My A-frame ladder is only 8-foot. I got up onto the attic storage from it once and realized I couldn't get back down. That was fun - it was like 90 degrees outside in the shade. That attic was way hotter.
A trip to lowes yielded some 12-foot 2 x 4's and 8-foot 2 x 3's. Then I realized I don't have sawhorses anymore. Son of a...
Some scrap wood outta do. Face-clamped the 2 x 4's (which act as risers) and measured out for notches.
Technically these are dado's. The 2 x 3's acting as rungs will sit edgewise in the dado's for strength. Circular saw, here we go!
They crack out real easy at this stage, and then I clean up the cuts with my chisel. For wood only, dammit.
Look at those pretty notches.
Set these aside, and cut the rungs.
Test fit on the rungs looks good.
Polyurethane glue in the notches. For strength, and its waterproof.
That's a lot of ladder. Should be enough to get on the roof, then it will be converted to a permanent wall-mount ladder about where it is now. It won't be tilted though.
Test run to the roof, the whole point of sweating in the broiling sun building the ladder. It is however about 4-5 degrees cooler where we live than "in the city". In hand you can see the louvered exterior vent I am installing for the new bathroom vent.
See works great for fat folks. Nice and sturdy.
Will varnish it later with some spar urethane.