Blind nailing is a fastening technique where nails are driven into a spot that gets covered by the next piece of material, leaving no visible nail heads on the finished surface. It’s most commonly used when installing hardwood flooring and lap siding. The nail is hidden either by the tongue-and-groove joint of the next board or by the overlapping course above, giving you a clean look without the need for wood filler or putty over exposed nail heads.
How Blind Nailing Works on Flooring
In tongue-and-groove hardwood flooring, each board has a protruding ridge (the tongue) on one side and a matching channel (the groove) on the other. Blind nailing means driving a nail at a 45-degree angle through the tongue of the board, just above where it meets the face. When you slide the next board into place, its groove locks over the tongue and completely hides the nail.
The angle matters. At 45 degrees, the nail passes diagonally through the tongue and into the subfloor, pulling the board tight without interfering with the fit of the next piece. If you drive the nail too steeply or too shallow, the next board won’t seat properly, or the nail head may poke up above the tongue and create a gap between boards.
Nail Spacing and Size Guidelines
For standard 3/4-inch-thick solid plank flooring (boards 3 inches or wider), industry guidelines call for 15.5, 16, or 18-gauge cleats or staples at least 1.5 inches long, spaced every 6 to 8 inches along the length of each board. Each board also needs a fastener 1 to 3 inches from every end joint, with a minimum of two fasteners per board regardless of length.
Narrower strip flooring (under 3 inches wide) uses the same fastener sizes but slightly wider spacing of 8 to 10 inches. The end-joint and minimum fastener rules stay the same. These intervals keep the floor tight to the subfloor without over-fastening, which can crack thinner boards.
Tools for the Job
You can blind nail by hand with a hammer and a nail set, but this is slow and leaves more room for error. Most installers use a pneumatic flooring nailer, which sits on the tongue of the board and drives an L-cleat or T-cleat at the correct angle with one strike of a mallet on the nailer’s plunger. These tools are available in 16-gauge and 18-gauge models to match different flooring thicknesses.
Smaller pneumatic palm nailers are useful for tight spots near walls and doorways where a full-size flooring nailer won’t fit. They use the same gauge cleats, so the fastener stays consistent across the entire floor. For the very first few rows along a wall (and sometimes the last), there isn’t enough room to position any nailer on the tongue, so you’ll need to face-nail those rows and cover the holes with base molding or filler.
Blind Nailing on Exterior Siding
The same principle applies to lap siding, especially fiber cement planks. James Hardie, one of the largest fiber cement manufacturers, recommends blind nailing as the preferred installation method. Each plank gets nailed near its top edge, between 3/4 inch and 1 inch from the top, and the course above overlaps by at least 1 1/4 inches to cover the fastener completely. Nails should also stay at least 3/8 inch from the ends of each plank to avoid splitting.
Blind nailing on siding keeps fastener heads out of the weather, which reduces the chance of water intrusion and rust staining. Face nailing exposes both the board and the fastener to rain and wind, which can degrade the seal over time. In areas with high winds or hurricanes, some builders add small finish nails (called “pinning”) at the bottom edge of each plank for extra hold, but the primary attachment still comes from blind nails at the top.
Common Mistakes and How to Avoid Them
Splitting is the biggest risk, especially near the ends of boards where the wood has less material to absorb the force of the nail. Using a fastener that’s too large for the board makes this worse. If you’re hand-nailing, drilling a small pilot hole at the nail location prevents most splits. When working near board ends, clamping across the joint before nailing reinforces the wood and absorbs the shock of penetration. Place the clamp pressure on the end grain of the board you’re fastening.
“Shiners” are nails that aren’t fully buried in the tongue, leaving a bump that prevents the next board from seating flush. This creates a visible gap or a ridge in the finished floor. The fix is straightforward: use a nail set to sink any proud nail heads below the surface of the tongue before fitting the next board. If you’re using a pneumatic nailer, adjusting the air pressure up slightly usually solves the problem.
Driving nails at too steep an angle can blow through the thin edge of the tongue entirely, destroying its ability to lock into the next board’s groove. If this happens, the damaged board needs to be replaced. Staying close to 45 degrees and positioning the nail just above where the tongue meets the board’s face gives the fastener enough wood to grip without compromising the joint.
Blind Nailing vs. Face Nailing
Face nailing means driving a nail straight through the visible surface of the board. It’s simpler and faster, but it leaves nail heads exposed. On flooring, those heads need to be countersunk and filled, and the filler can shrink, discolor, or pop out over time. On siding, face nailing exposes fasteners to moisture and looks noticeably worse.
Blind nailing takes more skill and usually more time, but it produces a surface with no visible fasteners at all. For hardwood floors in living spaces and siding on the front of a house, the aesthetic difference is significant. Face nailing still has its place: it’s standard for the first and last rows of flooring where a nailer can’t reach, for repairs where boards need to be secured quickly, and in hidden areas like closets where appearance matters less.