Roof Gutter Requirements

In order to decide for yourself whether rain gutters are necessary for your home it is best to first weigh the facts.

Roof gutter requirements.

Once an architect has determined the kind of roof he intends to use he must give equal attention to the design of the roof drainage system. If gutters slope too severely they don t hold water and water could splash over the sides in heavy rain. The steeper a roof s pitch the more windblown rain it can collect. Plumbers must now amend their guttering installation practices to ensure that they are up to date with the new standards.

Roof drip edge flashing serves multiple functions on a building the foremost of which is to assist water in leaving the roof edge with minimum damage to other building components by directing the water off of the roof and into the gutter. Roof area the locale s rainfall intensity and gutter capacity determine how many square inches of downspout are needed. Gutter systems consist of two parts. This article describes several methods for determining the drainage capacity required to safely drain water off of building roofs whether from rainfall melting snow or a combination of those water sources.

Design of roof drainage systems roof drainage the roof is one of the most essential parts of a building as it protects occupants contents and interior of the structure from the elements. We describe online roof drainage requirements calculators pertinent plumbing standards a table approach to looking up roof drainage. 1 gutter channels that run horizontally along the roof edge to collect runoff and 2 the downspouts that carry the collected water down. If a rainwater harvesting system is installed properly design the drain to adequately manage the overflow and meet discharge distance requirements.

A square inch of downspout can drain 1 200 square feet of roof during a rain with an intensity of one inch per hour. Roof drainage requirements specifications. Size downspouts to fit the gutter. Doubling the number of downspouts halves the required capacity for each.

If gutters don t slope water gathers in them. The international code council icc is a non profit organization dedicated to developing model codes and standards used in the design build and compliance process. They are generally not required by law on a sloping roof and many modern homes omit them even in instances where they are beneficial. What does it mean for installers.

You can measure pitch with a 2 foot level and a tape measure. The amount of collected water increases until it spills over the sides of the gutter. The gutter slope also called the pitch is the amount the gutter tilts down to let rainwater flow out of it. Hold one end of the level against the roof level it and then measure the distance between the roof and the underside of the level at its midpoint which gives you a 12 inch run.