Seamless, aluminum gutter corner joints can leak, whether they are on inside or outside angles, for a variety of reasons. We discuss ways to avoid this happening during installation, and the right questions to consider when evaluating quotes for a new eavestrough system.

Gutter Joints Can Leak Because of Roof Corners

Roofers use timbers from organic, living trees. Sawmills may do their very best to make these perfectly straight, but they do change their alignment slightly as they dry out. You’ll seldom see a contractor up there with a theodolite, set square, or spirit level. As a result roof corners are seldom square.

It follows that a mass-produced gutter corner from a factory is highly unlikely to perfectly align with an organic roof structure. The average eavestrough installer first fits the straight runs leading to it, and then forces a mass-produced gutter corner into position. They then secure the miter with a number of screws and pop rivets, before adding flexible sealer inside over the joints.

How Factory Gutter Corner Joints Start Leaking

Prefabricated gutter corners are highly unlikely to leak immediately after installation. Your average eavestrough installer knows the risks attached to taking short cuts, and adds loads of flexible sealer over the joints. However, these precautions almost inevitably fail after their warranty period expires, that is if you can find them.

• No flexible roof sealant remains pliable forever. It eventually starts drying out on the surface, making it vulnerable to cracking.
• This is not necessarily an issue providing the underlying aluminum joint is stable, and follows the natural alignment of the roof timbers.
• However, and this is the catch, a factory gutter corner is by nature always under tension, and battling to retain its forced right angle.
• Seasonal temperature variations cause the roof timbers to shrink and expand. This strains the sealant until it cracks and starts leaking.

How to Monitor Gutter Corners for Leaks

Gutter corner joints can leak if they are not properly installed. Your best workaround against shoddy workmanship is to spot it during the warranty period. However, the leaks will be gradual, and may only show during heavy rain. Here are a few tips to spot the leaks after the weather has cleared.

• Go outside the house and look up at your gutter corners from below. If you see undue mold under the corners then the joints are leaking.
• Go outside the house and look down at the ground surface directly below the corners. If you see evidence of undue water flows, then the joints are leaking.

We Do Things Differently at Valiant Exteriors

We do things differently at Valiant Exteriors. That’s because we miter all our corners by hand on site, and according to the run of the roof. This results in a manicured, water-tight joint, and a beautiful seamless aluminum appearance that simply lasts longer. Please contact Valiant Exteriors for professional advice on all exterior renovations.

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