Gutter Covers and Leaf Guards - "Not all Gutter Covers Catch all the Water" - Continued

This third post of a series about the ability of gutter covers and gutter guards to collect all the water coming from the roof. The first two posts identified characteristics to look for in solid top and screens that would cause overshooting on any straight gutter.

In this post I'll discuss the most challenging gutter and roof configuration to collect water which is from a roof valley. Typically when two gutters come together at right angles it's from two roof lines intersecting and creating a valley.

The other configuration is a valley formed by a dormer in the shape of an A. In this case the gutter is straight.

With both configurations water from two roof adjacent roofs runs down to the point of intersection which is a valley. The water then flows downward to the gutter and this is where the challenge arises.

Even with uncovered gutters it's sometimes a challenge to catch all the water from a valley. You will often see splash guards installed vertically from the outer gutter lip to keep water that's rushing down the valley from overshooting the gutter.

Because all gutter covers are either solid top or with limited openings, as in screens, the water is all projected to a point in the gutter cover where there are either no or limited openings.

Salesmen of most gutter guards and gutter protectors usually avoid discussing this issue because their solutions are limited to either doing nothing or installing a diverter on the roof to spread the water out across the two adjacent gutter guards.

The problem is that doing nothing is only an option when overshooting at a valley doesn't matter such as if the overshooting water falls onto a bush or a bed of pine needles. But if the water overshoots onto an entrance or walk way then there can be a big problem.


Until the late 90's the only other option was to install diverters which work well in low debris areas. The problem with them is that:
1. homeowners object to the metal standing up on the roof.
2. they get clogged with debris in medium-to-high debris areas rendering them useless and cleaning them from the ground can be difficult.

If you have a valley, when you are looking at having gutter guards installed, it's important to ask about how the water is handled in valleys. There is only one manufacturer of gutter guards in the market place that has taken the problem of overshooting in valleys seriously and actually has working proven devices to spread water without trapping debris.

More in the next post.