The rulebook specifications for the schutzhund wall are just convoluted enough to make building a new one fairly confusing. Hopefully this helps a little!
The rulebook specifies your basic dimensions as:
- Wall length of 1.9 meters (75″)
- Wall width of 1.5 meters (59″)
It also describes the three cleats at the top of each side as:
- 2" thick
- Top of cleats hitting at 10, 22, and 34 inches from top
It goes on to set the height of the apex (for competition) at 1.8 meters (71"). This translates into a base spread of 1.3 meters (51"). Can’t visualize this? See this diagram.
There’s always been a great deal of variance in schutzhund a-frames. Most use 3/4" plywood and 2×4 framing, although a few are now using steel or aluminum frames rather than wood, since it lasts much longer and you can screw a new "skin" quite easily when the time comes. This has the added advantage of providing better support at a fraction of the weight, since to build a 59" x 75" side, you’ll either need a commercial plywood source or you’ll have to seam the long side. Doing this with 2x4s makes for a very heavy a-frame.
If you have the option (and a building supply store that is well-stocked) use hinges with removable pins to make transport and repair easier. Put a pair of anchors on each side for the chain you’ll use to set the height of the a-frame. Buy pieces longer than you need so that you can take the a-frame low for young dogs or puppy agility practice. (I also believe that starting it low encourages a more sensible, less "airborn" approach to the a-frame.)
My most recent a-frames have had fabricated steel frames, with a 3/8" drop-pin hinge running the full width (secured by a cotter-pin at the end) and side anchors built in. The metal frame allows me to use thinner plywood if I prefer (3/8") with only slightly more flex but the same stability. My next a-frame will also have handles built into each side for lifting.
Some clubs leave their wood rough, others seal, and some paint. A few clubs have even painted their logos onto the sides. My personal preference is to prime the wood, and use an exterior semi-gloss latex of a light, natural color (offwhite or caramel) with grit mixed in for safety. Alternately, you can sprinkle clean white play sand over the sides just after painting, but this adds several steps as you wait for the paint to dry, brush off the excess, and paint again.
Many people also use a piece of indoor/outdoor carpet or turf over the top of the a-frame (under the slats) to prevent injuries where the two sides meet. You can also buy a small piece and roll it, setting it into the gap between sides at the hinge.
Below is a sketch that puts all of this information together: