I'm using I-Joists to span this 27' vaulted living room and create a shed style roof. I've got two problems. Because of the angle, the joist won't make full contact with the walls (short of 20 years worth of settling), and of course it's got a tendency to want to slide. My ideas were to cut angles in the top plates of the walls so that the full surface area bears the load, and to fasten brackets from wall to joist on the outside of both walls to prevent the slide. Do these seem like reasonable solutions? Any better solutions?