Hinges and Gate Posts That Keep an Old Gate Hanging True

A heavy gate is supposed to swing level and latch on its own weight. Often it drags a corner across the pavement instead. In Austin, TX, the cause is usually underground, and wrought iron gates austin rex theater galax sets the order of checks deliberately, starting with the post rather than the gate. A frame can be perfectly square on the bench and still sag within a year if the footing under it moves. Hinges get blamed first, but they mostly show a problem that began lower.

Why Austin soil moves a post

Much of the city sits on expansive clay that swells in a wet spring and shrinks hard in a dry August. The clay lies over limestone along the Balcones Fault, where the Texas Hill Country meets the blackland plain, so the depth to rock changes block by block. A post set in a shallow hole in clay rides up and down with the seasons, and a post that hits a limestone shelf partway down may not have been set deep enough at all. The result is a post that leans a degree or two toward the swing side.

Reading a sag

The crew starts with a level on the post, both faces. A post leaning toward the gate is a footing problem. A post that is plumb with a gate that hangs low points to worn hinges or a frame that has racked. Measure the gap along the latch side from top to bottom, because a wedge shape means the frame is out of square, and an even gap that has simply dropped means the hinge pins have worn. A single swing gate carries all its load on one post, which is why it fails first.

Hinges and pins

A worn pin gives a gate a quarter inch of play, and that adds up at the far end of a wide leaf. Replacement hinges are matched to the gate weight, with a bottom thrust bearing for anything heavy so the load sits on a bearing and not on the knuckle. The top hinge is adjustable, which lets the crew pull the leaf back into line once the post is set right.

Resetting the post

When a post has moved, the fix is a new footing, not a push back into plumb. The old concrete is broken out, the hole is taken below the active clay layer, and the post is set with a belled base so the soil cannot lift it. Steel tubing posts are better filled with concrete to keep water out of the core. The concrete cures for several days before the gate goes back on, since a green footing will move again under the leaf weight.

Rehanging and testing

With the post true, the gate is hung, shimmed and swung through its full arc. The latch should catch without lifting or pushing the leaf. Any weld repair to the frame is ground, primed and painted before it is closed up.