how to level metal structure

[FMC]

I need to level a metal grid, 16' x 7', the grid sections are roughly 2'x2' and built of 1.5''x1.5'' 100 wall steel box tube.(full perimeter frame with divisions for grid, all fully welded into a solid unit)
Concrete floor has a slight slope and grid needs to be level, grid will need to support approx 25000 lbs. This is approx 112 sq' at 205 lbs per sq foot, not sure how to calculate weight applied to actual grid?
? will self leveling cement hold up to this small of a contact area, suggestions appreciated! Thanks

 

[rancherbill]

Assuming perfect loading and disregarding intersections, the area of the steel is:
5 pieces 16' = 80'
9 pieces 7' = 63'
Total of 143 linear feet time 2" wide = 3432 sqaure inches of metal

25,000# / 3432 "^2 = ~7.3#/"^2

Seven pound is nothing for self leveling concrete.

Someone please check my numbers.

 

[larry_g]

Is the load dynamic, like driving a heavy rig on it or a machine tool, or static like a hay pile. I would also want to know how thick the leveling compound is? If perty thin and a dynamic load with point pressure then I would not have a lot of faith in the grout.

lg
no neat sig line

 

[FMC]

Thanks Bill and Larry!
Larry, that was my concern, the load is static and the run out is not great about 3/4 at worst spot, I could elevate the base to level and parge the void but maybe there is something better than self leveling for this? I could easily shim it but the point load would be increased.

 

[A_Pmech]

The usual method on such things is to shim with machinery shims to obtain the necessary flatness and then grout the legs / base.

Through bolts of some kind will help keep the shims in place.

 

[FMC]

The usual method on such things is to shim with machinery shims to obtain the necessary flatness and then grout the legs / base.

Through bolts of some kind will help keep the shims in place.

Thanks Pmech, something like a non shrink precision grout from quikcrete? the data sheets look promising

 

[cyamaha2007]

At work we would use steel shims to achieve level. Then tighten the wedge anchors to spec. Lastly pack the void under leg with non shrink grout.

 

[Mach5]

Assuming perfect loading and disregarding intersections, the area of the steel is:
5 pieces 16' = 80'
9 pieces 7' = 63'
Total of 143 linear feet time 2" wide = 3432 sqaure inches of metal

25,000# / 3432 '^2 = ~7.3#/'^2

Seven pound is nothing for self leveling concrete.

Someone please check my numbers.

7.3lbs/sq in. (you have per sq. ft).

 

[FMC]

awesome! yet another hurdle leaped in the most sacrilegious anti garage build

 

[rancherbill]

7.3lbs/sq in. (you have per sq. ft).

I just saw that as I opened up the thread. I changed it and then scrolled down and saw this comment. Thanks for checking, that's why I had asked for a check.

 

[larry_g]

As I read the comments It comes to mind what is level to you? A lot of people confuse flat and level. What tolerance of level do you need. When A_PM talks of bedding in a machine then his idea of level is way different than what some concrete guy is thinking for a floor. Can you give us an idea of what your doing and the specs you have for flat and for level. How do you plan to check level? How do you plan to check flat?

lg
no neat sig line

 

[FMC]

As I read the comments It comes to mind what is level to you? A lot of people confuse flat and level. What tolerance of level do you need. When PM talks of bedding in a machine then his idea of level is way different than what some concrete guy is thinking for a floor. Can you give us an idea of what your doing and the specs you have for flat and for level. How do you plan to check level? How do you plan to check flat?

lg
no neat sig line

Its for an indoor swimming lane, just need the base solid and level on an existing concrete floor. Thanks

 

[larry_g]

Ok then. You have a relatively coarse job to do so I will agree with shimming to level and grouting for fill. In my world of production machines .010" would be good enough for our uses. In the machining world .001" would be on the high side.

I find it interesting how answers are given here when so little is known about the real question and how the answers are skewed to reflect the posters given experience.

 

[FMC]

Hi Larry, interpretation is in the eye of the reader lol,sometimes very hard for an average Joe to describe a technical requirement when lacking the knowledge that would obviously supply the answer, Thanks for your help