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 victorian house walls

mcbane | Posted in Energy Efficiency and Durability on

I have a house built in 1868.  The exterior walls are lapped redwood siding, full dimension 2×4, and then lathe and plaster on the interior.  There is no moisture barrier under the siding.

A contractor has proposed renailing (old square nails badly corroded), caulking and painting the siding and then using fiberglass insulation on the wall interior.  The lathe and plaster would be replaced with plywood for shear strength, covered by sheet rock.

My concern is that moisture will inevitably get inside the wall and then be soaked up and retained by the insulation, leading to long term wood rot or mildew problems. 

Would use of rock wool instead of fiberglass insulation reduce the risk of moisture damage?  Is there any other detail I should be asking for to prevent moisture problems in the walls?


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
    Michael Maines | | #1

    Nicolas, Martin covered this topic thoroughly here: If you don't have GBA Prime, it's worth the price, but you can also do a trial subscription if you don't want to commit.

  2. mcbane | | #2

    thanks. Just what I was looking for.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |