Message Board Thread - "Wet sheathing behind brick veneer"

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Wet sheathing behind brick veneer divelikeit 8/10/2005
Has anyone found moisture found behind brick veneer? I have a client that has a condominium that is wood framed with 5/8 drywall on the exterior, 30lb paper and brick veneer facing. (Almost a EIFS type system but with brick) They have known water intrusions. My initial thought would be if it is wet enough, the thermal bridging should show some type of differential in the IR image.

Any thoughts, images or papers regarding this concept.
 
Re:Wet sheathing behind brick veneer roofman 8/11/2005
I would expect this situation to be similar to a ballasted single ply roof. (which is very difficult to scan due to the stone ballast) The brick in this situation has a huge amount of thermal mass requiring the use of a very narrow tempreature differential range to scan for. If I was asked to "attempt" a scan on this wall. I would do two things

1. wait until a good wind driven rain has occured recently
2. then wait for hot day - cool+clear night to scan just after dark OR wait for a cool night - bright+warm morning

Then look for the thermal inversion that should occur at the saturated areas. i.e. the wet areas should stay a bit warmer into the night and/or a bit cooler longer into the morning. But this will be a very narrow viewing window of the "thermal inversion" and due to the high thermal mass of the brick the temperature differential will be very small.

Sounds too easy BUT this "contractor's method" has been useful on many smooth surfaced roofs. If you catch the right atmospheric conditions and the water saturation is severe enough, the wet areas will actually be below the dew point and the dry areas above it. Basically there will be dew plainly visible on the wet areas and easily marked. This is usually only usefull in the deep south where the air temp and dew point are really close (super high RH%)

Best of luck
 
Re:Wet sheathing behind brick veneer jimk 9/27/2005
I wouldn't expect to find anything using. I have inspected many similar problems and infrared has never helped. Remember that there is a drainage plain behind the brick veneer and the brick has enough thermal mass that moisture on the sheathing cannot usually be detected.
 
Re:Wet sheathing behind brick veneer Bald Eagle 10/25/2005
I just read this thread and a question comes to mind. The suspected moisture is behind the brick veneer and there is suppose to be a moisture/vapor barrier behind all of that. Now going on the fact that a brick is more porous than the cement, if the paper/moisture barrier is what is getting wet, then would not allowing the brick to be thermally loaded show a pattern of moisture. Of course you would need to determine the amount of moisture and thermal loading needed.
 
Re:Wet sheathing behind brick veneer thermoman 11/17/2005
A brick veneer wall is designed completely different than a roof assembly or an EIFS assembly in that there is an air space behind the cladding. This air space is generally accompanied with weep holes at the shlef angles and possibly venting just below these angles. Think about it guys, how does the mason built them without an air space?

The only time you don't see air spaces behind these exterior masonry walls is if they were installed first the interior walls were then installed afterwards. Again highly unlikely since they need to be laterally supported by the back up wall.

Anyway, the air space creates a thermal separator between the interior wall assembly and the exterior cladding and short of direct thermal bridging (brick ties, mortar droppings and displaced sheathing due construction difficiencies, the mositure within the sheathing will not affect the thermal performance of the masonry cladding.

You are looking at the wrong side of the wall if you want to see sheathing moisture. You should be looking at the wall from the interior since the sheathing is most likely not separated by an air space to the interior gypsum board surfaces.
 
Re:Wet sheathing behind brick veneer JNTOOLS 11/17/2005
I agree with thermoman. You should try to look at the issue from the inside. It is difficult situation to get definitive results no matter what approach you take. One of the clues you can look for is thermal anomalies on the surface of the gypsum board, they could be caused by moisture in the saturated sheathing, if the sun is beating on the brick and the conditions are correct the water will turn to vapor and will try to work its way to the cooler dryer interior. If there is fiberglass batting it will become damp, once it gets damp it will loose R value which you will see. I doubt if a non-penetrating moisture meter will pick-up the moisture unless the insulation is saturated. The problem is that anomalies caused by insulation can show up for several reasons, poor thermal contact, thin spots, compression, or insulation that has become wet.
 
Re:Wet sheathing behind brick veneer joscan 1/3/2006
Please realize that most/all of you are referring to a brick cavity wall. Although cavity walls are a very common facade detail, there is another very common detail called "MULTI-WYTHE brick facade. This wall system is actually 3 layers "wythes" thick of brick or a brick/block combo. Water intrusion from any point of the facade allows the water to flow in a very irradic pattern between the brick courses. We find water in this type of brick system with Infrared very often. I have to agree with the other replies, cavity walls are difficult to pinpoint water intrusion. NOTE: We perform a preliminary section determination of the facade prior to submitting an infrared proposal.
 
Re:Wet sheathing behind brick veneer Thermal Man 1/5/2006
I had the same problem a found it to be a flashing leak two story up and i had to tighten my span up and take the scan on hot day and cold night.hope this helps.

Thermal Imagers LLC.
Joe Footen
 
Re:Wet sheathing behind brick veneer Bald Eagle 1/24/2006
If you have any scans that you could post it would be helpful to understand why you came to the conclusions you did.
 
Re:Wet sheathing behind brick veneer Mason 10/11/2006
BrickVent by Masonryinnovations is a potential remidiation option
 


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