Thread: Insulating Brick Veneer Homes (with 2"x4" wood framing)

I think I may have just made a huge mistake, and I need a more definitive answer than I can find on the Internet.

I presently live in a brick veneer home that was built in 1960. The brick is built approximately 1/2 inch to 3/4 inch from the wood frame of the house, which consists of standard 2 X 4 construction (depths of wall 3.5 inches). On the complete western side of the house, I just completed a retrofit where I did the following just months ago: (1) I removed all the sheetrock (2 foot width boards) and plaster. This exposed an interior that had no insulation. I could see the exterior sheathing which consisted of some type of dark, perhaps petroleum-based, wafer board about 3/4 inch thick. (2) I then used Owens-Corning fiberglass batts (pink) with facing and applied this to the 2 X 4 studding. I took my time doing this. (3) I then installed a 6-mil plastic vapor barrier on top of this faced insulation. (4) I then installed 7/16" oriented strand board next. (5) I then installed 1" of your Owens-Corning poly pink board on top of the OSB. (6) I then installed 1/2" of sheetrock on top of the pink board. Summary: Brick, a small air gap, dark waferboard, pink fiberglass insulation with facing, 6-mil vapor barrier, OSB, pink poly insulation sheets, sheetrock, and then paint.

After doing all of this, I was speaking to a mason and was horrified that I might have done something I shouldn't have. I also did quite a bit of research and have found data to be very sparse about renovating brick veneer homes with insulation. The mason seemed to think that I might have subjected the brick facade to potential damage and the interior insulation batts to moisture.

Please help me before there may occur any permanent damage to my home. Is there any documentation about insulating wood framed homes with a brick veneer? I need to know if I should go in there and take all of that out. I had thought about applying a brick sealant in the spring and retrofitting weep holes at the bottom of the brick. (I don't think there are any.) There seemed to be good air circulation when I was putting in the insulation and I would run my hand near the holes where the masons would put their level lines. I mean, these holes were in the wafer board and I could feel a positive air flow. I don't remember if it was coming in or going out, though.

Please help me. Anything you can provide would be appreciated.

Thanks

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Read this then ask yourself if you created a moisture trap.
Vapour Barriers ... when and where to use them

Not the way it is usually done, but I don't see any reason why it wouldn't work.

The damage in the shower in Bob's link is most likely from water leakage through the tile and not from vapor diffusion.

The rule of thumb is that the vapor barrier should be no more than 1/3 of the way (in terms of R-value) into the wall.

I would not apply a sealant to the brick.

Originally Posted by David Wood

Not the way it is usually done, but I don't see any reason why it wouldn't work.

The damage in the shower in Bob's link is most likely from water leakage through the tile and not from vapor diffusion.

The rule of thumb is that the vapor barrier should be no more than 1/3 of the way (in terms of R-value) into the wall.

I would not apply a sealant to the brick.

I should have said the link was for a wall tile site but the explanation of trapped moisture holds true so I added the link as something to think about.
Not being there we can not really do much other than give educational guesses though the thought of moisture becoming trapped between the foam and sheeting at inside of the drywall may cause mold to grow on the insulation.
The mention of black wafer board already has me thinking mold.

Thanks, Bob, for your site. It is sort of neat how the Brits and Australians sometimes have the same types of problems we have. I took into consideration that this was mostly for tile applications in what looked like rooms that would have "high humidity." The rooms I renovated were one wall in the living room and two bedrooms. I don't envision condensation where I have placed my vapor barrier in this instance.

What does concern me is the "vapor diffusion" as discussed by David. Actually, there are two concerns. Because of the porosity of the brick and mortar, I am first concerned that vapor diffusion will transit the air gap between the brick and waferboard and continue into the insulation batts that I installed in between the studs. Do I truly need to be concerned about water vapor getting trapped in insulation batts that would be on the cold side of a vapor barrier?

My second concern is that by insulating the framing of the house, I have caused the brick veneer to be colder in the winter than in the past. With vapor diffusion, wicking, etc., do I need to be concerned about spaulding, cracking, etc., just a general degredation of the brick veneer because the home is insulated and I have shifted the freeze-thaw line more into the brick veneer.

By the way, the brick veneer is just your standard one tier of brick. It isn't doubled.

Originally Posted by Harry Turner

Thanks, Bob, for your site. It is sort of neat how the Brits and Australians sometimes have the same types of problems we have. I took into consideration that this was mostly for tile applications in what looked like rooms that would have "high humidity." The rooms I renovated were one wall in the living room and two bedrooms. I don't envision condensation where I have placed my vapor barrier in this instance.

What does concern me is the "vapor diffusion" as discussed by David. Actually, there are two concerns. Because of the porosity of the brick and mortar, I am first concerned that vapor diffusion will transit the air gap between the brick and waferboard and continue into the insulation batts that I installed in between the studs. Do I truly need to be concerned about water vapor getting trapped in insulation batts that would be on the cold side of a vapor barrier?

My second concern is that by insulating the framing of the house, I have caused the brick veneer to be colder in the winter than in the past. With vapor diffusion, wicking, etc., do I need to be concerned about spaulding, cracking, etc., just a general degredation of the brick veneer because the home is insulated and I have shifted the freeze-thaw line more into the brick veneer.

By the way, the brick veneer is just your standard one tier of brick. It isn't doubled.

Well I guess it shows the laws of physics stay the same though they have backwards swirl of toilet water.
The thing is that in winter all your heat is trying to escape the home and with it humidity as winter is dryer.
Also there is no perfect water barrier which is a lot to consider.
We have a Inspector in Chicago that actually gives courses on Brick Veneer and water Intrusion issues as they are a big problem around here due to all the CMU and split block construction we had here during the last building boom.Will Decker.Here is a link to one of his articles Split Faced Block builings problems update.| Decker Home Inspection Services.

Your post sure has me thinking about the insulation install in Brick Veneer right now.

Originally Posted by Harry Turner

Thanks, Bob, for your site. It is sort of neat how the Brits and Australians sometimes have the same types of problems we have. I took into consideration that this was mostly for tile applications in what looked like rooms that would have "high humidity." The rooms I renovated were one wall in the living room and two bedrooms. I don't envision condensation where I have placed my vapor barrier in this instance.

What does concern me is the "vapor diffusion" as discussed by David. Actually, there are two concerns. Because of the porosity of the brick and mortar, I am first concerned that vapor diffusion will transit the air gap between the brick and waferboard and continue into the insulation batts that I installed in between the studs. Do I truly need to be concerned about water vapor getting trapped in insulation batts that would be on the cold side of a vapor barrier?

My second concern is that by insulating the framing of the house, I have caused the brick veneer to be colder in the winter than in the past. With vapor diffusion, wicking, etc., do I need to be concerned about spaulding, cracking, etc., just a general degredation of the brick veneer because the home is insulated and I have shifted the freeze-thaw line more into the brick veneer.

By the way, the brick veneer is just your standard one tier of brick. It isn't doubled.

Which way did you face the paper on the fiberglass insulation?

Originally Posted by Door Guy

Which way did you face the paper on the fiberglass insulation?

It is on the warm side of the house, closer to the interior than the exterior.

add

Originally Posted by Harry Turner

I think I may have just made a huge mistake, and I need a more definitive answer than I can find on the Internet.

I presently live in a brick veneer home that was built in 1960. The brick is built approximately 1/2 inch to 3/4 inch from the wood frame of the house, which consists of standard 2 X 4 construction (depths of wall 3.5 inches). On the complete western side of the house, I just completed a retrofit where I did the following just months ago: (1) I removed all the sheetrock (2 foot width boards) and plaster. This exposed an interior that had no insulation. I could see the exterior sheathing which consisted of some type of dark, perhaps petroleum-based, wafer board about 3/4 inch thick. (2) I then used Owens-Corning fiberglass batts (pink) with facing and applied this to the 2 X 4 studding. I took my time doing this. (3) I then installed a 6-mil plastic vapor barrier on top of this faced insulation. (4) I then installed 7/16" oriented strand board next. (5) I then installed 1" of your Owens-Corning poly pink board on top of the OSB. (6) I then installed 1/2" of sheetrock on top of the pink board. Summary: Brick, a small air gap, dark waferboard, pink fiberglass insulation with facing, 6-mil vapor barrier, OSB, pink poly insulation sheets, sheetrock, and then paint.

After doing all of this, I was speaking to a mason and was horrified that I might have done something I shouldn't have. I also did quite a bit of research and have found data to be very sparse about renovating brick veneer homes with insulation. The mason seemed to think that I might have subjected the brick facade to potential damage and the interior insulation batts to moisture.

Please help me before there may occur any permanent damage to my home. Is there any documentation about insulating wood framed homes with a brick veneer? I need to know if I should go in there and take all of that out. I had thought about applying a brick sealant in the spring and retrofitting weep holes at the bottom of the brick. (I don't think there are any.) There seemed to be good air circulation when I was putting in the insulation and I would run my hand near the holes where the masons would put their level lines. I mean, these holes were in the wafer board and I could feel a positive air flow. I don't remember if it was coming in or going out, though.

Please help me. Anything you can provide would be appreciated.

Thanks

IMO Harry I think its overkill. Sounds to me like your describing Buffalo Board for the exterior sheathing. The Brick veneer is not Structural, so no worrries there. I have an issue with the vapor barrier, the osb, and the 1" pink sheets than the dry wall. You may have humidity issues inside the house. Our houses need to breath, and to let moisture pass through the wall to the outside. Our basement walls breathe from the exterior into the interior. I'm in Canada and it's -25 to -35 degrees celcius on a regular basis. Here's how i've seen it. Brick, 1" air gap, felt paper, buffalo board, R12 insulation or better, limited to the 2x4's, 6mil vapor barrier, dry wall. The weight of all that mat'l you put up could cause some sort of structural issue in the long run, just a thought. Hope that helped a little

"There seemed to be good air circulation when I was putting in the insulation and I would run my hand near the holes where the masons would put their level lines. I mean, these holes were in the wafer board and I could feel a positive air flow. I don't remember if it was coming in or going out, though."

The black sheathing sounds like Homesote or Celotex sheathing, what concerns me is why is there holes from the sheathing into the brick air space if I under stand you correctly by the above quote. If there is a through wall flashing, drilling holes through existing brick veneer can be a delicate matter not to comprimise the flashing material.

Personally ,I am not a big fan of plastic over the paper face insulation with all this air tightness as for my neck of the woods anyway, what are your windows like.None of thats worth any thing if the windows are original or cheap vinyls were installed

I loved the Buffalo board slang, we used to call it Beaver Board

Originally Posted by Harry Turner

I think I may have just made a huge mistake, and I need a more definitive answer than I can find on the Internet.

I presently live in a brick veneer home that was built in 1960. The brick is built approximately 1/2 inch to 3/4 inch from the wood frame of the house, which consists of standard 2 X 4 construction (depths of wall 3.5 inches). On the complete western side of the house, I just completed a retrofit where I did the following just months ago: (1) I removed all the sheetrock (2 foot width boards) and plaster. This exposed an interior that had no insulation. I could see the exterior sheathing which consisted of some type of dark, perhaps petroleum-based, wafer board about 3/4 inch thick. (2) I then used Owens-Corning fiberglass batts (pink) with facing and applied this to the 2 X 4 studding. I took my time doing this. (3) I then installed a 6-mil plastic vapor barrier on top of this faced insulation. (4) I then installed 7/16" oriented strand board next. (5) I then installed 1" of your Owens-Corning poly pink board on top of the OSB. (6) I then installed 1/2" of sheetrock on top of the pink board. Summary: Brick, a small air gap, dark waferboard, pink fiberglass insulation with facing, 6-mil vapor barrier, OSB, pink poly insulation sheets, sheetrock, and then paint.

.....

Thanks

Harry,

I think you may have a Vapor Barrior (VB) issue. I am assuming your used the foil faced fiberglass insulation. I see a minimum of three vapor barriers with OSB between them.

(1) Brick Porris - Non VB
(2) Sheathing - Depending on material, Possibly a VB
(3) Fiberglass insulation with facing in toward heated area - VB
(4) 6-mill plastic sheeting - VB
(5) OSB - Non VB
(4) Pink Rigid Foam - VB
(5) Sheetrock - Non VB
(6) Paint - Some paints have a VB quality

I think that you may have too many VBs. Did you use the VB tape to seal the seams in the plastic and also the foam?

Rich

Here is some good info here:
Energy Savers: Vapor Barriers or Vapor Diffusion Retarders

Harry waking up I just realized the best place to ask this question for a conclusive answer is over at a site IN member Carl Brown belongs to.
Hate to recommend a forum on a forum but do yourself a favor and check this one out......National Association of Commercial Building Inspectors - Index
Sure can not hurt to add more opinions and thanks for asking this here as it helps me know I am weak in this area so will visit there myself when back from inspecting later.

Originally Posted by Harry Turner

What does concern me is the "vapor diffusion" as discussed by David. Actually, there are two concerns. Because of the porosity of the brick and mortar, I am first concerned that vapor diffusion will transit the air gap between the brick and waferboard and continue into the insulation batts that I installed in between the studs. Do I truly need to be concerned about water vapor getting trapped in insulation batts that would be on the cold side of a vapor barrier?

My second concern is that by insulating the framing of the house, I have caused the brick veneer to be colder in the winter than in the past. With vapor diffusion, wicking, etc., do I need to be concerned about spaulding, cracking, etc., just a general degredation of the brick veneer because the home is insulated and I have shifted the freeze-thaw line more into the brick veneer.

By the way, the brick veneer is just your standard one tier of brick. It isn't doubled.

Any vapor diffusion that you need to worry about is from inside. That is why, in a northern climate, the vapor barrier is on the inside. Again, I don't see a problem with your unconventional construction.

As far as the brick veneer goes, as long as it can dry (ie. no sealer on the outside) you should not have a problem with spalling. You are correct that now that the brick is not kept warm by the house it will experience more freeze/thaw cycles, which could cause spallling if the brick is wet.

Brick veneer is the predominant construction around here and it is rare to see brick spalling on low-rise buildings. (It is seen commonly on 6+ storey buildings that have strong stack effect driving air/moisture through the walls on the top storeys.)

"The black sheathing sounds like Homesote or Celotex sheathing, what concerns me is why is there holes from the sheathing into the brick air space if I under stand you correctly by the above quote. If there is a through wall flashing, drilling holes through existing brick veneer can be a delicate matter not to comprimise the flashing material.

Personally ,I am not a big fan of plastic over the paper face insulation with all this air tightness as for my neck of the woods anyway, what are your windows like.None of thats worth any thing if the windows are original or cheap vinyls were installed

I loved the Buffalo board slang, we used to call it Beaver Board."

-----

Thanks for your reply, Joe. I think you are correct on the Celotex. I remember now some of the print on the sides. Ummm, the holes I was referring to were when I was looking outward. It appeared to me that the masons had cut 4"x4" squares at each end of the room, a set at about two feet up from the floor, the other set about six feet up from the floor. In each instance, there was a bent over nail near the hole, so I assumed they were used to tie off their "mason twines." I went to the website for Celotex and see now their sheathing is more insulated, blue, and probably more a poly-based chemically extruded board. The 4'x8' boards on the exterior of the wood framing was darker, seemed to have a petroleum base, and was more like compressed sawdust with a tougher consistency.

The windows are good. Newly installed double-paned Jenkins. All potential entry/exit points in the wall, i.e., outlets, windows, were insulated and sealed. You bring up one point about moisture, and I consistently hear this in some of the other postings about allowing a house to breath. I have a Carrier HVAC system that has a built in dehumidifier, which I have set to about 20%. Indeed, the plastic vapor barrier doesn't seem to allow vapor diffusion as some would like, but I am confident my air handler unit is removing moisture/water vapor where it should. I have had no issues with peeling or bubbling paint which might indicate condensation or moisture issues below the sheetrock.

Thanks again...

Originally Posted by Rich Goeken

Harry,

I think you may have a Vapor Barrior (VB) issue. I am assuming your used the foil faced fiberglass insulation. I see a minimum of three vapor barriers with OSB between them.

(1) Brick Porris - Non VB
(2) Sheathing - Depending on material, Possibly a VB
(3) Fiberglass insulation with facing in toward heated area - VB
(4) 6-mill plastic sheeting - VB
(5) OSB - Non VB
(4) Pink Rigid Foam - VB
(5) Sheetrock - Non VB
(6) Paint - Some paints have a VB quality

I think that you may have too many VBs. Did you use the VB tape to seal the seams in the plastic and also the foam?

Rich

Thanks, Rich, I had this same concern before applying the pink rigid foam. I had emailed one of the engineers at Owens-Corning, and he provided that it would allow for vapor diffusion. So, I didn't really think of it as substantially acting as a vapor barrier.

I'm not a fan of plastic sheeting over the studs. You should have used unfaced insulation if you placed the plastic sheeting over it. I'm afraid that you might end up with a mini rain forest in that wall cavity. It might not show for a couple of years, it all depends on the environment.

Originally Posted by Scott Patterson

I'm not a fan of plastic sheeting over the studs. You should have used unfaced insulation if you placed the plastic sheeting over it. I'm afraid that you might end up with a mini rain forest in that wall cavity. It might not show for a couple of years, it all depends on the environment.

Would I have been just as well to have left the plastic vapor barrier off and let the facing act as a vapor barrier?

Originally Posted by Harry Turner

Would I have been just as well to have left the plastic vapor barrier off and let the facing act as a vapor barrier?

Kraft paper is really vapor retarder and plastic is a vapor barrier. That being said, to get a true vapor barrier there is more to it than just stapling up plastic. Proper treatment of outlets etc...

You could have left the plastic off and just used the kraft paper faced insulation as the vapor retarder.

I don't see anything bad happening to the brick, and depending on your climate and location of the house, you may not have a problem in the wall cavity either. Based on what was done, more than likely you will notice moisture on the floor that gets caught by the plastic and runs down instead of in the wall cavity. The object of the vapor barrier is to stop the interior moisture from entering the wall cavity and condensing in the insulation and wall cavity.

There are so many factors here, what works in one house is bad for another...

Is there any chance that the outside sheathing in his wall is a product that was called Homasote?
Though I am not sure that it makes much of a difference to this discussion, he certainly cannot make changes to that area due to the location under the brick. I have seen this product have real issues over time however, it was on a shed and not protected from the elements.

I may have missed it but at this point can we have pictures?

Originally Posted by Bob Elliott

I should have said the link was for a wall tile site but the explanation of trapped moisture holds true so I added the link as something to think about.
Not being there we can not really do much other than give educational guesses though the thought of moisture becoming trapped between the foam and sheeting at inside of the drywall may cause mold to grow on the insulation.
The mention of black wafer board already has me thinking mold.

The black wafer board he is referring to is obviously asphalt impregnated sheathing or black board. It is a cheap method of building in enclosing the structure and is allowable under most building codes. However, it does not provide a continuous load path for the building and is not allowable under most high wind conditions unless each stud is tied to the foundation plate. Several manufacturers have introduced foam panels that meet requirements for load path and add insulation values to the wall.

In my area, a poly vapour barrier is required on the innermost surface, directly behind the drywall. So there is no rule which fits every location.

Beaver board, blackcote, etc, is not prone to mold problems. The OSB is, it is a moisture sponge that turns black with mold before your eyes, especially with poly against the back side.

Originally Posted by Harry Turner

I think I may have just made a huge mistake, and I need a more definitive answer than I can find on the Internet.

I presently live in a brick veneer home that was built in 1960. The brick is built approximately 1/2 inch to 3/4 inch from the wood frame of the house, which consists of standard 2 X 4 construction (depths of wall 3.5 inches). On the complete western side of the house, I just completed a retrofit where I did the following just months ago: (1) I removed all the sheetrock (2 foot width boards) and plaster. This exposed an interior that had no insulation. I could see the exterior sheathing which consisted of some type of dark, perhaps petroleum-based, wafer board about 3/4 inch thick. (2) I then used Owens-Corning fiberglass batts (pink) with facing and applied this to the 2 X 4 studding. I took my time doing this. (3) I then installed a 6-mil plastic vapor barrier on top of this faced insulation. (4) I then installed 7/16" oriented strand board next. (5) I then installed 1" of your Owens-Corning poly pink board on top of the OSB. (6) I then installed 1/2" of sheetrock on top of the pink board. Summary: Brick, a small air gap, dark waferboard, pink fiberglass insulation with facing, 6-mil vapor barrier, OSB, pink poly insulation sheets, sheetrock, and then paint.

After doing all of this, I was speaking to a mason and was horrified that I might have done something I shouldn't have. I also did quite a bit of research and have found data to be very sparse about renovating brick veneer homes with insulation. The mason seemed to think that I might have subjected the brick facade to potential damage and the interior insulation batts to moisture.

Please help me before there may occur any permanent damage to my home. Is there any documentation about insulating wood framed homes with a brick veneer? I need to know if I should go in there and take all of that out. I had thought about applying a brick sealant in the spring and retrofitting weep holes at the bottom of the brick. (I don't think there are any.) There seemed to be good air circulation when I was putting in the insulation and I would run my hand near the holes where the masons would put their level lines. I mean, these holes were in the wafer board and I could feel a positive air flow. I don't remember if it was coming in or going out, though.

Please help me. Anything you can provide would be appreciated.

Thanks

Not good, but not as bad as it would be if your house was in the south. What you need to do now is important since fixing the mistake may not be cost effective.

You need to make sure you have exhaust fans in the bathrooms, near the showers/tubs and make sure they are turned on before the water is run and for at least 10-15 minutes afterwards. These fans need to exhaust to the exterior.

Also make sure you have an exhaust vent over the stove that vents to the exterior.

Make sure you have a good vapor barrier on the ground under the house.

Make sure your gutters stay clean, keep thick plantings away from the house, keep surface water away from the foundation and don't let irrigation systems spray water on or near the house.

The amount of interior moisture depends on several items including number of occupants, size of house, height of ceilings, air leakage, outside weather.
If you have lots of interior moisture you will need a dehumidifier also.

Originally Posted by John Kogel

In my area, a poly vapour barrier is required on the innermost surface, directly behind the drywall. So there is no rule which fits every location.

Beaver board, blackcote, etc, is not prone to mold problems. The OSB is, it is a moisture sponge that turns black with mold before your eyes, especially with poly against the back side.

Thanks, John, and I think it might be blackcote, I wasn't overly concerned about it. I will take your advice up on that OSB, though. I have had similar experiences and seen where the OSB will turn black right before your very eyes. I do think they are using different glues these days, and various manuacturers are hip to the notion that their product is a magnet for mold. How do we trust that such advancements have been made, though?

There has been a lot of discussion, here, about vapor barriers. I was able to find some good literature about that. If anyone wants to know anything about vapor barriers, I would recommend reading the following. It also comes from a qualified, respectable source. I am also finding Building Science Corporation to be a wealth of information. But, like so many before them, their research covers load-bearing brick walls, and not brick veneer homes with wood frame construction. I would love to see someone take on the project and do, say, three model homes, and then go back each year for several years to see the results. In a cold climate, like the Midwest, per se?

Here is the site for the vapor barrier information:

http://www.ashrae.org/content/ASHRAE...612117_686.pdf

Again, thanks to all. I have gleaned some really good ideas for when I retrofit the other half of the house.

~Harry

As a final footnote, the Brick Institute of America now recommends that in brick veneer homes, the brick should be installed with a two-inch air barrier gap between the brick veneer and the exterior sheathing of the home. In my case, this house was built in 1960, when there were no such requirements. Presently, the gap is from as little as a half inch to as much as an inch. So, essentially, unless I can successfully control the moisture and vapor coming through the brick, I am destined to have moisture issues and/or damage to the brick facade. I guess this spring I must look into installing mechanisms to draw the water away from the inside of the brick and ensure adequate air circulation. That will be no small feat, considering how shallow of an air space I have to deal with.

Originally Posted by Harry Turner

As a final footnote, the Brick Institute of America now recommends that in brick veneer homes, the brick should be installed with a two-inch air barrier gap between the brick veneer and the exterior sheathing of the home.

In an effort to keep up with the latest industry recommendations I searched the BIA site looking for the 2" air space recommendation unsuccessfully, could you (or anyone) please provide a link?

Originally Posted by chris mcintyre

In an effort to keep up with the latest industry recommendations I searched the BIA site looking for the 2" air space recommendation unsuccessfully, could you (or anyone) please provide a link?

I have never seen such a recommendation either however the recommendation is to use mortar netting to catch the mortar snot from acting as a bridge for the water to cross over into the sheathing.
In my CE class we were taught how during the brick laying process the mortar drops down into the space and netting can help control that issue.
In order to create a 2 inch space the shelf or foundation wall would need to be extended and that also would require longer stronger brick ties I would think.

Originally Posted by chris mcintyre

In an effort to keep up with the latest industry recommendations I searched the BIA site looking for the 2" air space recommendation unsuccessfully, could you (or anyone) please provide a link?

IRC 703.7.7.2 Air Space
In the 2003 edition calls for a minimum of 1" to a maximum of 4.5" separation from the sheathing.

Anything over 1" does not allow use of standard corrugated sheet metal ties so if they go to a bigger gap, upgraded ties are required.
Again, this is 2003 IRC requirements, not latest industry recommendations.

Originally Posted by chris mcintyre

In an effort to keep up with the latest industry recommendations I searched the BIA site looking for the 2" air space recommendation unsuccessfully, could you (or anyone) please provide a link?

Please read what Dr. Lstiburek provides in reference to Assemblies 6, 8, and 9 at the following citation:

http://www.ashrae.org/content/ASHRAE...612117_686.pdf

Lstiburek, Ph.D, P.Eng., refers to recommendations from the Brick Institute of America as it pertains to brick veneers homes in what he has classed as certain areas in North America. You will have to read the area of applicability under each assembly to know where. The article is from August 2004, so perhaps the standard has changed once again. I don't know. Anyone on here who knows more about the Brick Institute of America?

Originally Posted by Jim Luttrall

IRC 703.7.7.2 Air Space
In the 2003 edition calls for a minimum of 1" to a maximum of 4.5" separation from the sheathing.

2006 IRC says the same thing in R703.7.4.2

Thanks for the link Harry, good article (other than the 2" air space thing )

The 2" air space would create issues at door and window openings, IMO the 1" air space works well as long as it is done properly as Bob has mentioned....at least in this part of the country.

brick is considered a reservoir cladding. That is it absorbs and holds moisture. Then when the sun comes out you get vapor drive out of the back side of the brick- towards the interior. An air space gives the vapor a relief valve. So its important to keep the air gap.

In a primarily heating climate your vapor drive is from inside to out. I would say the details are the air sealing at the interior foam. If the air does not carry moisture in to the wall then you have eliminated the largest moisture source. Diffusion through the material is not a problems. Your rigid insulation should suffice for a vapor barrier.

IF the interior rigid insulation is your vapor barrier then the poly and kraft facing become traps for moisture and shouldn't be there.

The exterior sheathing should be air tight but vapor permeable. The air gap between the brick will allow the wall to dry to the outside. Fiberglass does not work well in a leaky enclosure.

I would also recommend dense pack cellulose over fiberglass.