12' - 0" Building W
idth
To keep 2x4 frame from
moving, toe nail to 4x4.
4x4 Treated Runners
2x4 Joist 11' - 9" Long
2.
Cut 2x4-12' floor joist to 11'-9". Treated lumber may be thicker than 1-1/2". Take this into
account when cutting the length of floor joists. Shorten joist measurements if necessary to
obtain 12'-0" building width.
Door W
all
1.
Cut (2) two 2x4 joist headers to length. Cut 2x4s to 12'-0" for a 12' long building, 16'-0" for
a 16' long building. Layout for 16" on center joist spacing. 'X' marks where floor joist will
be placed.
4x8
Flooring
Material Description
12' x 12' shed
12' x 16' shed
2x4 Joist Headers
2 pcs.
12'
2 pcs.
16'
2x4 Floor Joist
10 pcs.
12'
13 pcs.
12'
4x4 Treated Runners
4 pcs.
12'
8 pcs.
8'
Flooring 5/8" or 3/4"
5 pcs. 4x8
6 pcs.
4x8
Screw Floor Nails
2 lbs.
8d
2 lbs.
8d
Galv. Box Nails
1 lb. 16d
2 lbs.
16d
Joist Header 12'- 0" for 12' building
16'- 0" for 16' building
X
X
X
X
X
X
16"
15-1/4"
2x4 Joist Header
X
X
16"
It is important that the floor be level and square. Square the floor as follows: before nailing the
flooring, measure the floor diagonally (corner to corner). Then measure the opposite corners.
These measurements will be the same if the floor is square.
When using a concrete slab for a floor, use the same overall foundation measurements. Install
foam sill sealer as a moisture barrier between the concrete and the wall plates. Foam sill sealer
can be purchased at home centers in rolls 3-1/2" or wider.
4x8
Flooring
4x4
Flooring
12' - 0" or 16' - 0" Length
Constructing Details for Deluxe Floor System
Deluxe floors include 4x4 runners, standard floors do not
Check local building codes in your area, the construction may have to change. For a concrete slab,
install sill sealer as a moisture barrier between the concrete and the wall plates. Foam sill sealer can
be purchased at home centers in rolls 3-1/2" or wider.
