“Why is this gutter still overflowing? We repaired the caulking at the seams, repaired the downspout. It (the gutter) has been cleaned, so why does it keep spilling over?”
This is a question we received from a property manager regarding a situation we’ve encountered often before. The answer was confirmed on site by one of our gutter division technicians.
If gutters are not working correctly necessary repair may include reattaching damaged or disconnected downspouts or re-caulking leaky seams. In the instance involved with this question, both items had been performed at this particular section of gutter, which was found to still be overflowing. Then, investigation into additional factors occurred.
Bringing a hose up to the gutter and flooding it with water demonstrated the problem.
By doing this we ensure the downspout is draining properly by observing the water level, but it also demonstrates the angle at which the gutter is sitting. This angle can be incorrectly set during installation, or can change as the building settles and shifts over time. Watching the water level rise as the technician pumped it full of water showed that the gutter was sitting at the incorrect angle. Water flowed to the end of the gutter that was capped, rather than to the end with the downspout. Therefore, during heavy rain, the gutter would fill up and spill over rather than flow down and out the drain spout as it should.
My crude pictures demonstrate on a short length of gutter how the water always fills a vessel and yet remains level, regardless of the angle of the vessel (in this case gutter) in which it sits. Take the example above of the second gutter above, and apply it to a long section of gutter, and you get something like this:
During heavy rainfall, water will accumulate faster than it can drain out, especially since the low end floods and fills first, only being allowed to drain once the water level rises high enough to start escaping through the downspout.
Solution: The gutter needs to be removed from the building, and reattached at the proper angle to allow the water to flow down and out through the downspout.