How to Install a Garden Gate
A Complete Step-by-Step Guide for UK Homeowners
If you're building a new fence with a gated opening, install the gate and posts first, then build the fence outward from them. If you're replacing an old gate, measure up carefully to get the exact size you need. Take a tape measure when buying your new gate, as they're sold in both metric and imperial sizes and conversions aren't always accurate. Think about which way you want your gate to open, most open into the property rather than outward.
Preparation
Gateposts for light gates should be approximately 100mm square and 610mm longer than the gate's height. For heavier gates (over 1.2m high or wide), posts should be thicker and at least 760mm longer than the gate height. Always check the manufacturer's specifications.
Treat wooden gateposts with preservative before installation and set them in concrete — post spikes don't provide enough support. Where possible, choose fittings that have been japanned (lacquered) or galvanised to prevent rusting.
Top Tip — Adjusting the Hinges: With some hinges, you may find movement or "play" when screwing them to the gate, making accurate positioning difficult. If so, adjust them after the posts are set. Fit only two holding screws per hinge into the post while it's lying flat. Wait until you've hung the gate before fitting the latch.
Step 1 - Prepare the Post Tops
If your gateposts haven't been weathered, cut the top to a slant so rainwater can run off. Use a sliding bevel to mark a 20-degree angle from the top of the post.
Step 2 - Cut and Treat the Posts
Continue the line square down the face of the post and saw neatly along it. Paint the cut edge with wood preservative. If the wood is untreated, paint the entire post.
Step 3 - Position the Gate and Posts
Decide which way you want your gate to open, then lay it face down on level ground. Place the posts either side with their tops 50mm higher than the top of the gate. Leave a 5mm gap on each side so the gate can open and close freely. Use two timber lengths to raise the gate slightly so it sits in line with the gateposts. Adjust as needed with timber off-cuts or wedges.
Step 4 - Mark and Drill for Hinges
Place the hinges into position on the back of the gate. Mark the screw positions and drill one pilot hole. Test by driving in a screw to check the drill bit isn't too large, then drill the remaining pilot holes.
Step 5 - Attach the Hinges
Screw the hinges in place using galvanised screws. If you find it tricky to position them accurately on the post, wait to fit them and the latch until you've hung the gate.
Step 6 - Fit the Latch
Drill pilot holes for the latch screws, then screw the latch into place. Remember to allow a 5mm gap between gate and post.
Step 7 - Brace the Assembly
Brace the gate and posts with three lengths of timber to ensure the construction is solid. Use the braced gate to mark the position of the post holes.
Step 8 - Dig the Post Holes
Use a spade or post-hole borer to dig your post holes roughly a spade and a half wide, and deep enough to leave a 50mm clearance gap beneath the gate so it can open freely. Gate posts should generally be buried to a depth of 1/3 to 1/2 of their total length underground, with a minimum depth of 2.5 to 3ft.
Check this is sufficient by laying a spirit level on the ground where the gate will open. Level the ground if needed. In soft ground, dig a trench between the post holes about 300mm wide and 200mm deep, then fill with concrete. This prevents the posts being pulled inward by the gate's weight. Lower the gateposts into the holes, using a spirit level to check they're in line.
Step 9 - Concrete the Posts
Use timber props to hold your gate and posts in position. Mix the concrete, then set the posts into the ground. Slope the concrete surface downward to direct rainwater away from the wood.
Step 10 - Allow to Set
Let the concrete set for 48 hours before removing the props and brace.
