Box Flashing
What is it and why might I need it?
20% of houses that Fox’s Flowrite Gutters installs gutters on have a trim piece on the fascia. This trim piece, sometimes referred to as a shadow board, creates an uneven fascia. Some builders or homeowners choose to put this trim piece on their fascia mostly for looks. The trim piece creates a shadow line on the fascia which gives the fascia some added depth and character. In some cases the trim will add support to the shingles.
A trim piece at the top of the fascia creates a few problems when installing gutters. Mounting on this trim piece means that there will be a gap between the bottom backside of the gutter and the fascia board. This gap can cause the bottom of the gutter to tip in (as seen below) and potentially pull its screws out, causing the gutter to fall off.
The second issue with mounting a gutter on a trim piece is that it limits the amount of pitch that can be put on a gutter; Especially if the gutter is pitching a great distance in just one direction. For example, if the trim piece is a 1x2 at the top of the fascia, then the gutter cannot be pitched more than two inches because it will be falling below the trim piece. After two inches of pitch, the gutter will not have any support along the back of the gutter. Without box flashing the gutter cannot be properly pitched.
Box flashing (Shown in green) will correct these problems. With box flashing the bottom-backside of the gutter will be fully supported. Therefore, the gutter will not tip in and the possibility of the gutter to pulling itself out is eliminated. The flat-consistent fascia allows the gutter to be pitched properly due to the consistent support along the entire fascia. Box flashing creates a higher quality gutter install.
