How do I make a side gate actually secure?

Most break-ins happen at the back of a house because that is where somebody can work without being seen. A locked side gate removes that entirely, and a gate that is tall, solid, properly hung and locked from the inside makes the rear of the property genuinely awkward to reach. It is the cheapest large improvement available to most houses.

Safety

What you'll need

• A gate at least 1.8m high, or trellis to extend an existing one
• Coach bolts with penny washers and nyloc nuts
• A gate lock or long throw bolt, plus a padlock and hasp for the outside if needed
• Hinge bolts or reversed hinge pins (optional)
• Post, postcrete and a spade if renewing (optional)

Step by step

1. Get the height right first.Below about 1.8m a gate is a step rather than a barrier. Adding a trellis or a solid extension to an existing low gate is usually easier than replacing it, and trellis has the advantage of being flimsy to climb on.
2. Check what happens at the top and the sides.A gate is only as good as the fence it sits in. A 1.8m gate next to a 1m fence panel achieves nothing. Look at the whole line and close the lowest point.
3. Hang it so it cannot be lifted off.On an outward-opening gate the hinge pins are accessible. Reverse alternate pins, use hinges with a security cap, or fit a hinge bolt so the gate is held on the hinge side even if the hinges are attacked.
4. Bolt the hardware through, do not screw it.Coach bolts through the stile with penny washers and nyloc nuts on the inside. Screws into softwood, especially into end grain, hold very little. This is the single most common reason gate hardware fails.
5. Fit a lock that works from the inside.A long throw bolt into the post, a gate lock with a thumbturn inside, or a bolt with a hasp and closed-shackle padlock. Nothing to grip and nothing to reach for from outside.
6. Do not leave a hand-hole or a gap at the latch.A gap wide enough to reach through defeats an internal bolt entirely. Board out the gap, fit a plate over it, or move the bolt out of reach of any gap.
7. Make the post solid.A gate is only as good as what it hangs on. A 100mm post set in concrete at least 600mm deep, or bolted to solid masonry. A wobbling post makes every other measure decorative.
8. Remove the climbing aids.Wheelie bins, a water butt, a log store, garden furniture, a ladder or a stack of pallets against the fence or gate. Moving them or locking them costs nothing and it is very often the actual weakness.
9. Light and see it.A PIR light over the gate, and a clear view of it from a window if possible. Cutting back a shrub beside the gate is free and it is what removes the cover.
10. Consider defensive planting instead of anything sharp.A dense prickly hedge — pyracantha, berberis, holly, hawthorn — along the boundary is effective, lawful and good for wildlife. It is the only sharp deterrent worth using, because it is a plant rather than a device intended to injure.

Tips

• Gravel along the path behind the gate is a genuine deterrent, because it is impossible to cross quietly.
• A cheap battery door alarm on the inside of the gate costs very little and puts noise exactly where somebody hoped for silence.
• If the gate is shared access with a neighbour, agree the arrangement in writing and make sure both households have a key — an obstructed right of way causes a different sort of trouble.

Common mistakes

• Screwing a hasp or lock into the gate stile — Softwood screws pull out under very little force, especially into end grain. Coach bolts with washers and nuts on the inside transform the same hardware.
• Fitting spikes or anti-climb paint without thought — Anything intended to injure can make you liable for the injury, including to a trespasser. Anti-climb paint has specific signage requirements and belongs above 2.4m on your own structure, not on a garden gate.

If it doesn't work

Questions people ask