A properly designed and sized gutter system can help keep your home safe against water damage. They will be able to handle water from the heaviest of storms without compromising other parts of your exterior. Knowing the basics of gutter sizing and hiring the right contractor can help you choose the best system for your home.
A trusted provider of replacement windows and gutters share things you need to know about gutter sizing.
The Basics
The most common residential gutter sizes are five-inch K-style gutters and 6-inch half-rounds. Both can handle rainfall in most areas. However, you may need to get wider gutters if you live in a place that’s prone to heavy rains.
To determine the ideal gutter size for your home, you need to calculate the square footage of the gutter’s drainage system. If you have a simple, gable-end roof, you only need to calculate each slope. Meanwhile, for roofs with more than two slopes, you need to add up the area of each surface within a drainage area to come up with the total square footage.
Adjust for Two Factors
After computing the total square footage of drainage for each gutter, you need to adjust for roof pitch and rainfall. Roofs with a steeper slope will collect more rain. You can measure pitch using a 2-foot level and a tape measure. Place one end of the level against the roof, level it and then take note of the distance between the roof and the underside level at its midpoint, giving you a 12-inch run. For example, you measured a 6-inch gap, it means that the roof pitch is 6:12. Moreover, the higher the amount of maximum rainfall in your area, the larger gutters you need to get from your general contractor.
Adjusted Square Footage
You’ll know the adjusted square footage by multiplying the drainage area by the roof pitch and rainfall intensity. Roofs with different drainage areas need different gutter sizes and it’s best to choose the largest ones. You can use the chart below to determine the gutter size you need.
K-Style
5-inch: 5,520 square feet
6-inch: 7,960 square feet
Half-Round
5-inch: 2,500 square feet
6-inch: 3,840 square feet
Choose 3JM Exteriors, Inc for quality gutter installation services. We also specialize in siding and window replacement. Call us at (630) 985-6494 or complete our contact form to request a free quote. We work with clients in Lake Forest, Hinsdale and Schaumburg, IL.
