How do I skew nail two pieces of timber together?

Skew nailing — also called toe nailing — is how a piece is fixed when you cannot nail through the end of it: a stud landing on a sole plate, a noggin between studs, a rafter on a wall plate. Done properly it is surprisingly strong. Done badly the nails burst out of the side and hold nothing, and the difference is almost entirely the angle and the entry point.

What you'll need

• Nails long enough to get good penetration into the lower piece
• A hammer of appropriate weight
• A block or an offcut to act as a stop
• A nail punch (optional)

Step by step

1. Set the piece exactly where it goes and mark it.Skew nails pull a piece slightly in the direction they are driven, so it needs a line to be checked against. Mark both sides of the upright on the piece below.
2. Stop the piece from moving before you start.Screw or clamp an offcut against the far side of the upright so it cannot skate. This is the step that separates a neat skew-nailed joint from a piece that has crept 10mm out of position.
3. Start the nail well above the joint.Roughly a third of the way up the piece being fixed, not just above the joint line. Starting too low means the nail exits the end grain before it reaches the lower timber.
4. Angle it around thirty degrees from vertical.Steep enough to get real length into the lower piece, shallow enough that it does not simply run down inside the upright. Aim the point at a spot well inside the lower timber.
5. Set the nail with light taps at a steeper angle first.Start it almost square so it bites, then bring the hammer round and drive it at the working angle. Trying to start a nail at thirty degrees usually just skids it across the surface.
6. Drive it so the point crosses the joint line properly.The nail should cross the joint diagonally and continue well into the lower piece. A nail that stops at the joint holds nothing at all.
7. Work in opposing pairs.One nail from each face, angles crossing. Each nail then resists the direction of movement the other one would allow, and together they lock the joint. A single skew nail is a hinge.
8. Use three or four nails on a structural member.Two from one face and one or two from the other is the usual pattern on a stud. Space them so they are not all in the same grain line, which would split the timber.
9. Punch the heads if the face will be seen or covered.A proud head stops a board sitting flat. Punch it just below the surface with a nail punch.

Tips

• In structural framing, a proprietary metal connector — a joist hanger, a framing anchor, a truss clip — is the specified fixing and a skew nail is not a substitute for one. Skew nailing is for positioning and for non-structural work.
• Two screws driven at the same angles work identically and hold better, at the cost of speed. On a small job, screws are usually the easier choice.
• If the timber keeps splitting, blunt the nail points and move the nails further from the end of the piece.

Common mistakes

• Starting the nail too close to the joint — It exits the side or the end grain of the upright before reaching the lower timber, so nothing crosses the joint and the fixing does nothing.
• Driving all the nails from the same face — They all allow movement in the same direction, so the joint hinges. Alternate faces so the angles cross.