Tongue & Groove 1/2" - 21

This 1/2" - 21 tongue & groove siding measures .500" thickness, requiring any sized wide blank of four-quarter lumber for milling on an industrial molder. The blind-nailed profile contains a 13/64" tall by 33/64" wide groove on the right. The tongue side retains a 5/8" wide by 13/64" thickness with a .008" void in the joint area for expansion and contraction of the wood during seasonal changes in relative humidity. When two pieces of milled lumber join, they create a decorative 1/8" channel/gap between the merged boards. We offer an alternative profile with similar design characteristics for your review and consideration, tongue & groove .500" - 12.