How do I build a close-board fence?

Close-board is built in place from components rather than dropped in as panels. It costs more in labour and lasts perhaps twice as long, it can follow a slope, and a damaged board is replaced individually rather than by swapping a whole panel.

Safety

What you'll need

• Posts, 100mm x 100mm, mortised or with arris rail brackets
• Arris rails — two for a 1.2m fence, three for 1.8m
• Feather-edge boards, 100mm or 125mm wide
• Gravel boards and capping rail
• Galvanised or stainless ring-shank nails

Step by step

1. Set the posts at no more than 3m centres.Close-board does not need 1.83m bays because the rails span. 2.7m to 3m is normal. Posts go a third of their length into the ground with a concrete collar, as with any fence.
2. Fit the arris rails.Two rails for a fence up to 1.2m, three above that. Mortised posts take the rail ends directly; otherwise galvanised arris rail brackets screw to the post face. The flat face of the triangular rail goes towards the boards.
3. Fit the gravel board next.It sets the bottom line for every board and keeps the feather edges out of the soil. Get it level and everything above follows.
4. Start boarding from one end, thick edge out.Feather-edge boards are thick on one edge and thin on the other. The thick edge of each board covers the thin edge of the one before, so water sheds outwards rather than into the joint.
5. Set the overlap and hold it consistently.Around 25mm of overlap on a 125mm board. Cut a spacer batten to the exposed width and use it for every board rather than measuring each one.
6. Nail through one board only at each rail.One nail per rail, through the thick edge of the board being fitted and into the rail — passing through the overlap of the one behind, but not nailing the two boards together. Boards that are pinned to each other split as the timber moves.
7. Check plumb every few boards.A small consistent lean accumulates fast across twenty boards. A level against every fifth board keeps the run honest.
8. Fit the capping rail and post caps.A capping rail along the top of the boards sheds water off the end grain, which is where boards rot first. Post caps do the same job for the posts.
9. Treat all cut ends and the whole fence.Every sawn end is untreated timber. Brush end-grain preserver on cuts, then treat the whole fence with a preservative or stain once it has weathered a few weeks.

Tips

• Cut a spacer batten to the exposed board width and hang it from the top rail — it sets the overlap hands-free.
• Buy 10% more boards than the calculation says. Feather-edge splits and warps and you will reject some.
• Ring-shank or annular nails hold far better than smooth nails in a fence that moves in the wind.

Common mistakes

• Nailing through both overlapping boards — It locks the boards together, so when they shrink and swell they split along the nail line instead of sliding. One nail per board per rail.
• Fitting boards thin edge outwards — Water runs into the joint instead of over it and the overlap rots from the inside. Thick edge always covers thin.

If it doesn't work

Questions people ask