This is an extension of an earlier instructable where we built a 2 1/2 sheet dead-vertical indoor climbing wall (left in the picture). Six months later we set out to expand the woody with a roof section and an invert. wall. The technique, tools and materials are the same, but this expansion requires more complex framing (which some commenters claimed was a limitation of the last instructable).

As before, here's what you'll need:

Some 3/4" plywood (subflooring grade) - $20-ish a 4x8 sheet
Some 2x4s (or 2x6 or 2x8) for framing and such - $2-ish per 8'
2" (or so) wood/drywall screws
3/8" t-nuts (about 70 per sheet of plywood) - $0.15-ish a piece for galvinized
3/8" hex cap bolts
Drill, hammer, saw
Something soft to work as a crash-pad
Beer...lots of beer

Step 1: Framing

How you frame will depend on what types of features and wall-angles you want as well as the area in which you chose to build. We made use of the 16-on-center 2x12 rafters in the ceiling for the majority of support as well as a set of over-built shelves that were on the wall from a past life.

Some things you might want for the framing:

Nails and a hammer (we had a pneumatic nail gun - yay)
Nail-plates - good for joining 2x4s
Skillsaw or a handsaw and a lot of patience
Level
Tape measure, square

Because a climbing wall faces dynamic loads in strange directions, it's not bad to overbuild it. Since we used the rafters for the primary support, it was natural to frame out at 16-inch intervals, clearly overkill, but that's okay.

In the photos you can see how we framed out the invert. wall, extended the crack machine into the ceiling, and added an angled box to the roof. The angled box serves two purposes - it adds a great feature and it avoids the careful task of moving a gas line.

Step 2: Sheathing

In this step, you'll prepare the plywood with t-nuts and then install it on the frame. As before, we're using 70 t-nuts per sheet of plywood placed in a uniform but random pattern. We are careful not to put t-nuts where the studs are, and put fewer near the bottom where foot jibs are usually screw-on.

Attaching the plywood is where the 2" screws come in. One screw every foot-or-two is about right. For the horizontal portion of the ceiling we were able to screw directly to the rafters.

Lifting heavy sheets into position can be a bit tricky and you will be rewarded by your resourcefulness. We used a truck jack and a ladder to position one roof sheet, the rest got positioned with a little bit of elbow grease and sometimes a couple shims.

Step 3: Finishing Touches

Six months ago we were too poor to buy holds so we made them from just about anything we could find. This time, we broke down and purchased some commercial holds. Here are hold retailers and some comments:

Entreprise Holds - A nice small company in Bend, Oregon with cheap holds. The red holds you can see in the picture are theirs - the Chain Reaction set.
Metolius - Another company based in Bend Oregon, which is quite a bit bigger. They have a line of wood holds (made in Korea...) which are pretty cheap and are okay. The laquered finish is slippery but gets a little better with use (and chalk). They have some nice plastic holds too, but they are expensive. We have some of each.
You - Make your own damn holds! See here and here.

A pull-up bar is a nice addition too. We used a piece of fence-post and bolted two eye-bolts through it. Another two 3/8 eye bolts easily screw into two t-nut holes and you can use webbing or whatever else (a couple small 'biners were what we used) to get the right extension.

Used mattresses make pretty good crash-pads.

You might want to install some lighting. We had to remove one fixture and install another one.

A full bar and a stereo are also nice additions.