So spring has arrived, and we have decided to build a 20' x 40' enclosed area in which to place a garden (we have many deer, rabbits and other garden veggie thieves in the area).
The plan is to build a 5' tall fence, using 4×4 cedar for the posts. The posts would be set ~3' into the ground. We are in an area with a pretty active freeze/thaw cycle (Minnesota). The fence panels themselves would be framed metal garden mesh (i.e.- a doubled up 1×4 "frame" with heavy duty wire mesh typically used for horse fences in the center). This should greatly reduce the wind load on the fence, as there will be little surface area.
I went and calculated the amount of quikrete I'd need to set the posts in, and it came to nearly $40/post (5 50lb bags per post). With 14 posts, this ends up being $580 just for the concrete for the fence! After doing some reading, it appears that some fence builders will use 3" of pea gravel as a base under the post, then fill around the post to about 1' below the surface with compacted pea gravel, then do 8" of concrete, topped with 4" of soil. For a garden fence that will have relatively small lateral loads, does this seem to be an appropriate way to do things? Any thoughts on how I should set these posts?
Best Answer
Pea gravel for the base of the hole makes sense...for drainage. On the sides, less so. I'd opt for crushed rock which will compact better when tamping. If tamped properly, you likely don't even need concrete.