Things to Know About Installing an Unfinished Pine Floor

Wood Grades

• Some people don't think of pine when installing floors because pine is softwood, known for its knots. To some, knots are unsightly and suggest poor quality. However, an unfinished pine floor can be both attractive and durable with or without knots. Deciding on pine flooring comes with an understanding of wood grade. Pine used mostly for flooring are No. 1 and No. 2 common grades. These grades are selected because they do not contain as many knots as other grades. However, grades 3 and 4 can also be used for flooring. Their richer, knotty look is usually chosen when a rustic aesthetic is desired. Unfinished flooring graded with a 5, which is usually used to make subflooring, joists and crates, can also be used to make knotty pine flooring. Don't be afraid to choose a low-grade pine. Rustic and knotty looks can work well for the right design scheme.

Felt Underlayment

• A key to making an unfinished pine floor durable is to properly cover the subfloor with felt. Just as with hardwood floors, installing a 15-pound felt underlayment will provide strength and keep basement moisture from reaching the pine floor. Felt must overlap each seam by four to six inches.

Nailing for Optimal Durability

• Because pine is a softwood, it must be nailed securely, especially wider boards. According to professionals at W.R. Robinson Lumber, boards, most notably those 8 inches or wider, should be faced and nailed to every floor joist, 16 inches on center. Boards less than 8 inches can be nailed to every other joist, 32 inches on center. Nails should be place no less than 3/4 of an inch from the edge of each board. Up to three nails are recommended for boards wider than 8 inches. Placing nails every four to six inches is recommended.

Staining

• While most unfinished pine floors are stained, some can be left without stain. When choosing not to stain pine, it is important to properly seal it to protect it from gouges and moisture problems. A first coat polyurethane sealer should be applied and allowed to dry for 24 hours. A second coat should be rolled on evenly and allowed to dry for another day.