Functional Gutter System
Gutters drain water well away from the foundation — OR site has well-draining sandy soils verified per USDA classification.
Spec
Applies uniformly from Certified upward.
Scope
Roof drainage system — gutters, downspouts, splash blocks, and the ground area where roof water terminates.
Requirements
Choose one path
- 01.
Standard path: install gutters that fully capture roof runoff, with downspouts that discharge a minimum of 4 feet from the foundation (extended via splash blocks, underground drains, or extensions).
- 02.
Soil exemption: site has well-draining sandy soils (USDA classification: sand, loamy sand, sandy loam) verified by a soil test or USDA Web Soil Survey lookup. In this case gutters are optional.
Documentation
Evidence the inspector / Institute will need.
- 01.
Photos of installed gutters + downspouts + termination points.
- 02.
OR (soil exemption): USDA Web Soil Survey report for the project parcel showing eligible sandy soil classification.
Guidance
Why downspout extensions matter so much
A 1-inch rainfall on a 2000 sf roof produces 1,200 gallons of water. If that volume drops within 1 foot of the foundation, it saturates the soil there, raises hydrostatic pressure on the foundation wall, and over years pushes water into the basement. 4-foot downspout extensions are the single cheapest fix for basement leaks — $5-$30 per downspout.
Resources
- USDA Web Soil Survey →
Free lookup of soil characteristics for any U.S. parcel.
Note
In tight urban sites where 4-foot extensions aren't feasible, underground PVC drain to a daylight termination or dry well is acceptable. Sump pump discharge does not count — that's water already inside the building.