Frost Depth Requirements for Unheated Slab on Grade
Frost Depth Requirements for Unheated Slab on Grade
(OP)
A brief description of the project:
A pre engineered steel frame building. The building is used to assemble heavy power generators. The assembly will take place in the middle of the building on a moving station. The station will move in and out of the building on steel tracks, which extend 20-ft away from the building, so it could be picked up by a gantry crane and placed on trucks. The tracks need 18-in deep foundation and be poured monolithically with 8" reinforced slab. There is no foundation on the perimeter. The column foundations are shallow foundation and extend below the frost depth. The frost depth is 30-inch. And the building is open and not heated. Does the track foundation inside the building need to be to the frost depth? PS I am assuming the track foundation outside the building needs to meet the frost depth requirement.
A pre engineered steel frame building. The building is used to assemble heavy power generators. The assembly will take place in the middle of the building on a moving station. The station will move in and out of the building on steel tracks, which extend 20-ft away from the building, so it could be picked up by a gantry crane and placed on trucks. The tracks need 18-in deep foundation and be poured monolithically with 8" reinforced slab. There is no foundation on the perimeter. The column foundations are shallow foundation and extend below the frost depth. The frost depth is 30-inch. And the building is open and not heated. Does the track foundation inside the building need to be to the frost depth? PS I am assuming the track foundation outside the building needs to meet the frost depth requirement.





RE: Frost Depth Requirements for Unheated Slab on Grade
RE: Frost Depth Requirements for Unheated Slab on Grade
RE: Frost Depth Requirements for Unheated Slab on Grade
RE: Frost Depth Requirements for Unheated Slab on Grade
I guess the slab as well needs to meet the frost depth. 30-inch slab is a lot.
I found publication at HUD for FPSF: http://
Do you recommend using this guide?
RE: Frost Depth Requirements for Unheated Slab on Grade
How fussy is the cart and contents for exactly being level?
If you reinforce things so that differential frost action won't result in "faults" between slab sections (and it will crack sometime), can you live with some uneven floor and track elevations?
Take a look at the cost of doing all that "frost depth stuff" and you may find you can live with a moving slab, dependent on the seasons.
How's come you know the frost depth is 30 inches? If you have clean sand, it may go much deeper maybe, but won't heave. If you have clay, it probably will heave some, but frozen depth may be only 12 inches. What is the local history with slabs on grade?
I'd step back before doing all that work and think about it.
Closed cell insulation does wonders if you really are fussy.
RE: Frost Depth Requirements for Unheated Slab on Grade
I think you hit it right.
If is very important that the cart and content are exactly leveled to the point that they have hydraulics to level it up. That being said, there are some limitation to the hydraulic movement, and they don't want the slab/foundation to heave and don't want uneven floors.
I looked at the cost of all "frost depth stuff" and it is very expensive, and that is why I turned it to you guys to help me find a less expensive way of doing it.
As for the frost depth, it was determine by a geotechnical report. And the soil under is silty sand.
Anymore information about the closed cell insulation?
RE: Frost Depth Requirements for Unheated Slab on Grade
A possible insulated section:
About 6" NFS at bottom as there weill be very small amount of frost penetration through the insulation, plus a smooth subgrade is needed to place the insulation. Then 2" board insulation. Then 12" NFS over this. Six insulations would probably be enough (thermally) but is difficult to compact just a 6" lift over insulation.