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

Sealing bottom of exterior roof wool insulation

Salesi| Posted inGeneral Questionson

We will be installing 2″ of rock wool insulation on the exterior of our new house with a 3/4″ rain screen. How would the bottom of the rock wool be sealed from insects, etc. since it is only semi rigid? Should I run a 1 x material cut to 2″ wide around the piermeter of the house and set the rock wool on top of this? Or get a J shaped piece of flashing to set the rock wool into? I do not want to just leave it open. 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. Expert Member
    Akos||#1

    Get perforated J channel bent up that is 2 3/4" wide. This would cover the bottom of the rigid as well as the rain screen gap and keep all insects out of both.

  2. Salesi||#2

    Thanks for the reply. Is this available or something I would have to have fabricated specifically for my job?

    1. Expert Member
      Malcolm Taylor||#3

      Salesi,

      Because that's wider than the typical J channel used on rain-screens, you are probably best to get it custom-bent locally, although you could have to shipped from Menzies:
      https://www.menzies-metal.com/vent-flashings/perforated-j-channel-rain-screen-low-back/

  3. Expert Member
    Zephyr7||#4

    HVAC contractors that make their own ductwork (that includes most of the commercial shops) can usually fabricate this for you. They can get perforated galvanized sheet, although stainless is better (and more expensive). Any sheet metal shop with a brake and a shear can form the stuff.

    Bill

Log in or create an account to post an answer.

Community

Recent Questions and Replies

  • |
  • |
  • |
  • |