Replace a broken fence slat by removing the damaged board, cutting a matching new one, treating it, and nailing it back in place.
FS-01Check the damage and gather your toolsLook closely at the broken slat and work out if it's a lap panel (horizontal overlapping boards), featherboard/closeboard (vertical tapered boards), or picket. Push gently on the panel either side of the break to check the rest of the frame is sound. Wear gloves — old fence timber often has splinters, rusty nails and sometimes wasps or spiders behind it.
FS-02Remove the broken slatUse a claw hammer or flat pry bar to lever out the nails or staples holding the slat at the top, middle and bottom rails. Pull the broken pieces free, then remove any leftover nail stubs from the rails so the new slat sits flush. Work slowly so you don't crack the boards either side.
FS-03Measure and cut the replacement slatUse the old slat as a template for length, width and thickness — measure twice before cutting. Buy a matching board (feather-edge, lap or picket, depending on your panel type) and cut it to length with a panel saw. If the timber is pressure-treated, try to match that too, so the new slat weathers at the same rate.
1 each · Replacement fence slat (matching profile, ~1.8m)
FS-04Treat the cut endsBrush wood preservative or end-grain sealant onto both freshly cut ends of the new slat. This is the part most likely to rot first if left bare. Leave it to dry fully — check the tin, but 30–60 minutes is typical — before fixing the slat in place.
1 tin (250ml) · Wood preservative / end-grain treatment
FS-05Fix the new slat in placeLine the new slat up to match the overlap of its neighbours — for featherboard, that's usually a 20–30mm overlap. Nail into each rail (top, middle, bottom) with two galvanised nails per rail, offsetting them slightly so the timber doesn't split. Use exterior wood screws instead if the board feels like it's splitting as you nail.
FS-06Check the fix and tidy upPush and pull the new slat to make sure it's firm and doesn't flex on its own. Sweep up sawdust and offcuts, and wrap old rusty nails and the broken slat before putting them in the bin. Keep any leftover preservative and offcut timber for next time.
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