I was surprised to learn that that there are risks with insulating the interior walls in older all-brick houses - particularly in cold climates. This article outlines some of the issues:


To summarize, the risks are:

  • Wooden joists sitting on (the now colder) brick will be wet from moist air condensing on the brick and the ends can rot

  • The inner layer (wythe) of brick will not be able to dry inwards. If the brick remains wet, it could fail (especially with freeze/thaw cycles)

These issues sound reasonable - however, articles refer to insulation in all-or-nothing terms. I'm wondering if there is some middle ground, to add some insulation to save some energy and increase comfort, without much risk of damaging the brick?

  • Could a vapour barrier be omitted, to allow for the brick to dry inwards?

  • Can a reduced level of insulation be used so the brick will still be warmed by the heat of the house?

  • Can walls have gaps in the insulation? e.g. leaving 12 inches at the top to warm the brick and help keep the joist ends dry?

  • Would techniques recommend for basement insulation be applicable? (e.g. use EPS or XPS board)

Any other safer options for interior insulation in an all-brick house?

  • I have found that just a small airgap behind basement walls do as much good as adding insulation because there is no air movement. As far as the block failing because of freeze thaw cycles I have never seen that happen.
    – Ed Beal
    Feb 10, 2017 at 14:38

1 Answer 1


A thermal resistant coating from outside may help to insulate the surface further more.

  • Exterior insulation is not an option. Feb 14, 2017 at 13:59

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.