Replies

1. 
   James Morgan|Feb 24, 2012 06:51pm|#1

   The deterioration you are concerned about is called spalling, which happens when water absorbed by the brick expands due to freezing temperatures. Without the moisture in the brick, no damage of this kind can occur. If your home has survived for over a century without this kind of problem it's likely that

   a) the original builders used a high quality non-absorbent brick called a facing brick on the exterior wythe, or

   b) the walls are reasonably well protected against saturation by roof overhangs, or

   c) both of the above.

   Bear in mind that for much of its life your home may have been heated sporadically and unevenly and the brick has already experienced as much freezing and thawing in unheated conditions as it ever will, even after you add insulation. Go ahead and properly insulate your home.

2. GBA Editor
   Martin Holladay|Feb 24, 2012 07:12pm|#2

   James,
   Your advice is overly broad. It certainly does not apply in Minnesota.

   I stand by the advice I gave in the earlier article,Insulating Old Brick Buildings. Insulating an older brick building in a cold climate changes the moisture content of the bricks, and therefore changes the bricks' susceptibility to freeze/thaw damage.

3. 
   Kristina Beedle|Feb 24, 2012 07:29pm|#3

   Thanks Martin. I have supplied your article and the content contained into the city along with my appeal. I have an appeal hearing on Tuesday, and I am hoping to convince them that if they make us insulate then they NEED to take responsibility when the brick fails, as I am pretty confident that it will. Our interior chimney that runs through the attic area has been rebulit and is still falling apart, which leads me to believe that some definite freezing & thawing has impacted that un-heated space.

   I am standing firm that we do not want to risk the implications that could result from putting the insulation in. We will air seal anything that we can, and will insulate the ceiling between the 2nd floor and the attic, but I do not want to insulate the home's brick walls and risk the brick failing.

4. 
   TJ Elder|Feb 24, 2012 08:00pm|#4

   Kristina, is there any chance you could insulate the exterior? This could give you both effective insulation and brick walls that should last another few centuries.

5. 
   Kristina Beedle|2012年2月24日08:04pm|#5

   TJ, at this time we would rather not do the exterior. I really like the look of the brick and don't want to compromise it. It may be something we can do in the future, but I just don't think it is necessary. We are already investing over 70K into this project, so we are trying to avoid any extra expenses. And the home is huge, so the exterior insulation would be a huge expense, and we would probably never re coup the cost.

6. 
   James Morgan|Feb 25, 2012 06:19am|#6

   Martin, I stand corrected. My comment was indeed unduly broad and clearly, changing the hygrothermal profile of a solid brick wall in a severe climate by adding interior insulation should be approached with caution. However, as many of the authorities referenced in your article emphasize, exterior water management is key, and poorly detailed buildings will exhibit damage whatever their insulation condition. Relying on heating the wall in order to dry it out seems like a poor solution.

   By the way, in the first of the photographs illustrating your article the extremely localized nature of the damage suggests that insulation is not the root of the problem. I'd suspect chronic, sustained water entry into the interior of the wall at a poorly designed and/or maintained window sill directly above the affected area being redirected to the face brick by an interior flashing at the header, or perhaps by the header itself.

   在接下来的照片太我问为什么those particular bricks had been affected. Is this a traditional load-bearing brick wall? Both the brick itself and the flush detailing of the arch seem rather modern and I wonder if this is brick infill to a steel or concrete frame building. Is that a weep hole in the center of the discolored area? Does the irregular mortar joint at the base of the affected area indicate an embedded flashing or steel angle? The caption says this problem manifested a couple of years after interior insulation, but as we all know, correlation is not necessarily causation.

7. GBA Editor
   Martin Holladay|Feb 25, 2012 06:41am|#7

   James,
   Your points are all addressed in my article. The experts all agree: if you intend to insulate an old building with multi-wythe brick walls, the first step is to address exterior water management issues.

   Once all of those water management issues are addressed, many (but not all) cold-climate brick buildings can be insulated on the interior. However, some brick walls receive too much rainfall, and have bricks of such a low quality, that interior insulation is not recommended.

8. 
   James Morgan|Feb 25, 2012 07:35am|#8

   Your points are all addressed in my article.

   Martin - yes indeed, I was referring to your article to emphasize that it's not the insulation nor the fact that the wall may be colder that's the problem, it's the presence of bulk water in the brick. And I have to question whether the absence of insulation would have been sufficient to avert the problems illustrated by the photographs in the article.

   As a further thought I'd be interested to know if modern brick veneers suffer from this type of damage in severe climates. The presence of a drainage plane between the brick and the framed wall will obviously be a positive drying factor, on the other hand the veneer is thin, quicker to freeze and almost entirely insulated from interior heat. Nor can we assume better installation, detailing, or brick quality in modern practice - drainage planes are only as good as their workmanship. It would seem puzzling if this were a concern only with older load-bearing solid brick walls.