Foundation for modular field office 2

[Hoboneer]

For the purposes of foundation, would you treat a modular field office (think shipping container type with a door and window) as a regular structure and provide footings with a minimum depth for frost per local code?
Or you would you think of it as an "equipment pad" and just do a slab with a perimeter haunch?
The office will be permanent.
Does the code address this anywhere?

 

[Greenalleycat]

I think the answer is obvious
It's a permanent field office - you should design footings as per a regular structure
Presumably frost is an annual event so you'd hardly want this thing to be heaving annually?

 

[HTURKAK]

...........provide footings with a minimum depth for frost per local code?
Or you would you think of it as an "equipment pad" and just do a slab with a perimeter haunch?

Short answer: if the soil frost free material , just excavate the top soil and provide a slab with a perimeter haunch,

Long answer : Pls look Int.Res. Code ,FOR ONE- AND TWO-FAMILY DWELLINGS and provide more info.( frost depth, soil type , GWL ..= to get better responds.

 

[jhnblgr]

Check out shallow foundation design for frost protection.

 

[Hoboneer]

I think the answer is obvious
It's a permanent field office - you should design footings as per a regular structure
Presumably frost is an annual event so you'd hardly want this thing to be heaving annually?

It seemed obvious, but when I started thinking about it in terms of an equipment pad it became confusing. Why aren't we concerned with heaving for equipment pads? What guides the slab with haunch design for those?

 

[Brad805]

This will depend on the rules in effect where the office is located. People still put trailers on blocks at grade if they can get away with it. We see these set on screw piles most of the time. Few want to pay the cost for a frost wall, so most end up skirted with wood framing or a plastic product you can find.

 

[milkshakelake]

@Hoboneer When I did equipment pads for large equipment, like pressure vessels or storage tanks, I had a turn-down slab at the ends for frost protection. It costs slightly more, but not that much. It's cheaper than excavating down to frost depth. However, this only works if your soil is suitable at the intended bottom of footing elevation, like say it's 12" excavation or something. If your soil sucks, you need to dig deeper no matter what, since this is a permanent structure.

 

[canwesteng]

For slabs, usually they are designed to be a raft on the soil, so if it heaves, the equipment moves and tilts, but the slab doesn't break. Modular structures are often just on timber cribbing, as long as they can tolerate some movement, and the timber cribbing is adjusted as needed. Sea can type modules also just put on some prepared granular material.