Vapor Retarder for Basement Walls
Hello, I’m in zone 5 upstate NY. I do get water on the inside of my block foundation interior basement walls after heavy rains which is directed to my whole basement perimeter drain system (plastic tray impeded in concrete, directed to a sump pump). Short of excavating outside of the basement wall, can I stop vapor intrusion and direct water into my drain system with a vapor barrier? Ive seen a few sources, Martin Holladay being one of them, saying you can’t use polyethylene against basement wall but you can use a vapor impermeable insulation (rigid foam board, closed cell spray foam) on the inside of basement walls. I don’t understand why there is a difference besides the ability for moisture to condense on a cold wall with a vapor barrier- but isn’t the basement wall damp anyway? I obviously don’t want to encourage a mold growth situation.
I was hoping to stop vapor permeance as a first step and maybe eventually insulate.
Thanks for your help!
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