This letter was received in October, 1992 from the engineering firm of Rudin Structures regarding footing requirements.
We have reviewed your letter from the State of Minnesota Department of Administration regarding your compliance with the State Building Code.
At your request, we are furnishing this letter to substantiate our professional opinion that the handicap ramp will not be adversely affected with mud fills located at grade, in lieu of providing footings to the required frost depth. It is our opinion that wood structures of this type are inherently provided with adequate flexibility in their connections to alleviate any additional stress that might be incurred through frost heaving. The cross bracing evaluated by our office did not require the use of frost footings to provide adequate lateral stability. We do recommend, however, that it would be appropriate to review the construction of the ramp on an annual basis to determine if additional shimming below the mud fills is required to maintain the proper slopes of the ramp.
Sincerely,
Jeffrey S. Rudin, P. E.
Senior Structural Engineer
Rudin Structures