I had an inquiry about using roofing material as a pond liner. I looked it up online and found the following from a manufacturer of roofing material. I guess we can't get a better answer than this:
There is a difference in Pond Liner EPDM and roof grade EPDM.
Most roof grade EPDM is chemically compounded to be specifically used in roofing installations. Part of the mixing and compounding process usually includes the use of additives such as anti bacterial and anti fungicide agents that will prevent mold, mildew, fungus and other such growths from happening on a roof top. These are additives that the pondkeeper would prefer NOT to have in their pond liner, particularly in order to maintain the health and proper balance of the pond life.
EPDM Pond liners are proven fish friendly, and is a membrane which has no anti bacterial or anti fungicide additives used in the manufacturing process. In addition EPDM Pond Liners are practically talc FREE. Thus providing an enhanced performance of the sheet as a 100% secure and healthy habitat for all of your pond life.
If you are a roofing contractor and use roofing EPDM, then buy Roof Grade EPDM with all of the additives. If you need Pond Liner EPDM and would like to maintain a healthy pond environment, then buy an EPDM Pond Liner!
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