Gutters & Downspouts
Because an overflowing rain gutter can cause damage to the roof decking and interior walls, sizing of your rain gutter system is very important. The downspout is the critical competent in a properly drained gutter. Often times a 3×4 rectangular downspout on a 5″ gutter is all that is needed to boost the carrying capacity. The drain hole, also referred to as the outlet, is critical in quickly flowing water out of the gutter and into the downspout. Much like the drain in your kitchen sink.
5″ K-Style Rain Gutter
6″ K-Style Rain Gutter
6″ Half Round Rain Gutter
Half round rain gutters look great but only have a water capacity similar to 5″ K-style gutters. Half round gutters are often the desired look for custom homes and larger estates, but the size of the roof and amount of water to be collected are more than a 6″ half round gutter system can handle. For these reasons you always want a 4″ round downspout with your half round gutter system.
Downspouts come in two styles, rectangular and round, and can be intermixed with any gutter style. The downspout size is usually selected based on the gutter size chosen for your home and can be either a 2×3 rectangular, 3×4 rectangular, 4×5 rectangular, or a 3″ round and 4″ round downspout. On most gutter systems you will find a 2×3 rectangular on a 5″ K-style gutter. However, in some circumstances it is acceptable for a 3×4 rectangular to be installed on a 5″ gutter to increase the capacity when a 6″ gutter size is undesirable.
Rain Gutter Sizing
Use this handy guide to make sure your rain gutter system is up to the challenge of Central Texas heaviest downpours.