Aluminum fence vs wood fence

These fences do different jobs

Ornamental aluminum looks like wrought iron and behaves nothing like it. It is a see-through fence: it marks a boundary, keeps a dog or a child in, and meets pool barrier rules, but it hides nothing. A wood fence can be the same kind of open picket fence, but most people buy one to screen a yard, and aluminum cannot do that.

So the first question is not about the material. If you want privacy, compare vinyl and wood instead. If you want an open fence that needs no upkeep, this is the right comparison.

Around a pool, the code decides

The 2021 IRC sends pools to the International Swimming Pool and Spa Code (R327.1), and its § 305 sets the barrier rules. Aluminum makers sell styles built to meet them. Ultra Aluminum, for example, sells pool sections in 6 ft lengths at 48, 54, 60 and 72 in, with the bottom rail flush so no picket ends stick out below it.

The rule that catches people out is the picket-spacing one. If the tops of the horizontal rails are 45 in or more apart, pickets can be up to 4 in apart. If they are closer than that (a short fence, or a style with a mid-rail high up), the rails could be climbed from outside. They have to go on the pool side, and the pickets close up to 1¾ in.

A wood fence can be a barrier too. A solid board face counts as a “solid barrier” under § 305.2.3, which allows no handholds or footholds. In practice, the rails face the pool side and the outside stays flat.

Slopes and curves

Aluminum panels rack: the rails tilt to follow the ground while the pickets stay plumb. Ultra Aluminum says its standard sections rack up to 4 in, and it makes rackable and heavy-rackable versions for steeper ground. Catalyst says most of its aluminum and vinyl systems are rackable. Past the limit, panels are stepped down at each post.

Wood has no limit, because it is built on site. You can step a picket fence, rack it board by board, or follow the ground with each picket. Ultra says its panels can be angled up to 30 degrees at each post, and that a panel must never be bent. Wood rails can be cut to any angle.

How each one goes up

Aluminum panels attach in one of three ways. Ultra lists all three. The rails can slot into holes punched in the posts at the factory, which means each post goes in with its panel, one bay at a time. Or the panels hang on rail-end brackets, or on a strap that slides over the post, which lets you set every post first. Wood goes the usual way: set the posts, hang the rails, fix the boards. Any carpenter can repair it later with lumber from any yard.

Both fences start with posts in the ground. Catalyst says its posts go in concrete, and the depth comes from your frost line, whatever the fence is made of. See how deep fence posts should be and the fence post concrete calculator.

Wind, rust and rot

Wind. An open picket fence lets the wind through, so its posts carry very little load. A solid wood privacy fence catches the wind like a sail, and its posts and footings take that load in every storm.

Rust. Aluminum does not rust, and the makers powder-coat it for color and wear. A deep scratch exposes bare metal, so ask the maker for its touch-up paint. Near salt water, read what the finish warranty says about coastal sites before you buy. Coverage varies by maker and by product line.

Rot. Wood fails first at the ground line, where the post stays wet. The species and treatment decide how fast. The cedar vs pressure-treated comparison covers that choice.

Which to pick

Aluminum for a pool, a front-yard boundary, a slope, or anywhere you want an open fence you never have to paint. Catalyst's care advice is a hose and, for heavier dirt, mild dish soap and water.

Wood when you need privacy, when the run has awkward angles, or when you would rather fix it yourself. Price each one from your own quotes in the fence cost calculator, or see how a per-foot number is built in fence cost per foot.