Q/A #132 - Is Rainwater Collected from a Roof OK to Use?

QUESTION:
If I collect rainwater that has run over my asphalt shingle roof, will it harm my carnivorous plants? Are there any chemicals in the shingles that will leech into the rainwater and harm my plants?
(Submitted in July 2021.)

RESPONSE BY JEFF DALLAS:
It's fine to collect from a composition roof. Any substances that might have been there would only be present in harmful quantities briefly when the roofing material was new. After many rain storms all that would have been leached out.

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