If a leak has to start somewhere, it's almost always a corner or end-cap joint — here's why those spots fail before the rest of the run.
A straight run of seamless gutter has no joints along its length, but corners, end caps, and downspout outlets are where separate pieces are joined together with sealant. Every seam is a potential failure point, and corners simply have more of them than any other section of the system.
The metal itself can last decades, but the sealant at a joint has a shorter lifespan — years of sun exposure, temperature swings, and water contact cause it to shrink, crack, and eventually let water through, usually well before the gutter material itself shows any wear.
Metal expands and contracts with Texas's wide temperature swings between summer heat and winter cold snaps. A long straight run distributes that movement evenly, but a corner joint concentrates the stress at a single point, which can work a sealed joint loose over time.
Water dripping from underneath a corner or end cap during rain, or a stain on the fascia directly below a joint, are the most common signs — different from general overflow, which usually shows water spilling over the front edge along a longer stretch.
Most corner leaks are a resealing job, not a full section replacement — the joint is cleaned out, old sealant removed, and a fresh bead of gutter-grade sealant applied. If the corner piece itself is bent or corroded, that specific piece gets replaced rather than the whole run.