Expert: Michael Curry - 6/23/2011

Question
Hi Michael.

A number of years ago a built a shed that is 22' x 16'. Unfortunately, being an amateur at this, I did not install the proper foundation and the structure has settled over the years. I am attempting to have the problem rectifed and would like some advice as to how to remedy this situation. The old foundation consisted of concrete cinder blocks that were just laid on the ground at 4 foot intervals and four 4 x 4 pressure treated beams, 16 ft long were placed on the blocks approx. 5 feet between each beam.   The floor is framed with 2' x 8' with 16" spacing. It is covered with 3/4 " plywood. The land slopes from front to back with about 16" difference in elevation from front to back of shed. My intentions are to lift the shed from its current footing, install proper concrete footing/support and then lower it back on the footing. How deep in the ground would you suggest would be sufficient for the concrete and how should it be positioned??

Answer
Hi Terry.
With the size of that shed I'm sure it would require a foundation similar to a house or garage. This would be a poured concrete footing well below the frost line which in Newfoundland could be as much as 6' and then either poured or block walls. I cannot tell you the sizes you would need as that requires engineering but most houses and garages have a 24' x 6" footing and 8" wall. Make sure you allow for proper venting under the floor as that area will now be closed. Another way may be to pour some piers but one again I can't advise you on the size and location. An engineer or architect could give you all the specifics.