I used one sweet gum timber in my house, with no problems. Just did it to be contrary. Had cut it previously for a crosstie but never took it to sell, and it sat outside in the sun for 6 months w/o bowing or twisting, so I used it for a 6x8 jack rafter. Could be mistaken by the casual observer for oak or hickory. Beech and hickory are two other woods that sometmes get a bad rap for timber framing, but I have had success with them too.