Broward County Certificate of Competency 20-WD-21968-X
What causes rust streaks running down the bottom panel of a garage door?
A straight answer for Broward County homeowners, then what you can check yourself and when to call. Free estimate: (954) 906-1715.
Rust streaks on the bottom panel usually come from steel that is corroding above or at the streak and washing down the face of the door. The usual sources are a worn bottom seal that lets water sit against the lower edge, chipped paint that exposes bare steel, and rusting fasteners or brackets.
In Broward, humidity, daily summer rain, sprinklers and salt air speed this up. The nuance is that a streak on the surface is often cosmetic, while rust at the bottom corner bracket or cable end is a safety issue. The two look similar from the driveway.
Why the bottom panel rusts first
The bottom panel takes the most abuse. Rain splashes off the driveway, sprinkler overspray hits it, and water pools along the threshold when the seal is cracked, flattened or missing. Steel doors have a coated finish. Once that coating is scratched or the cut edge at the bottom is exposed, moisture works under the paint and rust bleeds out as orange-brown streaks.
Hardware is the other common source. Bottom brackets, screws, hinges, and rollers are steel, and when they corrode, the rust runs down the panel face with every rain. Near the coast or the Intracoastal, salt air adds to this. Fasteners and track hardware corrode year-round, even on doors that look fine.
The streak can also be a symptom rather than the problem. If the panel's lower edge is rusting from the inside, the metal can thin and the panel may flex or crease. That matters in Broward's High-Velocity Hurricane Zone (HVHZ), where a garage door is the largest opening in the home and relies on its panels and anchorage to hold up under wind pressure.
What you can check yourself
Find where the streak starts
Look up the streak to its source. A screw head, hinge, or scratch points to a surface issue. A streak that starts at the very bottom edge points to trapped moisture.
Inspect the bottom seal
Check the rubber seal along the bottom for cracks, gaps, flattening or sections that have pulled out of the retainer. Water that sits at the threshold will keep feeding the rust.
Press gently on the rusty area
Surface rust leaves a stain and the metal stays solid. If the metal feels soft, flakes, or has pinholes, the panel is corroding through and cleaning will not fix it.
Look at sprinklers and drainage
Check whether sprinkler heads spray the door or water collects at the slab edge. Redirecting a sprinkler is an easy way to cut down on repeat rust.
Look, but do not touch, the corner brackets
Note any heavy rust on the brackets at the bottom corners, where the lift cables attach. Take a photo and leave them alone, because those parts are under high tension.
When to call a pro
Call us if the rust is at the bottom corner brackets, cable ends, tracks or rollers, if the metal is flaking or perforated, or if the door is crooked, noisy or jerky when it moves. Springs, cables and bottom brackets should never be adjusted or loosened by a homeowner. They can release suddenly. Our garage door work falls under Broward County Certificate of Competency 20-WD-21968-X.
If a panel or the whole door needs replacing, expect a permit. Replacing a garage door generally requires one, while small hardware or spring repairs may not. In the HVHZ, a replacement door needs a Miami-Dade NOA or Florida Product Approval valid for the HVHZ, with an impact rating or an approved shutter or bracing system. Verify specifics with your city's building department, and with your HOA or condo board if one applies.
Impact Garage Doors work is done under Broward County Certificate of Competency 20-WD-21968-X (windows, doors, shutters & garage doors).
What a pro will do
- Find the rust source and its extentWe check whether it is surface staining, a failing seal, corroded hardware or panel metal that has rusted through.
- Repair or replace hardware and sealsCorroded rollers, hinges, tracks, cables and bottom seals can be repaired or replaced, which stops the source of the streaking.
- Replace damaged panels or the doorIf the panel is compromised, we look at whether a matching panel is available or whether a full replacement door approved for the HVHZ makes more sense.
- Handle the permit steps on replacementsWhen the work needs a permit, we pull it, schedule inspections and close it out. Anchoring follows the product approval.
Related questions
- Can I just clean and repaint the rust streaks?
- If the rust is only on the surface and the metal is solid, cleaning and touch-up with a compatible coating can slow it down. If the source is a wet bottom edge or corroding hardware, the streaks will return until that is fixed. Rusted-through metal needs a panel repair or replacement.
- Does a rusty garage door affect hurricane protection?
- It can. Corrosion that weakens panels, brackets or track attachment may reduce how well the door performs under wind pressure. An unrated or compromised door is a weak point in a strong storm.
- Does the garage door count for wind mitigation?
- Opening protection is one category on Florida's form OIR-B1-1802, completed by a licensed inspector, and it is evaluated across all openings, including the garage door. Florida law (s. 627.0629, Florida Statutes) requires insurers to offer wind-mitigation discounts, but amounts vary by insurer. You can try the free Wind Mitigation Credit Checker on this site.
- Do I need a permit to replace a rusted panel?
- A full door replacement generally needs a permit, while a hardware or spring repair may not. A panel replacement is a gray area that depends on the scope and your city. Verify with your city's building department before work starts.
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