# Exterior wall with T1-11 siding



## dalepres (Mar 20, 2011)

We're planning to use T1-11 siding on our new house initially with a probable upgrade later on. Our thought was insulated walls with OSB sheathing, then Tyvek, then air gap, then the T1-11.

If we use the T1-11 as sheathing, wouldn't we have to put our vapor barrier on the inside of the insulated walls rather than outside?

For the air gap, I saw a picture online of a yellow plastic product for providing an airgap between cladding and housewrapped OSB: http://www.buildingscience.com/documents/insights/bsi-038-mind-the-gap-eh.

Does anyone know what that is, where to find it, etc? I can't find anything other than this article that shows that product.

Any suggestions on our wall will be appreciated.


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## Tom Struble (Dec 29, 2008)

http://www.benjaminobdyke.com/visitor/product/key/homeSlicker

where to put the vapor barrier depends on your location


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## Gary in WA (Mar 11, 2009)

"If we use the T1-11 as sheathing, wouldn't we have to put our vapor barrier on the inside of the insulated walls rather than outside?"----------------------------- Are you confusing a Vapor Barrier with a Water Resistive Barrier? 

Where are you located?

Gary


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## pyper (Jul 1, 2009)

Isn't it T-111?

Anyway, where I live, the only vapor barrier that's necessary is the craft paper facing on the insulation. So a wall would look like this in section:

T-111 | Stud with batt insulation (facing towards interior) | drywall

In the future, when you want to upgrade the appearance of the house, you can put vapor permeable foam insulation on the T-111, and then Hardi plank, vinyl, stucco, or whatever you want. Or you can skip the foam and nail vinyl right to the T-111. 

Although I really dislike T-111 on a house, it is the fastest, cheapest way to get an exterior that a bank will convert to permanent on, and it is relatively easy to upgrade later.


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## dalepres (Mar 20, 2011)

I'm in Oklahoma. We have very hot summers with A/C going inside and cold - below zero - winters.

GBR, I probably am mixing water barrier with vapor barrier - though most of the literature I read doesn't separate the two. I would appreciate any help in clearing that up. As far as my understanding goes now (which I admit is not fully developed) I am planning, from the inside out: 1/2" drywall, 2x6x10' wall with fiberglass insulation (not sure if it should be faced or not faced?), OSB sheathing, TYVEK housewrap, air gap, T1-11 siding, paint.

With Pyper's idea, if I could save a couple thousand dollars on sheathing, that would be great. But I don't want to risk the integrity of my wall - from a moisture perspective. I am definitely interested in where this discussion is going and learning how to get this right so please continue.

Regards,

Dale


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## dalepres (Mar 20, 2011)

pyper said:


> Isn't it T-111?


http://www.apawood.org/level_b.cfm?content=prd_sid_main


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## Gary in WA (Mar 11, 2009)

http://www.energysavers.gov/your_home/insulation_airsealing/index.cfm/mytopic=11810

http://www.greenbuildingadvisor.com/blogs/dept/musings/vapor-retarders-and-vapor-barriers

http://www.buildingscience.com/docu...sheet-310-vapor-control-layer-recommendations

Ask your B.D. on vapor barrier or retarder required; find your Zone on map or City below map; http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_11_sec001_par001.htm


Zone requirements;http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_6_sec001_par003.htm

Gary


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## jklingel (Dec 21, 2008)

And if I may add, make sure someone reads you the code, or you read it. "Vapor retarder" is sometimes misinterpreted as "6 mil poly", which may be disastrous with air conditioning. And too, leave the fiberglass batts at the store. Rock wool, cellulose (batts or dense packed), cotton, or wool batts are better insulators (unless FG has gotten much more dense of late). Dense packed fiberglass does well, too. FG batts aren't that great.


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