How to Make a Quadrat

quadrat schematic quadrat schematic

Download these instructions (pdf 130KB)

Supplies: All supplies can be purchased at your local hardware store

  • ¾” Sch (schedule) 40 PVC (quantity: at least 2.2 m for each quadrat)
  • ¾” 90 degree angle PVC elbows (quantity: 4 per quadrat)
  • PVC primer
  • PVC glue
  • Nylon string (quantity: 5m per quadrat)
  • Hack Saw
  • Drill and 1/8” drill bit
  • Matches, lighter, glue gun or candle
  • Meter tape
  • Vice
  • Hammer and nail
  • Tape
  • Pencil
  • Latex gloves
  • Old newspaper

Instructions

  1. Cut the PVC (use extreme caution when using a saw) into the correct lengths about 0.48 m each, it may vary slightly some elbows may fit more snugly than others.
  2. Make sure you are in a well-ventilated area, preferably outside! Prior to gluing, assemble the PVC lengths with the elbows to insure correct length, when all sides are aligned properly mark the PVC at the point where it meets the elbow. When you glue make sure the elbow lines up with the line again. The insides of the quadrat should measure 50 cm on a side.
  3. Next lay out the newspaper, put on the latex gloves and then primer the inside of the elbow and the outside of the PVC pipe where they will join (approximately a ¼” band on each).
  4. Next put a thin layer of the PVC cement on top of the primer, then put the elbow and the length of PVC together. Make sure the alignment is correct and then let dry (beware, it dries quickly!).
  5. Do one side at a time insuring it is aligned and will lay flat before proceeding, then repeat previous steps until the frame is finished.
  6. Using a meter tape measure the PVC and mark with a pencil (near the center of the inner side) the spot where the holes will be drilled. The holes should be 10 cm apart, thus you will have 4 holes per side.
  7. Repeat until you have marked all four sides.
  8. Once marked, put the frame in a vice so that it will be steady. Take a nail and place it on the mark and tap it until there is an indentation in the PVC. This will make a nice groove and will keep the drill from slipping.
  9. Repeat until all of the spots are marked.
  10. Using a drill, drill holes straight through the two walls of the PVC.
  11. Once all of the holes are drilled, cut a 2.5 m piece of nylon string and place an inch or two wide band of tape on the end. This will make threading the string much easier.
  12. Weave the string through so that you have a nice taught grid!
  13. Okay last step, to insure that the string stays taught and the ends do not fray you can either glue the knot with a glue gun or you can melt the ends of the string by burning the string with a match, lighter, candle or rope burner.

How to Weave the String

  1. Start stringing the first 2.5 m length of string here. Tie knot, pull tight through first hole, then continue to string following the arrows.
  2. Pull string taught, tie knot, then glue or burn knots at both ends.
  3. Turn the quadrat 90 degrees and start stringing the second 2.5 m length of string as above. Tie knot, then continue to string alternately going over and under the first length of string.
  4. Pull string taught, tie knot, then glue or burn knots.
  5. You’re done!