GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Floor installation

Toole311 | Posted in General Questions on

Hello  i have built a cabin about 2 years ago.  ( knowing then alot less then i know now )  and just in general i am wondering if what i have done will be sufficiant for the long haul. 

Basically i have a raised floor on pier and beams . The layers of the floor go as such from outside ( bottom) to inside ( top)

-2″ foam board insulation with gaps around edges sprayfoamed 

-r20 rockwool insulation in between floor joists

– layer of subfloor (1″×8″x 12′ pine boards) running E to W

– 6 mil poly barrier over entire floor inside ( but only to the egdes of the walls where its tied into the 6 mil on the interior walls )

– then a second layer of 1″x8″x12′ pine boards running N to S. Used as my interior flooring .

I cant help but think something may have been done wrong here  any help  or suggestions will be appreciated.  

Thanks   alex

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.


  1. Steve Knapp CZ 3A Georgia | | #1


    Where is your cabin located? Is this a year-round home or just a getaway place? Do you have heat and AC systems?

  2. GBA Editor
    Brian Pontolilo | | #2

    Hi Alex.

    Assuming you hit appropriate R-values for your cabin's location, I think your floor will be fine. You didn't need the interior poly, and some will be concerned that you have a double vapor barrier problem. But if the assembly doesn't get wet, you don't have a problem.

    So, if the floor is well air sealed and rain isn't getting into the assembly, then it doesn't need to dry, and you'll be fine for the long haul.

    Have you seen this: Insulating a Wood-Framed Floor Assembly

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |