Building log with high thermal insulation characteristics

Claim 1

A wood log of substantial thickness; said log having complementary top and bottom surfaces adapted to stack with complementary surfaces on other logs; one of said surfaces including: a pair of parallel tongues formed thereon to extend along the length thereof adjacent the edges thereof; and a planar surface between said tongue; the other of said surfaces including: a pair of complementary parallel grooves formed therein to extend along the length thereof adjacent the edges thereof to receive the parallel tongues of an adjacent one of stacked logs; and a planar surface between said tongues; at least one vertical slot along the length of said log; each slot opening into one of said top and bottom planar surfaces; thermal insulation material in each of said slots; said slots extending through the major portion of the top to bottom thickness of said log; and at least one metal reinforcing plate nailed to, and extending substantially across, said one planar surface along the length thereof to span said vertical slot.