Timber Garden Gate
A solid braced or slatted garden gate that opens and closes properly for years. The single most common point of garden timber failure — done right, it lasts decades; done wrong, it sags within a season.
What you'll need
Materials
- Frame stock (47×95 or 47×120mm typically), boarding or slats for the face, diagonal brace, stainless or heavy galvanised T-hinges or strap hinges, latch hardware, optional cap rail.
Tools
- Drill/driver, mitre or hand saw, spirit level (long), square, clamps (essential — at least two long), tape measure, hinge fitting drill bits if mortising.
Material complexity: Medium
Buy one spare board and a little extra frame length. Hinges are bought as a pair — get the heavy ones.
Main risk: A gate that is not braced and through-bolted will sag within a season — this is the most common garden-timber failure.
Cut list
Default 900×1800mm boarded gate. Measure the posts, not the old gate, before you cut.
- Stiles ×247×95mm × 1800mm (the two uprights)
- Rails ×347×95mm × 806mm (900 minus two 47mm stiles) — top, middle and bottom
- Compression brace ×147×95mm × about 1700mm, cut to fit from the bottom hinge corner up to the top latch corner
- Boards ×8–9: 18×100mm × 1750mm
- Optional cap rail ×147×70mm × 900mm, sloped to shed water
- Hinges: one pair of 300–450mm T-hinges (use 450mm on oak or iroko)
- Through-bolts: M8 or M10, two per hinge leaf into the stile, and matching bolts into the post
- Latch and keep to suit the post
- Stainless or coated screws 5.0×70–80mm for the frame; 4.5×40mm for boards
Step-by-step
Measure the opening and pick the hinge side
Measure between the finished posts, not an old gate. Subtract 5–10mm each side for clearance. Decide which way it swings before you cut — into the garden is the usual, more secure choice.
Tip: The hinge post must be plumb and solid. If it moves, fix the post first.
Cut the frame and dry-fit the brace
Cut two 47×95mm stiles at 1800mm and three rails at 806mm. Lay them on a flat floor and check the diagonals. Cut the brace to run from the bottom hinge corner up to the top latch corner. That direction is not optional.
Watch out: A brace the wrong way is in tension. It will pull the joints open and the gate will sag.
Assemble square, then board it
Screw the frame together, two screws per joint, then fit the brace. Fix 18×100mm boards with a slight overlap or a tight butt, keeping 25mm from ends. Add a sloped cap if you want the top rail to last.
Tip: Build the gate flat on saw horses. Trying to assemble it hanging between posts is how frames go out of square.
Hang it on 300–450mm T-hinges, through-bolted
Offer the gate in the opening on blocks so you have 50–80mm underneath. Mark the hinges. Through-bolt each leaf to the stile with M8 or M10 bolts, two per leaf. Fix the other leaf to the post with matching bolts or long coach screws into sound timber.
Watch out: Short woodscrews in the stile will tear out. The leverage on a 1.8m gate is huge.
Fit the latch and watch it for a season
Fit the latch so it catches without lifting or dropping the gate. Re-tighten every hinge bolt after the first month, then again after the first winter. Lubricate with marine grease twice a year.
Tip: If the gate starts to scrape, do not plane the bottom until you have re-tightened the hinges and checked the post is still plumb.
Tips & traps
- Brace running the wrong way — from the latch bottom up to the hinge top — so it pulls the frame apart.
- Hinges only coach-screwed, not through-bolted.
- No clearance under the gate — it drops and scrapes in year one.
- A skinny, leaning hinge post.
Planning & timber detail
Why build this?
A garden gate is the most-used piece of timber on a property. Done right with a braced frame, oversized hinges and a finish you refresh, an oak or iroko gate lasts decades. Done wrong, it sags within a season. The small details separate those two outcomes.
Where it works best
Hung from a solid, plumb post (75×75mm minimum, 100×100mm preferred for taller gates). The post matters more than the gate — a bombproof gate on a wonky post still sags.
Planning notes
Decide hinge side from which way the gate should swing — into the property is more secure; into the street is rarely permitted. Self-closing hinges add safety for pool or pond enclosures.
Typical sizes
Default hung-from-fence side gate: 900×1800mm, 47×95mm frame, 18×100mm vertical boards.
Allow 5–10mm each side of the posts and 50–80mm under the gate so it never scrapes as it drops a little in year one.
Default dimensions
Default: 900mm wide × 1800mm tall.
Frame: 47×95mm stiles and rails.
Clearance: 5–10mm each side, 50–80mm under the gate.
Hinges: 300–450mm T-hinges, through-bolted.
Design variants
Close-boarded (this page) — 18×100mm vertical boards on a 47×95mm frame. The usual side gate.
Slatted — same frame, 38×19mm battens with gaps. Lighter look, less wind load.
Oak or iroko — same sizes, more weight. Use the 450mm end of the hinge range and through-bolts, not coach screws alone.
Suitable timber options
Oak — beautiful, heavy, decades of life. Iroko — slightly less weight, comparable durability, more affordable. Cedar — light, easy to work, less durable but pleasant on a low-use back garden gate. Treated redwood — utility gates only.
Fixing and finishing
Through-bolt the hinges to the gate stile — coach screws alone are not enough for the leverage. Use 300–450mm T-hinges and M8 or M10 through-bolts, two per leaf. The diagonal brace must run from the bottom hinge corner up to the top latch corner — it works in compression. Reversed, it is in tension and pulls the gate apart.
The diagonal brace MUST run from the bottom hinge corner UP to the top latch corner — it works in compression. Reversed, the brace is in tension and pulls the gate apart. This is the single most-missed detail in DIY gates.
Maintenance
Lubricate hinges twice a year with marine grease. Re-tighten hinge bolts after the first season. Re-oil before the finish goes chalky.
Drop a drop of marine grease on hinge knuckles each season. Replace any hinge that becomes stiff or rusty — they're cheap and the gate's lifespan depends on them.
Timber behaviour
Durability
UC3 minimum throughout — UC3 means timber kept off the soil (above ground). UC4 only if the bottom of the gate ever touches the ground, which it should not. Keep 50–80mm under the gate at all times so it cannot sag onto wet soil.
Movement
A gate that doesn't accommodate movement WILL sag or stick. Use a properly braced frame with a diagonal compression brace from the bottom hinge corner UP to the top latch corner. This is the single most important construction detail.
Go deeper
Related yards
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