Why Your Gate Sags and How We Fix It

The four causes

• The hinge post leans or is loose. The whole gate hangs off one post. If that post has tipped even a little, or rocks in the ground, the latch side drops. On a wood fence this is the most common cause by far, and it is a post problem, not a gate problem.
• The hinges are too small or have worked loose. A 6 foot privacy gate is heavy. Light hinges bend, and screws in old wood back out. The gate then hangs off the top hinge and drops at the latch.
• The frame has racked out of square. A gate is a rectangle held square by its brace. Without one, or with a weak one, the rectangle slowly becomes a parallelogram: the hinge side stays up, the latch side goes down.
• The brace is missing or runs the wrong way. This one is so common it gets its own section below.

What a photo shows

Stand square to the gate, pull it shut, and take one photo of the whole gate with both posts in the frame. Then one close-up of the hinge post at the ground. That is usually enough to name the cause.

• The hinge post is not plumb against the fence next to it, or the fence panel on the far side of it leans too: the post is the cause.
• The post is plumb but the gate is lower on the latch side, with a wedge-shaped gap at the top: the frame has racked, which means the brace is missing, weak or wrong.
• The gap between the gate and the hinge post is wider at the top than the bottom: the top hinge has pulled or the hinges are loose.
• The gate is square and level but still will not latch: the latch itself moved or bent, which is the cheapest fix of all.

The brace that goes the right way

A wood brace works by pushing. The latch side of a gate wants to drop. A diagonal board that runs from the bottom hinge corner up to the top latch corner carries that weight down into the hinge post, where the post can hold it. The latch corner sits on the brace like a shelf.

Run the board the other way, from the top hinge corner down to the bottom latch corner, and it does nothing but add weight. The latch side keeps dropping, now with a brace on it. We see this on gates every month, often on gates somebody rebuilt to stop the sag.

A steel cable kit with a turnbuckle is the opposite case. A cable works by pulling, so it runs from the top hinge corner down to the bottom latch corner, and tightening the turnbuckle lifts the latch corner. A cable is a fair fix for a gate that is square and has a sound post, but it is a band-aid on a gate with a bad post or loose hinges.

How we fix it, in order

The order matters. A new brace on a gate that hangs from a leaning post is a brace on a leaning post. So we go from the ground up.

1. The post. If the hinge post leans or rocks, it comes out and a new ground-contact post goes in, set in concrete with gravel under it and crowned on top. The gate waits for the concrete to cure before it goes back on, which can mean a short second visit the next day.
2. The frame. The gate is pulled square and the brace is set the right way. A badly racked or rotted frame is rebuilt from new rails and the old pickets where they are still good.
3. The hardware. Hinges sized for the weight of the gate, through-bolted where the wood allows, and a latch that catches when the gate swings shut. Hinges that were fine often go back on; the ones that bent do not.

Most gate repairs are one visit, $225 to $600, installed, plus tax, confirmed after the final measure. A gate that needs a new hinge post sits toward the top of that range, because the post is the bigger job. If the fence next to the gate leans too, read repair or replace.

Latches, closers and pool gates

A plain gravity latch is fine on a back gate that only you use. A gate to the street, or any gate a child can reach, is better with a latch that cannot be bumped open and a spring hinge or closer that shuts the gate behind whoever forgot. We fit both.

A gate into a pool yard is a special case. Most towns have rules on a pool barrier: how tall it is, how big the gaps can be, and that the gate closes and latches on its own, with the latch high enough to be out of a small child's reach. The rules differ by town and county, so check with yours before you change a pool gate. For a frameless glass pool fence and its gate, our sister company Carolina Glass Railing installs those.