Some other installers might use pre-made corners. Pre-made corners may be installed by someone who may not be proficient at hand mitered corners. They have more seams, requiring more caulking and are more likely to start leaking. The cleanest and neatest corner would be a hand mitered corner, done well. Our installers are all trained on how to install a very good hand mitered corner.
We can provide an industry leading warranty for you because our installers are well trained to provide you with a top-notch installation. Most corners are 90 degree, inside or outside corners, but there also non-standard angles such as on turrets and bay windows.
The installer measures the length of the eavestrough required, cuts a 45 degree angle on each side and brings together to make a 90 degree corner. One side is smooth and the other has tabs cut into it. Our installers screw these together, trim the edges, hammer to smooth any rough parts and caulk using a special Geocel sealant. Unlike other products this sealant is not affected by temperature so need to worry that the weather is too hot or too cold on your installation day. Geocel can even tolerate a bit of moisture.
Remember, we are not a roofer that does eavestroughing. We specialize in eavestroughs and have done so for over 20 years.
The type is pretty small on sealant can but here is what it says ” 2320 Gutter and Narrow Seam Sealant is a single component, extremely durable, flexible tripolymer sealant that forms a watertight seal in small joints and narrow seams. 2320 can be applied under any weather conditions, even through standing water or on oily surfaces. Guaranteed adhesion to metal, glass, vinyl, brick, stone, concrete , wood and asphaltic materials.”
This picture shows examples of inside and outside hand mitered corners done by North Shore Eavestroughing.