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Three Bin System

  • For plant trimmings alone, or for fruit & vegetable scraps with plant trimmings 
  • Requires minimum 3'x 9' of yard space
  • Excellent for hot composting, has removable front slats for easy turning, and separate bins for turning and aging compost, and/or storing compostables
  • Can handle large amounts of compostables
  • Carpentry skills needed for construction
  • $175 - $200 for new materials


  • 2x4" wood*: (8) 31 1/2", (8) 36", (4) 9', and (4) 29" pieces
  • 2x6" wood: (4) 36" pieces
  • 2x2" wood: (6) 34 1/2", (1) 9', and (4) 29" pieces
  • 1x6" wood: (19) 31" pieces
  • 1/4" mesh hardware cloth: 30'x3'
  • Carriage bolts (3-1/2"x3/8"): 12, with washers and nuts
  • 12 penny galvanized nails: 2 pounds
  • 8 penny galvanized nails: 1 pound
  • Poultry wire staples: 1 pound
  • Corrugated fiberglass (4 oz.): (2) 8'x26" pieces
  • Gasketed roofing nails: (40)
  • Wiggle molding: 18 feet
  • 3" hinges (zinc plated, galvanized or brass): (3)
  • 4" flat corner braces: (4) with 1" wood screws
  • 4" flat "T" braces: (4), with 1" wood screws
  • (4) hook eyes, and 8' of strong twine or chain

*Bin dimensions based on planed wood.


  • Power saw (use eye protection) or hand saw
  • Drill with 3/8" and 1/16" bits
  • Screwdriver
  • Hammer
  • Tin snips
  • Tape measure
  • Pencil
  • Socket or wrench
  • Carpenter's square.


1. Main Structure

Butt nail two 31 1/2" and two 36" 2x4s together with 12 penny nails to form each of four screen dividers. Cut four 36x33 1/2" wire mesh pieces, and staple (every 4") to frames after checking frames for squareness. Bolt dividers to three 9' 2x4s as shown (inside measurement between dividers should be 31 5/16"). Tack in 29" 2x4s as shown. Staple one 9'x3' piece of wire mesh (every 4") to back of structure, and one 9'x3' piece to the bottom.

2. Slats and Slat Tracks

Nail 2x6s to front of dividers. Nail 34 1/2" 2x2" onto frames as shown. Leave at least 1" for the slats to slide in. The last slat of each bin section needs to be cut lengthwise to fit.

3. Lid

Assemble lid frame as shown, with flat corner and "T" braces on the bottom side. Pre drill nail holes every couple of feet into wiggle molding humps, and attach molding to 9' 2x2 and 9' 2x4 with 8 penny nails. Note position of wiggle molding on 2x4 in drawing. Cut fiberglass into five 32" pieces with tin snips. Pre drill fiberglass and wiggle molding on top of every third hump, and nail together with gasketed nails. Be sure to overlay fiberglass pieces at least one channel wide, and before attaching the last piece, trim off excess fiberglass. Attach lid to frame with hinges. Attach heavy duty twine or chain to lid and main frame with hook eyes as shown (to prevent lid from falling all the way back).

Two Bin Adaptation

You can make a two bin composter by carefully adapting the materials list. drawings, and assembly instructions.