|Climbing wall tech - wall materials|
|The vast majority of modular holds are mounted on 3/4 or 5/8 inch thick plywood sheets. The plywood-modular hold system will almost always give you the most bang for the buck. Plywood sheets can be configured together to form overhangs, roofs, low angle sections, corners, or aretes. The choice between 3/4 or 5/8 inch plywood depends on the type of wall you are building. If you are bolting plywood to closely spaced studs such as a garage wall then 5/8 inch plywood will work fine and is less expensive. You should note that 5/8 inch is the minimum thickness for a wall since you need that much clearance for a standard T-nut. The standard size for climbing walls however is 3/4 inch which should definately be used for roofs, overhanging walls and walls with studs 2 feet apart or greater. Freestanding climbing structures will also greatly benifit from the greater strength and rigidity of 3/4" plywood.
A new material that is gaining popularity for wall building is oriented strand board (OSB). Generally, this stuff is a bit less stiff than plywood, about the same strength, but less than 1/2 the price! I've had good results using OSB to build walls and can recomend it.
Walls made with plywood panels are generally constructed from whole 4 by 8 sheets of plywood attached to some sort of framework. Cutting up sheets into 4 by 4 or smaller pieces is more work but will enable you to fit sheets together with more variations in angles. One advantage of using smaller sheets than 4 by 8 is that they will be lighter which will make attaching them to a framework easier. Putting up and taking down 4 by 8 sheets is definitely a 2 or 3 person job. Plywood sheets are somewhat flexible and this can sometimes be an advantage. Instead of having two 4 by 4 sheets that come together at a slight angle, you can bend one 4 by 8 sheet into a continuous arc for a more realistic surface. Bending plywood sheets also greatly increases their rigidity (sort of the principle behind pre-stressed concrete) which is a desirable trait in a climbing wall.