Answer: Gutters work on the principle of gravity. The gutter, when properly installed, sits on a small angle on the home. That angle causes the water to flow toward the downspout, eventually being carried away from your home’s foundation.
When a gutter goes “off pitch”, it has lost its angle, and therefore the water simply sits still in the gutter. That water has to go somewhere, and will eventually back up into the home or overflow and pour into the foundation. When backing up, the water also rots the wood behind the gutter (known as the “fascia board”), causing the gutter to eventually fall off the home. If the fascia rots, you will have to replace the gutter and the fascia.
Off pitch gutters can be caused by shifting foundations and the elements (including falling branches), but are often caused by clogs in the gutter. Once debris clogs the gutters, the water has nowhere to go, so it sits in the gutter. That gutter that was once around 20 pounds, now weighs over 300 pounds due to the weight of debris and water sitting in it. Eventually, it goes off pitch and has to be replaced