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View Full Version : So is OSB now a water resistant barrier?



Gary Burnett
10-30-2012, 04:12 PM
I inspected a finished new construction home today and the buyer said she had come by while they were putting up the brick and they were just putting up the brick veneer over wood. I asked her if they had house wrap over the wood and she said only around the windows. I walked down the block where a home was under construction and sure enough, they got brick ties nailed in the OSB sheathing. Got a little Thermo sheathing up there too. Behind the OSB and insulated sheathing there is a black plastic barrier.
Just seems to me the barrier should be between the brick and other stuff so the other stuff doesn't get wet and (pick one) rot - attract insects - mold - all of the above. Seems IRC 703 says this isn't the way things should be done.
Anyone out there care to pontificate?
Oh yeah, almost forgot this part. She said they asked the builder and he said they would do the house wrap but that was priced as and upgrade.
Here are a few pics.

Thanks

Eric Barker
10-30-2012, 04:37 PM
It's wrong! Makes me wonder what other bright ideas the builder had.

H.G. Watson, Sr.
10-30-2012, 05:11 PM
That looks like its Green (not structural panels) to me.

Nary a stud hit either.

As you describe, someone's color blind, can't read, or both; or cheatin'

Perhaps no plan reviewer or inspector in the jurisdiction?

Trouble brewing...

Garry Blankenship
10-30-2012, 09:55 PM
The areas that are not Tyvek'd are staged for masonary or brick veneer. Presummably the mason will be covering the OSB w/ what they feel is best, ( my best guess ). Something needs to be there.

Sorry; it looks like veneer tabs are on the whole exterior. I am mistaken.

Chris McIntyre
10-31-2012, 01:43 PM
Definitely wrong and around here would have to be inspected prior to veneer so adding as you go would not make sense, and with part of the ties in place I,m guessing that is not the plan.:)

My question is what is the wire/cable running along the wall and will it be left there? it appears to run behind the window flashing. (pic 2)

BARRY ADAIR
10-31-2012, 03:21 PM
not unusual in N. Central TX but always written up!

i've sent request for interpretation to numerous D/FW area Chief building officials supposedly applying 2009 IRC only to get this reply

"OSB may be installed as a substrate behind masonry or any siding without a weather resistive barrier when the OSB is manufactured and stamped as weather resistive."

waswood & cementitious gets the same pass

if any doubt contact them directly

Gary Burnett
10-31-2012, 04:09 PM
Barry,
Thanks for your reply. This is in Lewisville and I didn't see if the OSB had any stamp but will find out. Evidently the Lewisville AHJ doesn't have a problem with it.
Chris,
That wire/cable is the pest control tubing that they installed to juice up and let drip somewhere in the walls for killing little Texas bugs. I don't have much faith in the tubes. I've seen too many cut and damaged to think they would really do much good. More like eye candy to the homeowner.

Rolland Pruner
11-02-2012, 04:58 AM
Be sure the use of Tempered glass!! on thse windows. Close to flloor line.

Got to use proper water proofing behind the brick work!!

Mark Parlee
11-02-2012, 10:46 PM
I am in a case where thirty town home units were built under the 1982 UBC
Poorly done WRB to no WRB This case is going to trial on mainly the lack of a complete WRB.We are expected to win.

If you can make a case using the 1982 UBC you can definitely make it using later codes.
If the sheathing is weather restive the joints are not so a case can be made against the joints.
how do you counter flash the flashing? Normally with the WRB.
How do you counter-flash the thru wall flashing? Normally with the WRB.

These photos are after brick was removed and the damage that was revealed.
The third pic shows OSB behind brick where there was no applied WRB
The other three show Brick with WRB where moisture migrated thru the WRB due to solar vapor drive and capillary bonding at mortar squeeze out where it touched the WRB.

Eric Barker
11-03-2012, 05:59 AM
i've sent request for interpretation to numerous D/FW area Chief building officials supposedly applying 2009 IRC only to get this reply "OSB may be installed as a substrate behind masonry or any siding without a weather resistive barrier when the OSB is manufactured and stamped as weather resistive."

This is a primary problem with trying to adhere to codes and their interpretations - they don't necessarily follow building science. As far a OSB being labeled as weather resistive I'd venture to say that's more of a Billy Mays marketing ploy than factual.

Jerry Peck
11-03-2012, 03:04 PM
i've sent request for interpretation to numerous D/FW area Chief building officials supposedly applying 2009 IRC only to get this reply

"OSB may be installed as a substrate behind masonry or any siding without a weather resistive barrier when the OSB is manufactured and stamped as weather resistive."

This is probably what they are referring to: http://www.huberwood.com/main.aspx?pagename=zipsystemwalloverview

I doubt they are referring to regular OSB panels.

Steven Turetsky
11-03-2012, 08:24 PM
OSB is fine. The problem is with the WRB... or lack of. I am a proponent of liquid applied barrier.

Mark Parlee
11-03-2012, 08:29 PM
Steve, so am I.
I also like the idea of adding an additional layer behind brick that consists of an entangled mesh with fabric. This eliminates the potential capillary bond due to mortar touching the WRB or liquid applied membrane.

Steven Turetsky
11-03-2012, 08:42 PM
Steve, so am I.
I also like the idea of adding an additional layer behind brick that consists of an entangled mesh with fabric. This eliminates the potential capillary bond due to mortar touching the WRB or liquid applied membrane.

Hi Mark,

How's it going?

The mesh certainly sounds good. If only builders realized the the few dollars more that it costs to do a reliable WRB, will pay off in the future. I don't believe they have the foggiest idea.

BARRY ADAIR
11-04-2012, 04:44 AM
This is probably what they are referring to: http://www.huberwood.com/main.aspx?pagename=zipsystemwalloverview

I doubt they are referring to regular OSB panels.

Jerry,
it's TX we're discussing
backtrack to the OP
all AHJ replies have had similar photos attached to the RFI
it's Exposure 1 osb sheathing not any material that comes with a rated wrb coat from the mfr nor field applied

Jerry Peck
11-04-2012, 07:14 AM
Jerry,
it's TX we're discussing

Barry,

Oops ... I forgot it was Texas we were discussing ... :)


backtrack to the OP
all AHJ replies have had similar photos attached to the RFI
it's Exposure 1 osb sheathing not any material that comes with a rated wrb coat from the mfr nor field applied

Well, as you said ... ;) ... "it's TX we're discussing" ... :D