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:
http://www.greenbuildingadvisor.com/blogs/dept/musings/insulating-old-brick-buildings
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?
