in mid november, i went to the big box store and purchased trex to start building the raised beds. i got to admit, it was a long time coming, but these beds getting built meant that i would definitely have at least 1/2 of my garden in raised beds by spring 2009.
my basic bed design is 4 feet wide, with the length varying depending upon location in the garden. the first 6 beds have the following dimensions (in feet): 4x16, 4x15, 4x14, 4x13, 4x12, 4x11 - and there is a 4 foot walkway between each bed and each bed will be 11 inches deep.
trex has a few quirks that i learned about once i started working with it.
the first quirk i ran into was the flexy nature that trex brings to the table. so getting a straight cut was a challenge. continuing along the lines of flexy, i was concerned that in the summer, the trex would soften a bit and flex more (along the longer side) than optimal - due to the weight of the dirt in the bed. to overcome that flex, i tied the long sides together with wire to limit the outward flex.
the second quirk about trex is its density. after breaking off several screws, i decided pre-drilling was necessary for success. i do recommend the use of screws that were specifically engineered for trex. these screws have a special shaped head, which eliminates the mushing of trex material as the screw is sunk into the board.
shown here is a typical bed that has its first layer prepped. the bed will be getting a second layer of trex to bring it up to its ~11 inch depth.
the corners are buttressed with 4x4 redwood and the planks along the long side of the bed are used to keep the trex layers from separating as well as serving as the mount point for the nickel wire described above.