https://www.pennplan.com/products/pennflat-eva-membrane.html
EVA Membrane
PENNFLAT EVA Membrane is a kind of flexible sheet material with excellent resistance to environmental stress cracking, good toughness, weather resistance, low-temperature resistance, especially suitable for the inner surface of vaults.
Features:
1. Resistant to chemical corrosion and ultraviolet radiation.
2. Convenient construction, no pollution.
3. Good aging resistance and corrosion resistance.
4. Strong puncture resistance.