Felt is the better choice.

http://forums.jlconline.com/forums/showthread.php?7279-Tyvek-or-15-lb-felt-behind-brick-veneer

This post was edited by robin0919 on Mon, Feb 17, 14 at 22:26

Thanks for the link. I've read so much, and can find pros/cons for each.

Didnt read the link, but have in the past.. 30 Lb felt is a better product...... as long as its installed correctly..

Its personal preference really but I think felt is better for the cooling dominated climates and south facing brick while tyvek is probably better in heating dominated climates. Tyvek is much more permeable than felt.

Brian,
What would you recommend for KY? It's basically a push for heat or cold dominated and varies day to day. I guess I'm asking what would be a good exterior wall for brick?

We are in South Carolina and are uing a Zip system under our brick.

Renovator,
I just checked out the Huber Zip System. It seems like a good product. Do you have any personal experience with it? If using this, doesn't it eliminate the wrapping for your window and door framing? How does it change those installations? Thanks

The Zip system uses a special tape to seal all joints and the edges of wall penetrations. Windows are flashed in the usual manner with whatever self-adhering flashing you like. Don't forget to roll the tape for good adhesion. Huber also sells a gun-grade liquid sealant for irregular penetrations.

The Zi system is convenient for builders unfamiliar with applying an acrylic membrane in the filed. But acrylic fluid/liquid applied barriers are the best and many companies sell them for commercial projects but they are slow to be adopted by homebuilders. Here are some of them: DuPont Tyvek Fluid-Applied WB"; STO Gold Coat; Grace Vycor enV; Parex Weathertex; Henry Air-Bloc; Senergy Senershield: BASF Enershield; Prosoco R-Guard.

When you drive by a multi-family or office building you don't see Tyvek flapping in the wind. These systems may add cost to a project but if plastic housewrap is not good enough for those projects, why is it good enough for yours?

Here is a link that might be useful: zip system tape

When it's my choice, I use felt. Getting the details right on housewrap is an uphill battle, at least when you're an occasional custom builder. On the other hand, brick paper is standard practice for masons. Indeed, on the first project where I used housewrap, the masons insisted on using the felt as well.

I'm sold on exterior XPS in our cold climate, so liquid barriers are out.

The belt and suspenders approach: housewrap and felt.

This post was edited by worthy on Fri, Feb 21, 14 at 17:30

When choosing a weather/air barrier, the wall system should be designed and a vapor mergence rating determined for the barrier before thinking about specific materials because that rating might change if plywood was used instead of OSB or exterior rigid insulation was used.

Typar over building felt over OSB might not allow enough drying to the outside in the winter in a cold climate. Building felt over plywood sheathing might allow too much moisture movement into the house in a warm humid climate.

So, when describing the material you like to use it would be helpful to say what perm rating you are trying to achieve and why. All of the many materials available will probably work well somewhere.

That's where I don't understand much about the perms. I live in KY and the weather is subject to change daily. This winter has been brutally cold and the summers are usually hot/humid. I'm just wanting to do what's best for my new home. I've noticed most new builds around here just use Tyvek or the cheaper "house brand" house wrap. The more I read about the Huber System, I'm thinking it may be my best option.

Perms arent the easiest subject to get a grasp on and Renovator is correct that as you add multiple layers the permeability is compounded. Just remember that most moisture damage is from bulk water leaks of poor flashing details and dont obsess over the perm stuff that you lose sight of the big picture. Air leaks are usually more damaging than vapor permeability problems.

Knowing a little about your plans or lack there of from the extra insulation thread there is an easy answer here; add foam sheathing. Either XPS or foil faced isocyanurate will improve your home big time and will handle the vapor permeability issues and more importantly, if you tape the seams well, the air leaks through the walls. If you use the Huber system, go with the ZIP+R product which has the foam sheathing already attached to the ZIP. Used it on two homes now and love it.

Energy consultantMarc Rosenbaum has little use for foam as an air barrier and when he uses Huber Zip he always adds housewrap.

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I've noticed most new builds around here just use Tyvek or the cheaper "house brand" house wrap.

Certain brands may be totally useless and here as drainage planes, which is the primary purpose of a housewrap; some are even deliberately perforated.

This post was edited by worthy on Sat, Feb 22, 14 at 19:35

Thanks for the input everyone. Would it be just as effective if a person used standard OSB sheathing, taped the seams with the Huber Zip Tape and then housewrap with Tyvek? Seems that would be a cheaper alternative than going strictly with Huber. I can get OSB for $8.99 sheet and Huber is $27.

Peel and stick tape applied to OSB usually needs a primer. If you get the details of the housewrap correct, it will serve as a drainage plane and the taped OSB as an air barrier. If the exterior sheathing is your only air barrier, all OSB not butting onto OSB should be caulked to the framing.

For thermal efficiency, I favour taped foam board followed by brick paper, even in your relatively mild climate.

Are you meaning foam board with no OSB? If I go with foam board over OSB, that would change my window jamb widths, correct?

Tyvek. Not grip right. Not green guard. Not felt paper. Tyvek. The numbers are there and they don't lie.

What numbers are those, bs? (lol, and I won't even go there!).

There is a rebate for the Huber system

http://www.huberwood.com/assets/user/media/Extension-2014-Huber-FirstTimeUserRebate-Builder-and-Salesperson.pdf