1.
Stagger the 4x4 timbers as shown below. Cut (2) two 2x4- 8' boards into 2' long blocks
to secure the 4x4s where they butt together.
Assembly Instructions for
Rear Floor Section
4.
Install the floor joists cut above between the 8' joist headers. Secure with 16d galv. deck nails.
5.
Place floor assembly over the 4x4s. Square floor assembly. Measure the floor diagonally
(corner to corner) and then the opposite corners; these measurements will be the same when
the floor is square. Toenail frame (headers & joists) to the 4x4 runners.
2.
Cut (2) two 2x4-8' to a length of 8' -0". They
will be used for the joist headers. Layout, from
left, for 16" on center joist spacing. 'X' marks
where floor joist will be placed.
6.
Cut (2) two 2x4-12' to a length of 12' -0". Layout
for 16" joist spacing, See above.
7.
Install floor joists between the joist headers. Square
the floor section and install against the section
assembled above. Toenail to the 4x4s runners.
8.
Install 4x8 flooring over the 2x4s. Use 8d galv.
spiral nails spaced 8" apart.
Material Description
12' x 20'
2x4 Treated Blocking
2 pcs.
8'
2x4 PT Joist Headers
2 pcs.
8'
2x4 PT Joist Headers
2 pcs.
12'
2x4 PT Floor Joist
17 pcs.
12'
4x4 Treated Runners
4 pcs.
8'
4x4 Treated Runners
4 pcs.
12'
Flooring 5/8" or 3/4"
8 pcs. 4x8
Galv Spiral Floor Nails
3 lb.
8d
Galvanized Deck Nails
5 lb.
16d
Foundation size is 12'-0" x 20'-0". 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.
Constructing Details for Deluxe Floor System
3.
Cut (17) seventeen 2x4-12' treated boards to 11' -9". These will be the floor joists. 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.
X
X
X
X
X
X
X
X
X
X
15-1/4"
16"
16"
4x4-8' Treated
Runner
4x8 Flooring
2x4-8' Joist Header
4x4-12' Treated
Runner
4x4-8' Runner
4x4-12' Runner
4x4-12' Runner
Front Floor Section
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