5-inch vs. 6-inch gutters: why we install 6-inch in the Midlands
A 6-inch K-style gutter holds roughly 40 percent more water than the 5-inch builder standard and pairs with larger 3x4 downspouts. In the Midlands, where summer thunderstorms drop an inch of rain in minutes, that capacity is the difference between draining and overflowing at inside corners and valleys.
The capacity math, in plain terms
Gutter capacity is not just width. A 6-inch K-style trough is wider and deeper, and the outlets fit 3x4 downspouts instead of 2x3. Together that moves far more water per minute. Roof pitch matters too: a steep roof throws water past the front lip of a small gutter in heavy rain, and the wider trough catches it.
Where 5-inch fails around here
- Inside corners where two roof planes dump into one short run. The most common overflow call we get in Lexington and Chapin subdivisions.
- Valleys that concentrate a whole roof section into one spot on the gutter.
- Long runs with one downspout, typical of builder installs that put in the minimum.
- Metal roofs on shops and rural homes, which shed water faster than shingles.
When 5-inch is still fine
Small, simple roofs with short runs and a downspout at each end, or matching an existing 5-inch system on one side of a house where the rest is sound. We will tell you at the estimate if 5-inch is genuinely enough; upsizing just to upsell is not how we work.
Downspouts matter as much as the gutter
A 6-inch gutter with too few downspouts still overflows. We place a downspout at every inside corner and size the run so no downspout is asked to drain more roof than it can. On Midlands clay, where the water goes after it leaves the downspout is the next problem, which is covered on our downspouts and drainage page.