GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Audio Play Icon Headphones Icon Plus Icon Minus Icon Check Icon Print Icon Picture icon Single Arrow Icon Double Arrow Icon Hamburger Icon TV Icon Close Icon Sorted 汉堡/搜索图标

Community and Q&A

Polyiso for basement floor?

James Fugate| Posted inGeneral Questionson

I have an unfinished basement with essentially a dirt floor (with a thin layer of crumbly cement) and a rubble foundation. I’d like to dry the basement by installing 6 mil sheeting on top of the floor and up the basement wall to the sill beam. I have a stack of 3” reclaimed polyiso insulation left over from a roofing job. Can I lay the polyiso on the basement floor on the sheeting and then cover ut with 1/2” plywood?

The basement is only used for storage. I know polyiso can not be used for ground contact, but can I use it on the basement floor Over a vapor barrier and be walked on? Thanks.

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.

Replies

  1. GBA Editor
    Martin Holladay||#1

    James,
    EPS would be a better choice for this application -- because crawlspace floors can be damp, and it's possible for water to puddle on top of your polyethylene in some circumstances. Polyiso can absorb water more readily than EPS.

    All of that said, if you know that your crawlspace floor is dry and puddle-free, and if the polyiso is free -- using it makes environmental sense and economic sense.

Log in or create an account to post an answer.

Community

Recent Questions and Replies

  • |
  • |
  • |
  • |