Johnston Gutter Replacement & Gutter Guard Installation

Miters and end caps: where leaks start

On a seamless system the long runs almost never leak, because there is nothing along them to leak from. Failures happen at the places where the continuous run has to stop or turn. An end cap is a piece of aluminum closing off the end of a run, attached and sealed. A miter is the corner where two runs meet, either formed from a single folded piece or built up from two cut ends. Both rely on sealant, and sealant has a service life measured in years rather than decades. It becomes brittle, the aluminum on either side of it moves with temperature, and eventually a hairline gap opens. The symptom is a steady drip at a corner during any rain, including light rain, which is what distinguishes it from overflow. This is squarely a repair, not a reason to replace a system. The corner is cleaned back to bare metal, resealed properly, and the run carries on. Where it does signal something larger is when several corners are going at once on a system of the same age, since that means the whole installation has reached the same point.