DEAR POLE BARN GURU: What is the widest clear span I can get with a 20 # live load and a 25# ground snow load. THOMAS in LACEY
DEAR THOMAS: Quite comfortably and affordably 80 foot. I’ve done up to 100 foot clearspans in this loading combination however many truss plants do not have the capability to fabricate or ship trusses 100′ long in one piece.
DEAR POLE BARN GURU: While waiting for my materials to arrive for my Hansen building, I was reviewing the plans for my building saw my loft flooring 2×12’s are notched into the posts which I understand the reasoning. My question is what are the rules for notching posts and still maintaining structural integrity of the post. ED in BETHUNE
DEAR ED: There are some “rules” for notching wood members, however they apply to floor joists and stud walls in conventional light-frame construction, not to columns in post-frame construction. The limitations for notches in columns would depend upon the placement of the notch and the ability of the remaining timber to carry the imposed loads. Columns are subject to forces of bending and compression. In compression columns are very strong and rarely is over 10% of the strength of the column needed to carry the downward loads. As long as the notch is done to insure a tight fit and the connection between the column and the member fitting into the notch is done properly the downward loads will be carried through the column as if it was never notched at all.
In bending the maximum moment (bending force) is going to occur somewhere midway between the supported ends (or in your case between the ground and the loft floor), very little bending force occurs at or near the ends. The remaining column at the notch must be adequate to resist shear forces, however the lateral restraint provided by the rigid floor makes these manageable.
DEAR POLE BARN GURU: My 36 x 56 barn is going to have an entrance door and a 16w x 12h garage door on the 36 side of the building. My question is do I have to have a footer or not on the 36 side to make sure the doors will shut and open in the winter do to frost heave? Thank you. TIM in HUDSON
DEAR TIM: In the event you have an inadequately prepared site, then having a continuous footing and foundation below the doors (and extending past the columns on each side of the doors) might be a good investment. Such a system would need to also be deep enough to be below the frost line, which could make it cost prohibitive.
Sites which have been properly prepared rarely have issues with frost heave. You will want to read the series of articles which begins here: https://www.hansenpolebuildings.com/2011/10/pole-building-structure-what-causes-frost-heaves/.
