Work problem... need help with possible solution.

[Coyotebutcher]

Hello fellas. Probably not the whining kind of problem you were expecting, but I’m hoping someone out the night have some ideas to help me. Please spit ball here guys, no stupid ideas, any idea might help spark the right idea in another’s head.
The problem is:
We’re planning to build a temporary deck in an area that is a recessed floor, so as to make it easy for scissor lifts to travel throughout the building unimpeded.
Our main idea thus far is 4x6 stringers supporting 4x6 joists, double sheeted 18.5 mm form ply. 16” Centers is what we know will work but we are talking near 15-18k in material.
Alternatively we’re thinking maybe 2x6 at 12” centers but again this is probably close to our limit on load.
FYI a scissor lift will put 225 psi of pressure on any given point in the floor. And obviously we’re trying to keep costs down as much as possible. Safety is the ultimate priority but cheap and fast doesn’t hurt right...?
No need for the obvious LVL or aluma joists 6” centers planked in timbers. $18k is already expensive for a temp floor. Just hoping someone might have an idea to help out. Thanks boys

[bloopbloob]

First off, what is the sq footage of this area? How deep is it recessed? May seem counter intuitive but steel could be an option.... could end up being cheaper. We run large forklifts over structural grating with 4 foot spans....

[^v^Tinda wolf^v^]

Yup bar grating is a great alternative

[JustBen]

Rather than deck the whole thing in, could you make a ramp? And make it mobile so you only need one?

[Trochu]

I'm having a hard time picturing what you're describing, mainly the depth and distance, but would a rig mat with little ramps on each end work?

[silver lab]

We did this very thing but I’m not sure if it would work for you? We used it for a 10,000lb zoom boom with off road tires so they were wide. We had a lot of really heavy duty pallets (blue or orange) you know, the good ones. Two pallets high run opposite of each other and used 3/4 plywood. If you look around pallets are free. Hope this helps.

[BlackHeart]

Not sure of depth or building or other info or how stucturally solid....so here goes one crazy idea that could work:

Fill the thing with sand, plywood, then vacuum truck the sand out and resell it.

Cost for sand hauling and removal might be cheaper.....

[Coyotebutcher]

It’s 25m Long and saw tool shaped from 8.5 to 5.5 m. 600 deep. Or 24” for you Americans. 125 slab under main slab and recessed slab. Sand would really be an option. Steel would probably cost more than lumber. Thanks so far for the ideas. Again temporary (basically 6 months) of use. Occasional 2500lb scissor lifts driving and working on it. Again 225 lb/sq in is the weight rating on the lifts. I’ve almost convinced myself 12” -16” center 2x6 spanning 4’ between stringers would probably be enough with he double sheeting. Keep it flowing though.

[Trochu]

I like the sand idea. I'd probably go with base gravel and skip the plywood and vac truck, just load it back in a truck with a skid steer/loader, seems like a great, easy, cheap solution to me.

[BlackHeart]

136 yards
Could also use sand-gravel
Being in construction, you might even have a use for it on other sections of this project....so might not have to remove it far. In that case the cost is only for relocating it from the hole to the driveway. And the plywood cover. Saving in labour from not building it from lumber. Tear out labour as well

[bloopbloob]

Just saying, don't just dismiss the steel grating idea.... $18000 will buy you a heck of a lot of grating. It doesn't cost as much as you may assume..... Might not hurt to look into pricing. I can check tomorrow but I think my work pays around $300 for a 4' by 20' section. If kept in full sheets you could also sell it pretty easily when you're done. Filling it in will probably be most economical though. Just my 2 nickles...

[kmacisaac]

Is scaffold an option? Fairly cheap to rent and your crew could install it for the task at hand.

[Coyotebutcher]

The main reason I dismiss the backfilling idea is that it is in the middle of a finished interior slab, and access to the area at time of removal will be inside a finished commercial building. Skid steer and heavy trucks won't be able to get there for removal. Also both slabs are close to finished product (carpet tile and ceramic tile to follow) I like the ideas though. The problem with steel grate would be cutting it to size for removal in the end. And basically making waste of it. This is a medium sized commercial job so selling the grate once completed isn't an option. We don't have time to sell pieces of used construction material basically. No offence intended. Otherwise we would just sell the used full length 4x6 and call it a wash. Thanks again guys. I'll pass some ideas along and see if we come up with something.

[bloopbloob]

With winter coming, make it a swimming pool....
I know the expansion as water freezes will risk damage... but maybe if done slowly in layers and let it freeze like that. Pump it out after. Haha just spitballing. Probably horrible idea. But who knows just tossing out ideas. Maybe fill with styrofoam so its not a solid ice block, cover with a plastic polyfill sheet and top with 4" or so of water

[^v^Tinda wolf^v^]

Cheap and fast doesn’t always go as planned especially if people are driving equipment over it, along with liability etc. I move big things over bar grating all the time. I’d go with four foot wide bar grading and expand as necessary using 2x4x.188 hollow structural steel for the horizontal beams and vertical foot posts. Hire a welder, it should be done by lunchtime

[bloopbloob]

Originally Posted by ^v^Tinda wolf^v^

Cheap and fast doesn’t always go as planned especially if people are driving equipment over it, along with liability etc. I move big things over bar grating all the time. I’d go with four foot wide bar grading and expand as necessary using 2x4x.188 hollow structural steel for the horizontal beams and vertical foot posts. Hire a welder, it should be done by lunchtime

Another thought depending on the scope of work and how much movement is frequently required, you could just build moveable platforms to get you where you need, and not have to cover the entire space. Just shuffle as needed... Also, to the OP, just to be clear, the grating is 4'x20' for ~$300, not 4'x6' as you mentioned

[Geraldsh]

How about renting another scissor lift and leaving it in the hole till the job is done?

[BlackHeart]

Fill the space with sealed empty 2L coke bottles instead of sand. Easy to get and easy to remove. Most coke 2l are designed withstand up to 150 PSI before failure. Under plywood they would work as a team to carry most weights. Some compression settling would happen at first.

Perhaps there is a better air filled pressure vessel other know of.

[dmcbride]

The whole thing doesn’t need to be built to carry the weigh of the scissor lift in any position. Build a few mats to move with the scissor lift.

[Ronan_357]

It sounds like a nightmare to deal with, If there’s a way around (what i’d guess is a pool/fountain) use electric boom lifts instead of scissor lifts or make ramps for the lifts to drive into and out of this thing. Or is there a specific reason it has to be a level floor?

[chuck0039]

Even though this would be temporary, and depending on site conditions you may need to have a structural review completed to ensure your design will be suitable. With the way the Health & Safety programs are going now and if this is a work site, OH& S can get involved so you will want to ensure your covered.

[Coyotebutcher]

The ideas so far have received positive feedback. Steel grates are also too expensive. But surprising to me, backfilling with sand was the most promising idea. Thanks for the help guys. Any more ideas are welcome. Leaving a lift inside is the idea being perused currently. No handrail around the hole is the main deterrent, so we’ll keep messing around with ideas.