While a smaller commercial building might be able to get away with 5-inch box gutters, we generally recommend that you start by looking at the 6-inch sizes. This is because commercial buildings tend to have more water built up on them than residential buildings, meaning the gutters need to be larger.

Every metal building should be equipped with gutters and downspouts to divert water away from the structure for the following reasons: Protection from Getting Wet: Imagine trying to enter or leave your metal building when it's raining outside. Without gutters, you would get drenched.

Gutters collect and transport water runoff to areas that don't interfere with the building's infrastructure or entryways. Three main types of gutters include half-round, k-style, and box gutters. Box gutters are especially popular for commercial buildings and flat-roofed buildings.