 Another rare, historic building technique is for the posts of a timber frame building to land directly on a foundation or in the ground and the sills fit between the posts and are called "interrupted sills".In modern, wood construction, sills usually come in sizes of 2×4, 2×6, 2×8, and 2×10.In stick framing, the sill is made of treated lumber, and is anchored to the foundation wall, often with J-bolts, to keep the building from coming off the foundation during a severe storm or earthquake.