Reclaimed barn wood is a beautiful, sustainable building material with a natural patina that can be used in hardwood floors, furniture, crafts and siding. Old barn wood is valuable because it was cut from old growth trees. It has a tighter grain than modern lumber, which makes it stronger and less likely to warp. You should determine the age of salvaged wood and use the information when marketing this lumber or a home containing it. Determine the age of barn wood by examining the way the lumber was cut and assembled.
Examine saw marks on the wood. Irregular, uneven cuts indicate that the builder used a pit saw, a large, long-toothed saw with two handles worked by two men. Wood cut with a pit saw dates from the mid-1600s to the early 1800s. The builder employed a gash saw if the wood shows regular, parallel cut marks. Gash saws, powered by water, date from the early- to mid-1600s. A circular saw, dating from 1860 till present, cut barn wood that displays circle-shaped saw marks. Once you have determined the type of saw used to cut the wood, you can further define the age of the wood by examining the nails and screws used to construct the barn.
Determine the type of nail used to construct the barn. Tapered, pointed nails with four sides were hand-forged from iron prior to 1800. These nails often exhibit a flower-shaped head. Cut nails, made from plates of metal, date to the 1800s. They have two parallel and two angular sides. Wire nails replaced cut nails in the early 1900s. They are round, made of steel, and still in service today.
Look for wood screws, which you can often find near the hinges of barn doors. The first wood screws in barns date to the early 1700s. They are no more than 1/2 inch long and have hand-cut threads. Their ends are flat and they have an off-centre slot on the top. In 1860, builders began using machine-cut wood screws, which are symmetrical with a slot centred on the head.
Check the property records kept by the local government where the barn is located. There may be a record of the barn's construction. Take photos of the barn to your local building inspection office and ask the examiner if he or she can help you determine the age of the wood.