How to Build a Post and Pier Foundation
- 1). Outline the perimeter of the foundation and set a pier block at each corner and at 8-foot intervals around the perimeter. If you plan to run beams through the middle of the foundation rather than hanging joists from joist hangers, set blocks at 8-foot intervals inside the perimeter.
- 2). Dig a hole for each pier block so that 1/2 to 2/3 of the block is underground. Tamp the bottom of the hole with a tamper and use a torpedo level to be sure the top of the pier block is level. Back-fill the hole with concrete mix and let it set.
- 3). Attach metal post brackets to the top of each pier block by nailing them in place with 1-1/4-inch nails. Some pier blocks have these pre-set into the concrete.
- 4). Set a 4-by-4 post into each bracket and nail the bottom to the bracket with 1-1/4-inch nails.
- 5). Determine the height of the floor, taking into account the width of the beams and the thickness of the flooring, and use a line level to level the tops of the posts relative to each other at the correct height. Cut the posts with a hand saw or circular saw. Attach a 4-b-4 X 4-by-6 beam holder to the top of each post, orienting the holder in the beam direction and nail it in place with 1-1/4-inch nails.
- 6). Set beams into the holders and, plumbing the posts with a level as you go, nail them in place. If it is necessary to join beams, do it at the midpoint of a post and nail both beams to the holder.
- 7). Nail 2-by-8 joist hangers to the insides of a pair of facing beams at 16 to 24-inch intervals if you have set no beams in the middle of the foundation. Then set the joists in the hangers and nail them in place. Use 1-/1/4-inch or joist hanger nails for both connections.
- 8). Toe-nail the joists to the tops of the beams if you have set beams in the middle of the foundation.
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