Burning Man Shade Structure
gsutter@zer0.org
$Id: shade-structure,v 1.7 2003/10/12 23:39:41 gsutter Exp $


Abstract:
 Construct a 12' x 12' rectangular shade structure, ~8 feet tall,
 using a bolted wood frame and tarp ceiling and walls.


Begin with:

 4 pc. 4x4x8' lumber, $7.74  =30.96
 4 pc. 2x6x12' lumber, $5.99  =23.96
 3 pc. 2x4x8' lumber, $2.35  =7.05
 50 pc. (1 box) 3/8" x 6" zinc plated hex head tap bolt  =17.49
 48 pc. 3/8" nut, $0.06  =2.88
 48 pc. 3/8" x 1.25" dia. fender washer, $0.15  =7.20
 8 pc. 3/8" x 0.75" dia. washer, ~$0.04  =0.32
 12 pc. 18" taut length bungee cord, $1.49  =17.88
 4 pc. 3" heavy duty screw eyelet, ~$0.60  =2.40
 4 pc. 3/8" x 8" eye bolt, $0.87  =3.48
 6 pc. 3/8" x 5" eye bolt, $0.69  =4.14
 28 pc. 3/8" x 2' rebar stake, $0.49  =13.72
 100 ft. good rope  =9.99
 1 pc. 12'x12' (11'4"x11'6" finish size) 18 oz. canvas tarp  =39.99
   (http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=37918)
   (Note: this tarp is poor quality and the finish size measurements are
    inaccurate; substitute a replacement tarp if possible.)
 3 pc. 9'x12' (8'3" x 11'6" finish size) heavy duty silver tarp, $8.99  =26.97
   (http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=30873)

Total $208.43 of parts, + 8.25% tax = $225.63 materials cost.


Tools needed:

 - Drill and 3/8" bit capable of drilling through a 4" board.
 - Saw to cut 2x4 pieces (14 cuts minimum, 22 for a clean finish)
 - 5/8" (?) socket and ratchet wrench
 - Pliers or a 5/8" wrench
 - Hammer for rebar
 - Knife for rope
 - Pencil and Ruler/Tape Measure for layout


Construction:

Cut eight 32" sections (three per board) from the 2x4x8' lumber.  Lay
out, drill and mount 2x6x12' frame on 4x4x8' pillars using 8" bolts
as shown in this top view.  Note that top of 4x4 pillar is 2" below
top of 2x6x12' frame.

        |------------------ 12' o.d., 11' 8 1/4" i.d. --------->
    __  _________________
     |  |  2x6x12'        ---> 
     |  |________________
     |  | 2 | Top   |
     |  | x |  of   |
     |  | 6 |pillar |
     |  | x |-------+
     |  |12'|
     |  |   |
     |    |
     |    |
     |    V
     | 
 12' 3 3/4"
    o.d.,
     12'
    i.d.
     |
     |
     V

Drill and mount 2x4x32" reinforcing sections on each top corner,
butting against the 4x4 pillar and overlapping the 2x6x12' on the
inside.  The 1" washers are for the abutment, and go into the short
side of the 2x4 pieces.  All bolts point outward to avoid cutting
the center tarp.

Drill and mount 8" eyebolts, 2" up from bottom of each pillar.  Once
the structure has been placed, pound rebar through eyebolts to anchor
the posts.

Hang tarp flat inside 2x6 frame using bungee cords.  Be sure to
mount shorter (11' 4") tarp side aligned with shorter (11' 8 1/4")
frame side.  Stretch tarp to outside and bolt through eyelets if
necessary.

Drill and mount pairs of 5" eyebolts pointing outward on 2x6 frame on
sides where tarps will be hung.  Hang tarps from eyebolts; run rope
from eyebolts through tarp grommets and stake out at desired length.
Flag cords to avoid tripping.