×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Appropriate Footing Frost Depth
3

Appropriate Footing Frost Depth

Appropriate Footing Frost Depth

(OP)
What is the correct point on a footing's depth to be considered below frost depth?
Top of footing or bottom of footing?
Where would I find the code that indicates which of the two is correct?

Thank You!

RE: Appropriate Footing Frost Depth

2
For IBC jurisdictions:

The frost depth is generally not found in Building Codes, but the IBC -ResidentialCode as least states that local jurisdictions shall determine the depth


Bottom of footing is the depth.

RE: Appropriate Footing Frost Depth

TBell47,
Having the bottom of footing below(at least)the frost depth is typical practice if the uplift is a concern (of structural/piping/building/whoever), and if the footing is exposed to frost.  

Uplift from frost is a relatively tricky item, it is from frost heave on the footing bottom surface and adfreeze on side faces above the frost line of the foundation. Putting footing (bottom face) below frost depth eliminates the heave but may not be good enough. Sometimes the adfreeze stress plays a big role. Usually, there should be a calculation to have the downward force (by DL, selfwt of fdn and friction on the foundation below the frost depth) to balance the uplifting force (by frost heave and adfreese stress).

I don't know if any code tells where to found the footing. Local geotechnical companies (if you don't have a soil's report for a project)usually give very good advice.

Hope this helps

RE: Appropriate Footing Frost Depth

Connecticut and Massachussetts codes list frost depth requirements for our states.

RE: Appropriate Footing Frost Depth

Read Thread194-88791. A similar question is addressed there.


                                                Maui

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources