blindnailing

Blindnailing is a woodworking fastening method in which nails are driven so that their heads are not visible on the finished surface. It is commonly used with tongue-and-groove boards, especially hardwood flooring and paneling, to achieve a clean appearance while still providing a secure attachment. In flooring, nails are driven at a shallow angle through the tongue of a board into the subfloor; the nail head sits below the surface of the board or is hidden by the groove, so the surface shows only wood grain and joints.

This technique helps allow for wood movement and seasonal expansion and contraction without visible fasteners. It also produces a smoother, more uniform top surface and can reduce the risk of surface damage from nail heads. Proper execution requires careful alignment, appropriate nail type (often finish or flooring nails), and precise angles to avoid splitting the wood or missing the substrate.

Advantages of blindnailing include a cleaner aesthetic, reduced surface marring, and a more consistent finish on floors and paneling. However, it has limitations. The method demands accuracy and experience; misdriven nails can split boards or fail to hold. It can be difficult to adjust or remove boards once nailed, and not all wood species or substrates are suitable. In cases where blindnailing is impractical, builders may use face-nailing, hidden fasteners, or adhesive systems as alternatives.