all you've got...

It could work with tie flat bars between the feet in all 4 places along with diagonal ties one end and one side between the legs?  

Or plead with the landlord

Steve

[Retroanaconda]

No way I would go under a lift that wasn’t bolted down, I don’t really see any way to avoid some kind of fixing to the floor. 

[elbekko]

What's a floor other than a sturdy frame under the lift? If you have a large enough frame that extends far enough, I don't see why it wouldn't be stable.

It'll also be stupidly expensive and in the way, so can't you just drill some holes and fill them up when you move out?

[Troll Hunter]

Even if you are allowed to drill holes you need to be sure that the floor is strong enough.  Unless it has steel re-bars and is probably at least 4" thick it probably isn't.

Mike

[Bowie69]

There are lifts available that don't bolt down at all, in fact you can fit wheels on and push it about.... doubtless they are designed differently to a standard lift.

[smallfry]

What about tie beams at the TOP of the posts, forming a square, not diagonally, hopefully obviously. Bolt them if possible.

Then just weld some bar between the four bases.

 

Another good solution would be to sell it to me for 100 Euros, delivered 😁 Save all that bother.

[Troll Hunter]

Even less bother to sell it to me for CAD100, including delivery!  Save all that worry about concrete and welding, etc!

[Snagger]

The drilling restriction is probably to ensure the damp membrane isn’t pierced.

[miketomcat]

I would get a quote for filling the holes in the floor professionally. Then you can go to the landlord and offer a refundable deposit for that amount. That way if you don't sort it when you leave he has the money to sort it. I suspect the landlord will be more agreeable if he's sure it's not costing him.

Mike

[Escape]

As @Bowie69 says, there are 4-posters that don't bolt down, but have a wheel at each corner with nothing more than a brake. No frame at the base, maybe the sliders at the posts are designed to take more than just a vertical load but I doubt it, given the price of these lifts (often marketed as movable parking lifts).

I remember when putting up our lifts there were very detailed instructions for bolting down the 2-posters, but not so much for the 4-posters. It's just to keep the legs from spreading and to keep everything in place when driving onto the lift. So an H-frame or even better a triangulated box will do just fine. It wouldn't even have to be that thick as most of the force will be outward so the frame will be loaded in tension. Flat bar should suffice, taking up little space.

[Ed Poore]

Looking at the installation manual for my lift the thing that was emphasises was that you could get away with quite thin concrete provided you had rebar tying all the legs together. I.e. What @Stellaghost has suggested - basically you want to stop the four legs from splaying apart or twisting over.

If you couldn't put rebar in the requirements for the concrete pad in each corner were huge. Something of at least a cubic metre of concrete in each corner provided the ground was good. Compared to a 2-4" slab depending on concrete strength if you had decent steelwork tying the four corners together.

 

 

[toenden]

A friend of mine, had a twoposter mounted on a Steel subframe, no problems. The great thing was, that it could be moved around the workshop as well as outside when washing vehicles. I am not saying it is a correct way to do it, but it worked well. 🙂

My own fourposter is secured to an unknown slab with bolts, but it sure would be nice to be able to move it, from time to time... 

/mads

[landroversforever]

When I've looked at concrete specs for lifts in the past is varies so much from manufacturer, even with a 2-post. Some give loads of info on concrete type/rebar/spacing from edges etc yet others just ask for a flat level floor and no spec. 

For a 4 poster I don't think I'd be overly concerned with it not bolted down as long as you're not wedged in somewhere so you've got escape routes. As mentioned above there are several options for lifts with wheels to move about and a few companies in the states do towable mobile 2 post lifts to take to events like Drag and drive etc. 

[steve b]

1 hour ago, landroversforever said:

For a 4 poster I don't think I'd be overly concerned with it not bolted down as long as you're not wedged in somewhere so you've got escape routes. 

It's comforting to know you have a practical understanding of risk assessment with your day job in the nuclear industry.....

Steve

[reb78]

The steel wouldn't be cheap but if you had a set of flat plates welded together like a square figure of 8 (think of how it looks on a calculator) and secured the lift legs to that, I would think it would be perfectly secure and you wouldn't gain unwanted height (other than the thickness of the plate).  I'd have thought 6-8mm plate, the width of the feet of the legs and the length of the lift would be fine. When installing them you can put them together and raise the ramps to get the legs in the right place to bolt down. The frame/bolts are just to keep everything from splaying. Mines bolted but i dont see the difference between fixing it to a well made frame or bolting it into the floor. 

Edited December 16, 2022 by reb78

[muddy]

Im not sure how many have used a 4 poster but the splaying will only jam it momemterirly and then everything tries to start twisting posts over, some flat bar will do bugger all. I obviously can't comment on your location but any landlord that doesn't want a floor drilling in a commercial application would be a serious worry for me, what are they trying to hide?

 

Bolt it down, work safe and **** the landlord, work out slab depth so you don't pierce any damvproof and fill the holes when finished.

[Carloz]

8 hours ago, landroversforever said:

When I've looked at concrete specs for lifts in the past is varies so much from manufacturer, even with a 2-post. Some give loads of info on concrete type/rebar/spacing from edges etc yet others just ask for a flat level floor and no spec. 

For a 4 poster I don't think I'd be overly concerned with it not bolted down as long as you're not wedged in somewhere so you've got escape routes. As mentioned above there are several options for lifts with wheels to move about and a few companies in the states do towable mobile 2 post lifts to take to events like Drag and drive etc. 

I have two 4 posters and I know that they need to secured to the floor for sure. Of course it will stand without but any movement can make it collapse quite easily.

A simpel square frame from some strong beams (like H-beams 100x100 or something like that) with on the corners the posts secured will do. You need only longer ramps when used for a normal car.

[FridgeFreezer]

My standard method of risk assessment is to ponder whether the scenario would qualify as a typical opening sequence for an episode of Casualty - and I'd suggest that a plucky home mechanic admiring his ingenious DIY solution to his not-bolted-down-properly 4-poster lift while he wanders underneath a 2-ton vehicle suspended in mid-air is a very good fit.

Or to put it another way - please be careful!

[Bowie69]

On 12/15/2022 at 5:05 PM, Bowie69 said:

There are lifts available that don't bolt down at all, in fact you can fit wheels on and push it about.... doubtless they are designed differently to a standard lift.

I feel the need to quote myself here and further highlight the qualification on the end of this sentence!

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