Every Drop Counts: Rainwater Collection from Roofs

When April showers come this Spring, don’t waste them. Homeowners with certain kinds of roofing can resourcefully save their rainwater and use it for watering plants and gardens … or even to wash cars.

“Water harvesting is an easy, positive way to help the environment,” says Tim Gentry, vice president of technical services at DaVinci Roofscapes®. “Rainwater sliding off a polymer, metal, ceramic or real slate sloping roof into collection barrels is safe for secondary uses like garden irrigation. Roofs like these do not tend to leach chemicals or pollution into the water.”

Raindrops Add Up

Why should homeowners take steps to harvest rainwater? Along with helping save on water bills, rainwater collection is good for the environment. It can help reduce demands on shrinking ground water supplies.

“Whether collected in barrels or through pipes going directly into cisterns for use and storage, gathered rainwater can make a big impact,” says Gentry. “According to RainBarrelGuide.com, for every inch of rain that falls on a ‘catchment area’ of 1,000 square feet, approximately 600 gallons of rainwater can be collected. That’s quite a strong contribution to the water supply for a homeowner.”

Barrels of Rainwater

At the Absolute Green Home in South Salem, N.Y. (which won the “Best Renovation of the Year Award” in 2015 from Green Builder® Media), when it comes to rainwater collection, the owners have their neighbors over a barrel. Literally.

There are four rain water collection barrels dangling from key roof slopes on the renovated home. Each barrel encourages water to slide gently into it from the Bellaforté Slate polymer roof overhead via a chain. Once filled, the unfiltered water in the barrels can be used for exterior watering of plants and gardens.

This rainwater collection system was just one of many strategies that Sylvain Coté, project architect and coordinator with Absolute Green Homes, Inc., incorporated into the home. Starting from the top down with a composite slate roof, the 1932 beach home has earned three green designations: ENERGY STAR® Certified Home, LEED Platinum Certified Home and Home Energy Rating System (HERS) Certified Home.


Expansive Rain Harvesting Effort

In Narragansett, R.I., the Hageman family had a goal of reducing landscaping irrigation demand by at least 50 percent when they constructed their 5,300-square-foot Green Life Smart LifeTM home in 2009. They installed composite slate tiles from DaVinci Roofscapes to help them reach their goal.

“One of the key reasons we selected our DaVinci synthetic slate roof was because the tiles do not release toxins which could potentially run off into the water system,” says Hageman. “The rainwater collected from the roof over our home travels to an interconnected gutter system that directs all the water to our 5,000-gallon underground storage tank. We use the pure water as needed to support our landscaping efforts.”

Synthetic roofing tiles from DaVinci have inorganic pigments permanently bound into the polymer tiles, and meet Proposition 65 protocols. This California test (The Safe Drinking Water and Toxic Enforcement Act of 1986) certifies that products do not release or discharge toxins into water.