its not only the material, but what condenses on the roof over time, smog and other chemicals, bird poop,insects,molds.ect...

Hey Thanks. I understand that, but with all things been equal, what kind of roofing material is less toxic for such application. Cheers

g'day adolfo,

unless there is specific testing information available i realy can't see any probelms from the more common roof materials ie.,. metal either zyncalum or colour bonded or tiles/shingles as the rain isn't involved in prolonged contact with the roof for the main part.

also bird/frog or any other droppings on the roof are of very little concern to me we are still alive and kicking after 4 years so far of drinking rain water unfiltered (and spent most of my childhood doing the same never got sick). more to the point is what sort of material are you going to store your rain water in? we use poly tanks food grade made from local ingredients. but at the end of the day most storage systems are likley to or can leach into the water.

the main real concern as we see it is like the other poster said the chemical fall outs that land on your roof, if you are going to get serious about using rain water for drinking then you realy need to take into account your trade winds and what they blow over before they get to you take into consideration the following major highways or arterial roads, industrial centres airports etc.,. etc.,.

your tank water may only ever be fit for the garden and i know people in our capitol city who can't even collect it for the gardens as the fall out on their roofs is too toxic, just how it is and i could well imagine that this situation could be wider spread in the US of A.

len

mail len

lens garden page

Thanks mate,

I, too, have used unfiltered rainwater in the past without illness. I spent time in Indonesia and Turks and Caicos where rainwater was collected in concrete cisterns. I'm more worried about chemicals than the old Bali belly ;)))

Thanks for your input.

Adolfo

just as an aside adolfo,

i might have doubts about collecting rain from copper or lead based roofs.

len

hi Adolfo,
I was just down in Brasil living in ecovillage, where all their drinking water was rainwater. They have tiled roofs, which work beautifully! Their catchment system also has a tube that is filled up with the first 20 minutes of rain (which has bird poop and leaves and debris from cleaning the roofs), and then once that tube is filled, the clean water is caught in their tanks. As far as acid rain goes, if you put limestone in the bottom the tank, it neutralizes the water. I don't know about other chemicals though. The soft, green, living film that builds up around the inside of the tanks (which are covered) helps to filter the water, and as Bill Mollison told me (YES! I met Bill Mollison!) the film in his tanks "could eat a cat". hahaha. The debris that is caught in that first "filter" tube is then emptied and put in the compost. Hope this helps a little!
Lunaflora

Taino - do what your budget will allow, and don't stress it. Asphalt seems gross to drink off, but consider that the water doesn't spend much time up there. As Luna suggests, you might want to increase the size of your first wash just because it will take a little more water to clean off the rougher surface. What will you use for storage/cistern? We use poly tanks, which seem to be the least expensive, though an underground cistern is my longer-term goal (for longevity).