Steel Privacy Fence

A fence post works as a vertical cantilever. Wind pushes on the panel, the panel hands the load to the post, and the post carries it down into the footing. A picket or open panel lets most of the wind pass through, so only a fraction of the load reaches the post. A solid steel panel has no gaps, so the whole face catches it. That is why a solid fence needs a heavier post and a deeper footing than an open panel of the same height.

A solid run changes what we build. It usually means a heavier post section and tighter post spacing along the line. We set gate and fence posts at least 36 inches into concrete, and we go deeper on a solid panel or a wide gate leaf, deeper still where the ground is loose. That depth is this shop's own practice. No published standard sets it.

Height gets settled by code before preference, and which code depends on where the lot sits. A lot inside city limits follows that city's zoning code. A lot outside them follows the county, and in parts of the Antelope Valley a community standards district adds its own rules on top. In unincorporated Antelope Valley, LA County Code 22.110.070 holds a fence to 3 feet 6 inches in a required front yard and 6 feet in interior side and rear yards.

Most of these codes allow less in the front yard setback than along the side and rear lines, and some of them limit a solid face near the street or rule it out entirely. So the first question on a solid run is not the steel. It is which rulebook governs the lot and what it says about a sight-obscuring fence at that spot. The tall solid sections usually belong on the side and rear lines, with a lower or more open run toward the street. Each city page linked below names the section that applies there.

How the height is measured matters as much as the number. Codes in the area measure from the ground at the fence, and the county averages the ground on both sides of it. On a lot that falls across the run, that reads as a different number at every post. A picket panel can be raked to follow the slope. A solid panel cannot rake without opening a wedge underneath, so it steps down the grade, and each step resets the measured height.

Coating is the other half of a fence in full sun. Hot dip galvanizing under ASTM A123 sets a minimum zinc thickness by the thickness of the steel. Powder over that galvanizing is a duplex system, and the American Galvanizers Association puts a duplex system at roughly 1.5 to 2.3 times the combined life of both coatings alone. Ask for an AAMA 2604 class powder. AAMA 2604 is the superdurable tier and 2603 is the basic one, which chalks faster in this sun. Those standards are written for coatings on aluminum, so the honest phrase is an AAMA 2604 class powder.

Pinholes in powder over galvanizing come from a prep failure. ASTM D7803 is the practice for preparing hot dip galvanized steel for powder, and its thermal pretreatment step stops the zinc from outgassing through the film. Skip that step and a new fence comes back speckled. Rust starts at cut ends and weld seams, where the coating runs thinnest, so those edges get dressed and treated first.

Most privacy runs have an opening in them. A solid gate leaf is the biggest wind catcher on the property, and it hangs on hinges instead of resting on a footing every few feet, so we size the gate post and its hardware apart from the fence line. We fabricate the gate in our shop, then set the posts and hang the leaf on site. When a manual gate later gets a motor, UL 325 and ASTM F2200 come into play.

Bring the run length and the height you want. Add your setback lines and photos that show the fall of the ground, and say where an opening goes and how wide. We measure on site, then cut the steel and weld the frames in our shop.