Steel Fence Repair

Steel fence comes to us in three shapes. Picket and rail, what most people call wrought iron, is square tube welded into a channel or angle rail. A privacy panel is sheet or plate welded onto a steel frame, so the face is solid. Pipe and ranch rail is round tube welded at the posts. All three stand on steel posts, so a break anywhere in one is a welding repair.

Chain link is not on that list. Neither is wood, and neither is vinyl. Chain link is woven wire hung on a pipe frame and pulled tight, so putting it right means fabric, ties, tension bands and a stretcher, which is another trade using another set of tools. Wood and vinyl do not weld at all. We say no to those three on the phone rather than drive out to look.

A weld needs sound metal on both sides of the joint. The bottom rail on a picket panel is an open channel, so it holds sprinkler spray and rain long after the panel looks dry, and every picket has a cut end sitting down in it. The tell is a rust bloom just above the rail and paint lifting in a line along it. A picket that rattles when you pull it has already lost its weld. Push a screwdriver into the picket bottoms and the base of a post, and where the tool goes through, that spot gets spliced rather than welded.

A post that leans has a footing that turned under it. The panel works as a sail and levers the post sideways, and only the concrete below grade pushes back. Solid runs lean first, since a closed face gives the wind nothing to pass through while a picket run bleeds most of it away. Straightening the panel above a footing that has moved buys one season. We dig the post out and reset it at least 36 inches into concrete, deeper under a solid panel. No published standard sets that number. It is this shop's own practice.

Impact damage sorts into two kinds and each gets different work. A panel pushed out over several feet is a bow, and bowed steel pulls or heat straightens back without losing much. A crease, a flat spot or a sharp kink means the tube wall has folded, and folded steel never returns to its original stiffness, so that section is cut out and a new piece welded in. A vehicle hit moves the post as well, nearly every time, so the footing gets checked before anyone judges the panel above it.

Most repairs are a section, not a run. We cut back to clean steel, build the replacement on the bench to match what is there, and weld it in between the two sound posts either side. Welding destroys the coating for a few inches around every joint, and a fence set in concrete cannot go back in the galvanizing kettle, so the weld zone is ground clean, coated with a zinc rich compound and topcoated. Fresh coating next to weathered coating reads different in daylight.

Coating decides how long the repair lasts. ASTM A123 keys a minimum hot dip galvanized thickness to the thickness of the steel, which puts common fence tube near 45 to 75 microns. Powder over galvanizing is a duplex system, and the American Galvanizers Association puts it at 1.5 to 2.3 times the combined life of both coatings alone. ASTM D7803 is the prep that makes the pairing hold, and its thermal step keeps zinc from outgassing into pinholes. For color, ask for an AAMA 2604 class powder, since 2603 chalks faster in this sun. Those tiers are written for coatings on aluminum, so 2604 names a class of powder and not a rating on the steel.

Patching a run and replacing it are different jobs at a planning counter. A patched run is the fence that was already there. A replacement run is a new fence, and it meets today's rule for the lot it stands on. 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. Inside a city the figure comes from that city's zoning code, and the page for your city names the section. Nothing sets a length at which a repair becomes a replacement, so ask the counter which side of that line your job sits on.

Around a pool the fence is a legal barrier, and the repair has to put it back as one. Health and Safety Code 115923 holds the barrier at 60 inches minimum, allows no more than 2 inches of clearance underneath, passes no 4 inch sphere through any gap, and keeps the outside face clear of anything a child under five could use as a handhold or foothold. A wide bottom rail welded in as a repair can break that barrier on a fence that passed the week before. Send photos down the line from both ends, close shots of what has failed, and the length of the damaged section. Say whether a pool sits inside the fence. Welding repair is C-60 work.