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

Insulating balloon framed house

Bryan_K | Posted in Energy Efficiency and Durability on

Hi All,

This is a followup to a previous post.

I’m about to purchase a balloon framed house and am going to add insulation. The current plan, depending on your guidance, is to insulate the box sill and the attic floor. This would, for the most part, stop the convection drying process in the wall cavities. I’d air seal the interior as well as possible.

Am I creating an environment for mold growth? If this would create an environment. Would a small space, maybe 1″x1″, without insulation at the top of each wall cavity allow for enough ventilation to dry out the walls?

Would the air leakage through the siding be enough to dry out the wall? 

The siding is clapboard. I think there is sheathing. It was built in 1947. 

Thanks in advance!

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. GBA Editor
    Brian Pontolilo | | #1

    Hi Bryan,

    Will you post a link to your previous post please?

    The best way to prevent mold growth is to keep water out of your walls. This starts with preventing rain and snowmelt from leaking into the house from the exterior. It also includes preventing condensation from occurring within the walls, by keeping air out and managing vapor drive the best you can. Finally, it is important to know how your walls will dry if they do get wet.

    I don't think that expecting uncertain air leakage to provide drying is a wise strategy. In fact, it could cause more harm than good as a lot of moisture rides on air. Water management and air sealing are your best tools here.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |