The consensus on the internet about the safest roofing material for rainwater collection is there is no consensus.
Roof material for rainwater harvesting.
For the vast majority of tank based rainwater harvesting systems the catchment area is the roof surface.
Asphalt shingles are usually treated with moss killing chemical which can pollute collected water due to its copper and zinc content.
Tin tin is one of the best rainwater harvesting roof materials to have on a project.
There is very little water loss with tin around 5 and no worries of contaminants leaching out from the tin with an approved nsf 61 coating.
Finally plan on discarding the first few gallons of rainfall at the beginning of a rain and then purifying your harvested rainwater in some basic way before you drink it.
This means that care needs to be taken by those who have such roofs installed and would like to be able to drink water harvested from them.
There are some important factors about the roof to consider when planning for a rwh system.
The good news is most roofing materials are suitable for rainwater harvesting.
Read down the list for info on roofing materials for rainwater harvesting.
Use rubber galvanized metal or aluminum for flashing and vent seals and stay away from lead.
Specifically this is set up for my rainwater garden area but c.
And chemical contaminants but even after the first flush water contained more turbidity total coliform fecal coliform iron and aluminum than is recommended by the epa for drinking water.
Rainwater from asphalt fiberglass shingle roofs was found to be high in doc but perhaps surprisingly so too were green roofs.
While metal roofing or plastic sheeting e g.
Building a rain roof as another option to harvest rainwater for home garden or livestock use.
Unfortunately as shingles age the concentration of pollutants such as zinc iron and particulate matter in water increases.
Roof material the material of the roof is not as important as contaminants that may be on the roof.
Asphalt shingles are the most common material used on roofs and luckily they are also a very good option when it comes to rainwater harvesting.
A recent report from the texas water development board entitled.
Effect of roof material on water quality for rainwater harvesting systems looked at the effect that different roof treatments have on the water quality of collected rainwater.
One of the main reasons is their uneven surface it makes it harder for soot and other pollutants and dirt to gather on top of it.
Greenhouse roof has the highest collection efficiency most surfaces are a ok.
Asphalt shingles many shingles work with rainwater harvesting.
Materials studied included asphalt fiberglass shingles galvalume metal panels and concrete tiles.
For landscape purposes the common asphalt shingle will work fine.