Frost Depth in IBC?

[BSVBD]

In Wisconsin's Pre-IBC, "Old" Code, "DILHR" (Department of Industry Labor and Human Relations), it says "Footings and foundations shall be placed below the frost penetration lever, but in no case less than 42 inches below adjacent ground." (Please see attached...)

[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1485701624/tips/Wisconsin_Frost_012917_qb1hwk.pdf[/url]

In Wisconsin's DOC (Department Of Commerce) WCBC (Wisconsin Commercial Building Code) Chapter 18, which, reportedly, corresponds to The 2000/2006 International Building Code (IBC), there is a map, which, in comparison to the "Old" 42" code requirement, is impractically deeper. (Please see attached...)

We need to know exactly how much engineered fill must be brought to the construction site.

Can anyone please refer me to a written document which specifies the required frost depth, especially for Wisconsin?

(I realize I can contact local authorities, but, it is Sunday and they are not open, and that is often a frustrating effort.)

Thank you!

 

[JStephen]

Sometimes, those local requirements are posted online. Have you tried city websites to see if they show building codes used, etc?

 

[KootK]

Presumably the map is for unheated structures and, thus, is not fair game for comparison with the 42" requirement.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[dik]

If you extend the map to the Winnipeg area, you have approximately 90"-100" of penetration... We typically use 72". On clear granular and asphalt parking lots, the depth can be much greater.

Dik

 

[JLNJ]

I don't doubt that 42" is not enough in Wisconsin as you go north. I know the maximum depth contours vary greatly in Michigan. The key is "maximum" and not "average annual".

My sources are (more or less in order):

1. Locally adopted Building Code.
2. State Building Code requirements.
3. Geotechnical Report (I always ask for their recommendation as part of the RFQ).
4. Seelye Design Manual. An ancient text, but there is a lot of good information in there, including a contour map of the entire lower 48.