Gate Dropped And Dragging On The Ground

What's happening?

A gate that drops has almost always lost its diagonal. A gate leaf is a rectangle, and a rectangle has no inherent resistance to being pushed out of square: what holds it is the diagonal brace, which must run from the bottom of the hinge side up to the top of the latch side so that the gate's weight is carried in compression down onto the hinge. Fit that brace the wrong way round and it does nothing; let the joints loosen and it stops working. The other half of the problem is at the post: a gate hangs off a lever arm, so a hinge post takes far more load than a fence post of the same size and it leans towards the gate over time. The give-away is where the gap has changed. A wider gap at the top of the latch side means the leaf has racked; a gate that has moved as a whole unit means the hinge post has tilted.

What usually causes it?

• The diagonal brace missing, or fitted the wrong way round so it cannot carry the load in compression
• Loose or failed joints in the gate frame, letting the leaf rack out of square
• The hinge post leaning towards the gate because its foundation is too small for the leverage
• Hinge post rotted at ground level, so it is bending rather than holding
• Hinges undersized for the weight of the gate, or their fixings pulling out of the timber
• Screws used where coach bolts through the frame were needed, or a leaf swollen with damp that has become heavier and larger
• Ground or paving heaving upward under the swing, so the gate catches without having moved at all

Is it dangerous?

Low risk in itself, though a heavy dragging gate can trap fingers as it jams and swings, and a gate that no longer closes is a security and containment problem rather than a safety one. It matters much more where the gate is the barrier keeping a child or a dog off a road, driveway or pond: a gate that will not latch is not a barrier. A large timber gate with failing hinges can also come off its fixings, and those are heavy enough to injure someone.

Can I fix it myself?

Diagnose with the gaps. Close the gate and look at the gap down the latch side: if it is wider at the top than the bottom, the leaf has racked and the brace is the problem. Then push the hinge post: if the whole gate moves, the post has gone. Check whether the brace runs from the bottom hinge corner up to the top latch corner, because a brace the other way is decorative. Tightening bolts, replacing screws with coach bolts and adding or reversing a brace are reasonable DIY. Resetting the hinge post is heavier work and is what usually needs doing on a gate that has dropped twice.

When should you call a fencing and gate installer?

Call a fencing and gate installer if the hinge post has moved or is soft at ground level, if the gate frame joints have opened up, or if the gate is heavy and the hinges are pulling out. Also call where the gate is the barrier keeping a child or animal away from a road or water: that needs to close and latch reliably, not nearly. If the gate is automated, do not adjust the leaf or hinges yourself; the safety forces are set to the gate as installed and moving it changes them.

What will the fencing and gate installer actually do?

• Measure the gaps and check the leaf for square to separate a racked gate from a leaning post
• Check the brace direction and reinstate it running from the bottom hinge corner to the top latch corner
• Re-glue, cramp and bolt the frame joints, or rebuild the leaf where the joints have gone
• Excavate and reset or replace the hinge post with a foundation sized for the leverage of the gate, not just the fence
• Fit hinges rated for the weight and width of the gate, bolted through the frame rather than screwed
• Rehang the gate to consistent gaps with the correct ground clearance, re-align the latch and keep, and ease any paving that has heaved into the swing

Who fixes this

• Gate repair and rehanging

Questions people ask

Sources & References

1. BS 1722-7, Fences: specification for wooden post and rail fences
2. Wood Protection Association
3. Planning Portal: Fences, gates and garden walls