GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter X 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

Leave exterior rock wool uncovered for a few weeks?

finePNW | Posted in General Questions on

Has anyone had experience leaving exterior rockwool uncovered during construction delays. There’s rain in the forecast and lows in the mid 40s, but I don’t think freeze thaw will come into play before we get siding up. I’m curious if folks have any thoughts on how long and under what conditions rock wool (comfortboard 80) can be exposed to the elements before being sided over?

I understand there is a technical bulletin on this, but it’s a bit vague in terms of how long it *can* be exposed.


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. Ryan_SLC | | #1

    It will dry out and retain 100% of it's performance.

    Simply hanging a tarp from your sub fascia to fully protect the OSB was offered by to me by my spray foam company as I wait for windows to arrive. Not a horrible idea depending on how much area you're talking about.

  2. user-5946022 | | #2

    It will be fine.
    Rockwool stays "exposed" (partially) forever on some commercial buildings that get exterior insulation + rain screen. Many commercial rainscreens are just decorative - just a screen, not a barrier. Wind & rain can get past and through them to the rockwool.

  3. finePNW | | #3

    Thanks all. Good stuff.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |