Collecting rainwater is a great way to live sustainably. It can be challenging, however: materials, building, and upkeep is a lot of work. But don’t worry! Alamance Insulation and Gutters is here to help! Alamance Insulation and Gutters is a leader in the insulation and home performance industries. Serving customers throughout North Carolina, from Greensboro, Burlington, Elon and Mebane to Chapel Hill, Durham, and Raleigh, we can help with all your insulation and gutter needs.

Having the right roof for rain harvesting is imperative. There are four types of roofs you can have for collecting rain. 

Standing Seam Metal

If you’re installing a new roof for the purpose of collecting rainwater, standing seam metal may very well be your best choice. A high quality enameled roofing material that is easy to clean, standing seam metal offers the highest collection efficiency available.

The American Rainwater Catchment Systems Association (ARCSA) advises that “standing seam roofs, powder coated or enameled, Galvalume (zinc + aluminum alloy) with non-toxic baked or enamel finish are appropriate for potable use with non-toxic finishes and appropriate components, tanks, and post-tank treatment.”

Corrugated Metal

Corrugated metal also makes an efficient collection surface, but there is a precaution:

Most corrugated material is galvanized, which will leach some zinc into the rainwater. Many people collect from galvanized roofs with no problem, but this is something to be aware of. Collect a sample of rainwater and use a home test kit or send it to a lab to make sure zinc levels are below allowable limits for drinking water. Zinc is an herbicide, so even if you won’t be drinking the water, you’ll want zinc levels to meet that standard to avoid hurting your plants.

Asphalt / Bitumen / Composition Shingle

Asphalt is the most common type of roofing. It is inert, and generally safe for rainwater collection. That said, the adhesives used for installation are worth a mention. These adhesives do most of their off-gassing within a year of installation, and virtually all of it within three years, so if you have a brand new asphalt shingle roof (also known as composition shingle), you may wish to avoid irrigating edibles for the first three years. Are you going to be drinking the water? All potable systems must include treatment anyway, but send a sample to the lab to see what you need to treat for.

Concrete or Clay Tile Roofs

Clay and concrete tiles have lower collection efficiency than other roofing materials, simply because the tiles are porous and absorb so much water. This doesn’t mean you can’t harvest off them, though. With over 600 gallons of high quality water available from a single inch of rain falling on 1000-square-foot surface, even an 85% collection efficiency (estimated for clay tile) will give you a lot of high quality water. Concrete tile may leave you with alkalinity in your water, but this isn’t necessarily a problem. A simple home test kit will allow you to measure your pH.

So if you’re thinking of harvesting rainwater, let us help! If you have questions about gutters or you would like to rely on professionals to do the job for you, call Alamance Insulation and Gutters. We service many areas in North Carolina, including but not limited to Burlington, Greensboro, Elon, Mebane, Chapel Hill, Durham, and Raleigh. We’re happy to help with all your insulation and gutter needs!