The Basics of Gutter Sizing

Gutter size is an important element of gutter design, considering how unique each home’s gutter requirements are. In today’s post, local gutter installation contractor Patriot Gutters shares an overview of the basics of gutter sizing.

The Importance of Gutter Sizing

Gutter systems should have the capacity to catch rainwater as it falls from the roof, and route it away to proper drainage systems. In addition to capacity, gutter troughs and downspouts both need to have enough headroom in case of unusually high rainfall levels. Choosing small gutter sizes can lead to overflowing gutters, which can lead to damage to the house foundations.

On the other hand, choosing oversized gutters will increase the probability of having standing water in the troughs. Moisture in the gutters can cause premature wear on the caulk and fasteners, which can lead to corrosion and unplanned gutter repairs.

Gutter Profiles

Gutters come in two profiles: K-style and half-round. K-style is the most common gutter profile, which looks like crown moulding when seen from the ground. Many people believe that the name “K-style” is derived from its profile shape (which some claim resembles the letter K), but it’s actually assigned  by the Sheet Metal and Air Conditioning Contractors National Association (SMACNA), with K-style being the 11th in a series, hence the letter K. Half-round gutters, on the other hand, have a traditional U-shaped profile, and are generally seen on traditional homes.

Gutter Sizing

Gutters are sized depending on three factors: the roof’s square footage, roof pitch, and the strongest recorded rainfall in the area. The roof’s square footage takes into consideration the roofing area that will catch rainwater, while the roof pitch determines how fast the water will make it to the gutters. The steeper the pitch, the faster the gutters get filled up.

These considerations are calculated against the highest recorded rainfall in the area—not just the average—for overhead. The chosen gutter profile is also taken into consideration, as half-round gutters generally have lower capacity than K-style gutters of the same size. These factors all add up to gutters that will meet and exceed any home’s gutter requirements.

Patriot Gutters is your leading provider of gutter guards as well as installation and repair services. Give us a call at (405) 701-0909. You can also fill out our contact form to schedule an appointment. We serve customers in Oklahoma City, OK, and surrounding communities.


Filed Under: Gutters
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