Gate Hanging and Hardware: A Fitting Guide

Summary

Gate hanging looks like a simple job and is one of the most common callback generators in the fencing trade. A gate that swings freely and closes square on the day of fitting can be dragging on the ground within six months if the hinge size, post stability, or clearance gaps were wrong from the start — and by then the timber has usually taken the blame when the fault was in the hardware selection or the foundation underneath the hinge post.

This guide covers hardware selection by gate type and weight, the hanging sequence and clearance measurements, and the diagnosis and fix for a sagging or dragging gate. For post foundation depth calculations, see fence post installation depth. For material specification on metal gates and railings, see metal railings and gates. For motorising a gate, see electric gates installation and electric gate installation pricing guide.

Key Facts

• Hinge post depth — same one-third rule as fencing: minimum depth = above-ground gate height ÷ 3, deeper in clay or exposed sites — see fence post installation depth
• Hinge post section size — always oversized relative to standard fence posts on the same run; 100×100mm minimum for a standard garden gate, 125×125mm or larger for driveway gates
• Hinge post concrete — minimum 300mm diameter hole, C25/30 concrete, full depth — hinge posts bear significantly more lateral load than a standard fence post due to the cantilevered weight of the open gate
• Hinge types — strap hinges (traditional timber gates), field gate hinges (hook-and-band, heavy field/driveway gates), ball-bearing hinges (heavier gates, smoother long-term operation), rising butt hinges (self-closing light gates)
• Hinge sizing by gate weight — light garden gate (<15kg): standard T-hinge or strap hinge; medium gate (15–35kg): heavy strap or hook-and-band; heavy driveway gate (35kg+): hook-and-band or ball-bearing, sized to manufacturer weight rating
• Latch-side clearance — 10–15mm gap between gate and latch post for swing clearance and seasonal timber movement
• Ground clearance — 20–50mm typical, more on sloping ground or where the gate must clear grass/gravel
• Double gate leading leaf — needs a drop bolt into a ground socket (usually a bolt sunk into a small concrete-set steel socket) to lock the standing leaf before the operating leaf is latched
• Gate stops — a fitted stop (post-mounted or ground-mounted) prevents the gate swinging past 90° and straining the hinges
• Self-closing hardware — spring hinges or hydraulic closers for gates required to self-close (pool/child safety compliance, some planning conditions)
• Metal gate fixings — A2/A4 stainless steel for outdoor exposed fixings; galvanised mild steel bolts corrode and stain timber over time
• Diagonal bracing — timber gates need a diagonal brace running from the bottom hinge-side corner to the top latch-side corner to resist racking (sagging into a parallelogram shape)

Quick Reference Table

Detailed Guidance

Choosing and sizing hinges

Hinges are selected by gate weight and the loading pattern, not by which hinge happens to be in stock. Under-sized hinges are the single most common cause of early sag — the hinge itself bends or the screws pull out of the timber under a cantilevered load the hinge wasn't rated for.

• Strap hinges — the traditional choice for timber garden and side gates. A strap hinge distributes load along a length of the gate rail rather than at a single point, which suits the typically lighter, wider construction of a picket or panel gate. Fit two for a light gate, three for anything over roughly 20kg or 1.8m tall.
• Hook-and-band (field gate) hinges — the standard for metal field and driveway gates, and for heavy timber close-board gates. The hook is set into the post, the band bolts to the gate frame, and the design allows the gate to be lifted off for maintenance without unbolting anything. Always sized to the manufacturer's weight rating, not "the biggest one available."
• Ball-bearing hinges — used where smooth, low-friction, long-term operation matters — heavier decorative gates, gates that see frequent daily use, or any gate destined for motorisation later (motors work harder against friction from a poor-quality pin hinge).
• Rising butt hinges — self-lifting hinges that raise the gate slightly as it opens, useful for gates that need to clear a rising path or need a mild self-closing action; not load-rated for heavy gates.

Hanging sequence

1. Confirm hinge post stability first. Do not hang the gate on a post that hasn't fully cured (minimum 24 hours for standard concrete mix, longer in cold weather) or on an existing post you haven't checked for rot or movement at ground level.
2. Mark hinge positions on the post — typically 150–200mm from the top and bottom of the gate frame, evenly spaced for a third hinge if fitting one.
3. Fit the hinges to the gate first, on a level surface or trestles, so both hinge halves are square to the gate frame before offering it up to the post.
4. Offer the gate to the post with packers (timber offcuts or shims) supporting it at the correct ground clearance and latch-side gap while you mark and fix the post-side hinge plates.
5. Fix top hinge first, check the gate swings without binding, then fix the bottom hinge.
6. Fit the latch and stop once the gate is confirmed swinging correctly and closing at the right position against the latch post.
7. Fit a diagonal brace on timber gates if one isn't already built into the frame — running low on the hinge side to high on the latch side, which is the geometrically correct direction to resist the gate racking downward at the latch corner over time.

Clearances and gap allowances

Getting clearances wrong causes two different failures. Too tight, and seasonal timber swelling (particularly in winter/wet conditions) causes the gate to bind on the latch post or drag on the ground. Too loose, and the gate looks poorly fitted and, on a latch gap, may not engage the latch reliably.

• Latch-side gap — 10–15mm is the standard working clearance for timber gates, allowing for seasonal movement; metal gates can run tighter (6–10mm) since they don't swell with moisture
• Ground clearance — 20–30mm on a level hard surface (patio, driveway); 40–50mm where the gate crosses grass, gravel or an unfinished surface that may rise over time
• Hinge-side gap — typically minimal (5–10mm) since this side is fixed to the post and doesn't need swing clearance, only enough to allow the hinge to operate without binding

Diagnosing and fixing a sagging gate

A gate that has begun to drag or sag has one of three root causes — diagnose before replacing parts:

Gate sagging / dragging — diagnosis
│
├── Does the whole gate lean, post included?
│   └── YES → Post foundation failure (post moved in ground)
│       → Fix: excavate and reset post to correct depth/diameter,
│         see [fence post installation depth](/knowledge/fencing/fence-post-installation-depth)
│
├── Is the post still plumb but the gate frame has racked
│   (become a parallelogram — top corners no longer square)?
│   └── YES → Frame racking, usually missing/failed diagonal brace
│       → Fix: fit or replace diagonal brace, hinge-side-low to
│         latch-side-high; re-square frame with a temporary brace
│         before permanent fixing
│
├── Is the frame square and the post plumb, but the gate has
│   dropped at the latch corner only?
│   └── YES → Hinge failure — bent hinge, pulled screws, or
│       undersized hinge for the gate weight
│       → Fix: replace with correctly-sized hinge (see table above);
│         if screw holes are stripped, plug with glued dowel and
│         re-drill rather than using longer screws in the same holes
│
└── Does the gate operate fine but won't latch cleanly?
    └── YES → Clearance/alignment issue, not a structural fault
        → Fix: adjust latch plate position or packing shims;
          check ground hasn't risen (mulch, resurfacing) reducing
          clearance

Double gates and locking

Double leaf gates need one leaf (the "standing" leaf) secured independently of the latch, using a drop bolt that engages a ground socket set in concrete below. Without this, the whole load of anything pushing against the closed gates transfers through the latch mechanism alone, which will fail over time. The ground socket must be concrete-set at the correct position — measure and mark before the driveway surface (block paving, tarmac, gravel) goes down, since retrofitting a socket into a finished surface is significantly more disruptive.

Metal vs timber gate hanging differences

Metal gates (mild steel, wrought iron, aluminium) generally hang on hook-and-band or ball-bearing hinges welded or bolted to the gate frame, rather than screwed hinges as with timber. The hinge post for a metal gate needs to resist a more concentrated point load than a timber gate's strap hinges spread along a rail — oversize the post section or consider a masonry pier with a resin-anchored hinge pin for heavier metal gates. See metal railings and gates for full material and fabrication specification.

Frequently Asked Questions

Why has my client's new gate started dragging after only a few months?

Almost always one of three causes: the hinge post has moved slightly in the ground (check plumb against the original fitting position), the timber has swollen with seasonal moisture and is now binding on a clearance gap that was too tight from the start, or an undersized hinge has begun to bend or pull from the timber under the gate's actual weight. Follow the diagnosis sequence above rather than guessing — replacing hinges on a gate that's actually a post foundation problem won't fix it.

How many hinges does a gate need?

Two is standard for light garden and picket gates. Three hinges are recommended for any gate over roughly 20kg or 1.8m tall, and are standard practice for close-board, panel and most driveway gates — the third hinge (usually positioned centrally) significantly reduces the racking load on the top and bottom hinges and reduces long-term sag risk.

What size should the hinge post be compared to the rest of the fence run?

Always larger than the standard run posts on the same fence line. If a fence run uses 75×75mm posts, the hinge post should be at minimum 100×100mm — the hinge post carries a cantilevered load every time the gate is open that a straight fence post never experiences, and undersizing it is a common cause of leaning gates even when the hinges themselves are correctly specified.

Can I add a self-closing spring hinge to an existing gate?

Usually yes, provided the existing hinge posts and gate frame are in good condition and the gate isn't already at the weight limit of its current hinges — a spring hinge adds cyclical stress the original hinges may not have been sized for. Check the gate's condition and hinge rating before retrofitting, and consider whether a hydraulic door closer (more common for pool-safety self-closing gates) is a better fit than a spring hinge for a heavier gate.

Do I need planning permission or building control sign-off for a garden gate?

No, generally not — gate installation itself isn't Building Regs notifiable work. Height restrictions apply the same way as fencing (2m maximum without planning permission away from a highway, 1m adjacent to a highway) — see planning permission fences walls for the full detail on when permission is required.

Regulations & Standards

• No specific British Standard governs domestic gate hanging or hinge sizing; hardware selection follows manufacturer weight ratings and established trade practice rather than a statutory specification

• The Town and Country Planning (General Permitted Development) (England) Order 2015 — height limits for gates as boundary structures (2m general, 1m adjacent to highway)

• BS 8500 — concrete specification, relevant to hinge post foundation mix

• Where a gate is motorised, see electric gates installation for the applicable machinery and electrical safety standards

• Planning Portal — Fences, gates and garden walls — height and permission rules

• TRADA — Timber gate and fencing guidance — timber selection and construction detail

• BSI — BS 8500 concrete for foundations — concrete specification for gate post footings

• Manufacturer hinge and hardware weight-rating data sheets — the authoritative source for matching a specific hinge product to gate weight

• fence post installation depth — post depth and foundation calculations shared with gate hinge posts

• metal railings and gates — metal gate material specification and fabrication

• electric gates installation — motorising a gate, safety compliance

• electric gate installation pricing guide — pricing an automated gate installation