Planning on a timber frame with 2 layers of 5″ eps, staggered joints over cathedral ceiling. This will have 2/4 sleepers on top of eps running up roof for a vented roof. I am concerned about using canned foam between joints as I have been reading about shrinkage, settlement of frame, etc. causing foam joint to crack. Any thoughts or experience using something like foam sill seal between joints? Roll it out along edge of slab, slam next slab against it. Should be flexible enough to move with the house. Any suggestions on a better product to use?