Expert: Bruce E. Johnson - 7/30/2009

Question
I will be building a barn in CT (New England winters are a concern).  The size is 36'x36'.  Which method is recommended and if it's a stem wall what size (width) should the footing and walls be and does the slab go over the wall or inside like a typical basement floor.  If a mono-slab is recomm., is it a 2'x2' perimeter?

Answer
Hi Tom, gosh, without knowing exactly how the barn is going to built, how tall etc.  it's hard to say what size footing you need.  I imagine that a 24" wide by 16" deep footing with three #5 continuous rebar will suffice.  The footing will need to be 36" below grade or whatever the frost line in your particular area.    Bring your stem wall above grade and you can either use a header block at slab level.  (this is an L shaped block that keys the slab into the wall)  or you can do a floating slab (the slab fits inside the stem wall with expansion material attached to the wall).  Either slab is acceptable.   I can't say how well a monolithic slab works up in that cold country but frozen ground has a tendency to move around a bit and may push the slab around.  I suggest you talk to an engineer for final foundation plans and requirements.  I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com