Claire, I have to wholeheartedly agree with Dave here < both of them>. Making a
trap in the floor can be simple AND dangerous. As Davey said it looks as though you have the room for it, As Dave said, this is really work for a structural person. Depending on the size of the
trap < area > you may or my no need to cut through joists. As soon as you do this you are destroying the structural integrity of your
stage, and endangering anyone on it. The
Trap cover, as well needs to be properly engineered; what if someone is rolling a piano across
stage and hit the
trap cover that's made out of floorboards and 3/4" ply ? Disaster!
I would highly/strongly suggest going to a facilities person at your school and inquiring into how to go about the process of getting pros in help design and them implement the design of a
trap system.
I know it may seem like a silly thing to be this cautious about, but believe me as a individual who has worked on both sides of the
theatre world < building them and building IN them> You want a professionally designed and engineered solution for this.
Now if you were purely talking about wanting to
build a
trap into a scenic
element like a
platform that is raised 39" above the
stage floor, that is a completely different and much easier subject as it is a temporary structure, and much easier to control the use of.
Hope that helps.