Footing depth below grade different when in a crawlspace?

[codehelpneeded]

Where I live, the frost depth is 12" below grade and this is the depth I see footings poured. However, would a strip footing or isolated footing need to be 12" below grade for frost protection if it is located under a house and on hard pan?

 

[Energystar]

Is the crawlspace vented or unvented? Either way, I would say no.

 

[Yankee Chronicler]

Are you asking if it needs to be deeper than 12inches, or less deep?

 

[steveray]

Where I live, the frost depth is 12" below grade and this is the depth I see footings poured. However, would a strip footing or isolated footing need to be 12" below grade for frost protection if it is located under a house and on hard pan?

A basement column footing generally is just below the floor….the floor is not typically considered grade…

 

[Paul Sweet]

Here in central Virginia (climate zone 4A) I've found that crawl spaces tend to stay well above freezing. Mine is around 50 degrees even with the cold weather we have had the past couple months (temperatures in the teens during the day and single digits at night). If you're west of the mountains (zone 4C) it should be similar.

 

[Inspector Gadget]

I would consider the crawlspace unconditioned (unless provided information to the contrary.) The footings would have to be below the frost depth for the lowest of the grade of the exterior and crawlspace.

Then again, we have serious freaking cold up here.

 

[jar546]

Where I live, the frost depth is 12" below grade and this is the depth I see footings poured. However, would a strip footing or isolated footing need to be 12" below grade for frost protection if it is located under a house and on hard pan?

Can we assume this is residential? You originally posted this in the commercial building code area and we moved it.

 

[codehelpneeded]

Can we assume this is residential? You originally posted this in the commercial building code area and we moved it.

I guess either commercial or residential.

 

[ICE]

However, would a strip footing or isolated footing need to be 12" below grade for frost protection if it is located under a house and on hard pan?

Of course I am in Southern California where nearly all exterior footings are 24" deep with interior footings at 18"deep. I do wonder when you would have any footing that is less than 12" into undisturbed soil?

 

[Genduct]

I would consider the crawlspace unconditioned (unless provided information to the contrary.) The footings would have to be below the frost depth for the lowest of the grade of the exterior and crawlspace.

Then again, we have serious freaking cold up here.

Actually, that close to the Artic Circle, don't you guys have PERMA-FROST with 2 seasons Fall and Winter?