How do I fit a gate latch and lock?

A latch is fitted to a moving object that changes size with the weather. The failures are all the same — it worked in August and will not catch in January — and they all come from fitting the latch to a measurement rather than to the gate in its closed position.

Step by step

1. Fit the gate stop first.A batten on the latch post, or a stop on the ground, that arrests the gate in the closed position. Without it the latch takes the impact of every close and eventually bends.
2. Close the gate against the stop and hold it there.Everything is marked with the gate in its actual closed position, not from measurements taken with the gate open.
3. Mark the latch on the gate first.Set the latch arm or bar on the gate at a comfortable height — around 1m for an adult — and mark the fixings. Pilot drill before screwing.
4. Mark the keeper from the fitted latch.With the latch on the gate, swing it closed and mark where the catch or keeper lands on the post. Transfer that, do not calculate it.
5. Allow movement in the keeper.A keeper with a little slack lets the gate swell and shrink through the year. A tight fit will bind in winter.
6. For a child-safe gate, put the latch out of reach.Above 1.4m, or a two-action latch that has to be lifted and slid. Fit the operating side so a child inside cannot reach through the gate to release it.
7. Add security separately.A padlock hasp or a lockable bolt, fixed with coach bolts through the gate rather than screws, and positioned so the shackle cannot be levered.
8. Check the operation through a wet spell.Test it again after the first proper rain. That is when timber swells and a marginal fit stops working.

Tips

• Galvanised or stainless ironmongery throughout, including screws. A latch is exposed to weather on both sides.
• A drop of light oil on a gravity latch pivot twice a year stops the arm sticking half-open, which is how gates get left ajar.
• If the gate is a pool, pond or road-side barrier, an automatic self-latching mechanism is not optional — a latch that has to be remembered will be forgotten.

Common mistakes

• Fitting the keeper to a measurement — The gate never hangs exactly where the drawing says. Mark the keeper from the latch with the gate closed against the stop.
• No gate stop — The latch then takes the full impact of the gate closing, bends, and stops aligning. A stop is ten minutes and a piece of batten.

If it doesn't work

Alternatives

• Thumb latch (Suffolk latch): Operated from both sides by a thumb plate through the gate. Traditional, needs a hole through the gate, and does not self-latch reliably on a warped gate.
• Automatic gravity latch: The gate pushes the arm up as it closes and gravity drops it into the catch. Self-latching, tolerant of a bit of movement, and the sensible choice for a child or pet gate.
• Ring or drop latch: A simple pivoting bar dropped into a keeper. Cheap, reliable, and not self-latching — you have to close it deliberately.
• Hasp and staple with a padlock: For security rather than convenience. Fit a closed-shackle padlock and a hasp with concealed fixings, over and above whatever latch is used day to day.

Questions people ask