The 7 1/2" wide Mountaineer log combines superior durability and strength with natural thermal mass to retain internal heat in winter and deflect external heat in summer. All of our logs feature double tongues for prevention of air and water infiltration. We mill our logs to provide a small overlap at the bottom of each course. This manufactured drip-edge between courses minimizes water penetration and allows a superior surface for caulking as requires. Chinked Special groove on the log exterior provides an area to apply today's special chinking for the rustic appeal of a chinked log home. Double Round Rounded on both exterior and interior to give the classic log home appearance. D-Shaped The most popular profile of rounded exterior with a rain shedding drip edge and a flat beveled-edge interior.