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

Insulation retrofit with added sheathing, rigid foam insulation, and rain screen – and orignal wood windows

FarmhouseRob | Posted in General Questions on

First, Green Building Advisor has been a godsend to this newbie energy retrofit on an old house.  Thanks to Martin and the crew for all the great resources, especially the series,

My 1899 farmhouse (Climate Zone 4/5) is being resided so I plan to add some energy benefits in the process.  The original walls are beadboard wall paneling, 2×4 studs, and siding. The siding will be removed. I plan to add Rockwool batts in the stud cavities, add a sheathing and WRB, and rain screen and then new wood siding.

1) I’m leaning toward Zip-R3 for the combination sheathing and rigid foam insulation. I’m worried about long-term survivability of the taping. Should I consider having it installed with using the liquid flashing over the seams and holes as I’ve heard recommended? Should I be concerned about the use of Zip or Zip-R3 on the remodel won’t work as well as new construction? Is there a better benefit to using plywood sheathing, WRB, and then rigid foam insulation? 

2) Besides adding to the energy gains, I’m also wanting to maintain the historic nature of the building. The large (5′ x 2′) windows are beautiful and a great feature. They need work but are generally in great shape. I’ve read about ways to weatherstrip, insulate window pockets, and use of blinds and storms; however, I can’t find much information about how to better seal and flash the windows while I have the siding off.  I plan to add trim to keep the window exterior profile the same but I’m hoping to improve on their performance while I’m at it. Tips, tricks, suggestions?

Thanks everyone for your assistance with my project. 


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. Expert Member
    BILL WICHERS | | #1

    You probably want at least R5 worth of exterior foam depending on exactly where you are climate zone wise. R3 is a bit light. Zip tape used with Zip sheathing has a good reputation for working well, and is used all the time, but BE SURE to ROLL the tape! This is an important step to make sure the tape adheres properly. You also want a clean and dry surface, so don't tape in the rain, etc.


Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |