The three-dimensional model you made of poster board or construction paper is now ready to be transitioned to design drawing. Begin with a simple sketch to define the dimensions. CAD or computer aided design software may be used or you can draw it by hand. CAD is not required, if you can define the entire dimension mathematically.
Each joint or edge should be labeled for the exact distance from the last joint. The distance from existing structure such as wall, floor, ceiling is to be referred. Establish distances, angles and dimensions of the entire structure. Take into consideration the thickness of the plywood sheathing, and the wall studs also, considering the width of the anchoring structure and keep sufficient margins.
Lumber: Actual size and Nominal size
In the US, the size of the unfinished wood is called as nominal size, after the wood is plainer and sanded to the actual size. Usually plaining and sanding will scrape off a quarter or half inch from the nominal size. However, plywood has the same nominal and actual size.
In over hanging sections, spacing and size of the joist will dictate the joist span length. Greater span lengths require larger joists.
An engineer is the right person to determine the design specifications for an overhanging wall, as many factors such as strength of the wood, reinforcement of the joists, and the type of anchor has to be considered.
Climbing walls being heavy need really strong support. The support should not only be able to bear the live load of the climbers, but also bear dead load of the wall itself. Live load of the climbers varies with every move the climber makes and at times can be many times the weight of the climber. The stress the wall undergoes requires it to be supported strongly, if the climbing wall is going to be supported by an existing structure. Then you have to make sure that the existing structure is strong enough to support the climbing wall.
Vertical walls transfer all the weight to the floor, but also exert angular force on the joints away from the wall. In steep overhang sections, three forces are acting on the wall; the weight of the wall itself, the climbers weight, and the forces caused by the climber’s movement. It is advised to seek expert’s and specialist’s opinion before proceeding.
The load the wall is likely to be subjected to will determine the type and size of the joists, anchors, and the thickness of wall studs. Existing structure should be strong enough to take the load of the climbers and should hold itself after being subjected to enormous stress exerted by the climbers. In vertical walls the plywood will offer a lot of vertical strength, but the support should be strong enough to take the live load stress, torque, and resist shearing.
Taking expert advice from structural engineers will ensure that all engineering considerations are taken into account and specifications for the material required finalized. Once this is done, you will be better placed to budget for the material required to build the climbing wall.