Replies

1. 
   andy_engel | Mar 24, 2009 09:12pm | #1

   Any. Just install it so the upper layers lap the lower like shingles, and don't leave it in the sun too long.

   Andy

   "Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)

   "Get off your dead #### and on your dying feet." Mom

   "Everything not forbidden is compulsory." T.H. White, The Once and Future King

1. 
   blownonfuel | Mar 24, 2009 09:54pm | #2

   Thanks Andy. Do they make tape for felt, to seal the overlaps?

1. 
   andy_engel | Mar 25, 2009 03:50pm | #14

   I wouldn't bother to tape either one. Taping is mainly done to minimize exterior air infiltration. Assuming that you sheathe with plywood or osb, not a lot of air is going to get past the sheathing. Actually, I'd probably go with ZipWall and skip the building paper entirely.Andy

   "Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)

   "Get off your dead #### and on your dying feet." Mom

   "Everything not forbidden is compulsory." T.H. White, The Once and Future King

1. 
   DanH | Mar 25, 2009 04:28pm | #15

   It's amazing how much air can get past sheathing, but air infiltration isn't likely that big a deal in Texas.
   The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith

1. 
   Ted W. | Mar 29, 2009 12:04am | #31

   It's amazing how much air can get past sheathing, but air infiltration isn't likely that big a deal in Texas.

   Why is that. Ain't thar no wind in Texas?~ Ted W ~

   Tool Auctions - MyToolbox.netSee my work - TedsCarpentry.com

2. 
   Jeff_Clarke | Mar 29, 2009 01:55am | #32

   Mostly hot air ... ;o)

   Whoops ....

   View ImageJeff

   Edited 3/28/2009 10:29 pm ET by Jeff_Clarke

3. 
   DanH | Mar 29, 2009 02:58am | #33

   In Texas they don't have the common sense to shut the windows anyway, so it doesn't make any difference.
   The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith

4. 
   Ted W. | Mar 29, 2009 11:45am | #34

   Why bother? It never rains there.

    

   Oh, wait... That's souther California~ Ted W ~

   Tool Auctions - MyToolbox.netSee my work - TedsCarpentry.com

2. 
   blownonfuel | Mar 25, 2009 05:10pm | #16

   What is ZipWall Andy?

1. 
   davidmeiland | Mar 25, 2009 06:01pm | #17

   It is a highly vapor-impermeable version of OSB intended to be used with tape and without wrap. Seems like a great way to create a wall that cannot dry easily to the outside. It would be at the bottom of my list for sheathing. The roof product might be OK but I would still felt it before roofing.

2. 
   andy_engel | Mar 25, 2009 06:46pm | #18

   ZipWall is a Huber product with an integral weather barrier in lieu of housewrap or tarpaper. All you need to do is tape the seams. I don't share Dave's concern about it being highly impermeable. OSB sheathing on its own is essentially a vapor retarder anyway. I'd avoid using an interior vapor retarder with ZipWall, but I do my best to avoid interior vapor retarders, anyway. Because most houses are sheathed with OSB, we regularly build walls that don't dry well to either side. It also depends on your climate. If you're in a hot, humid climate, you want the vapor retarder on the outside anyway. My only concern with ZipWall is that flashing openings relies entirely on the adhesion of the peel and stick.Andy

   "Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)

   "Get off your dead #### and on your dying feet." Mom

   "Everything not forbidden is compulsory." T.H. White, The Once and Future King

3. 
   blownonfuel | Mar 25, 2009 08:35pm | #19

   Thanks for all the help guys.

4. 
   andy_engel | Mar 25, 2009 10:05pm | #20

   Help? You'd have to be a genius to come away from here with answers instead being even more confused. <G>Andy

   "Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)

   "Get off your dead #### and on your dying feet." Mom

   "Everything not forbidden is compulsory." T.H. White, The Once and Future King

5. 
   blownonfuel | Mar 25, 2009 11:34pm | #21

   LOL.

6. 
   eleeski | Mar 26, 2009 08:51am | #22

   We used Greenguard foam boards on the outside of our Tahoe house. The Greenguard gives a bit of insulation and it has built in drainage channels. I don't know about the inspector because the stucco guys put paper over the Greenguard. But the walls are dry even with snow packed against the stucco.

   Between the fiberglass and the Tigerfoam in the bays and the Greenguard outside the house is very well insulated and it stays comfortable with the heater barely running.

   Eric

7. 
   blownonfuel | Mar 26, 2009 07:37pm | #23

   Thanks Eric.

8. 
   davidmeiland | Mar 26, 2009 08:26pm | #24

   >>we regularly build walls that don't dry well to either side

   I'm trying to wrap my head around this one. It's not easy. Why wouldn't you try to build a wall that dries well? Choosing materials that inhibit this makes no sense.

9. 
   andy_engel | Mar 26, 2009 10:11pm | #25

   I'm not saying it's desirable. I'm saying that using OSB sheathing and an interior vapor retarder creates a wall that doesn't dry well to either side. Get a copy of Bill Rose's book, Water in Buildings.Andy

   "Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)

   "Get off your dead #### and on your dying feet." Mom

   "Everything not forbidden is compulsory." T.H. White, The Once and Future King

10. 
    davidmeiland | Mar 26, 2009 10:53pm | #26

    Right... so why recommend ZipWall?

11. 
    andy_engel | Mar 26, 2009 11:39pm | #27

    In mixed and hot climates, I don't see a downside. The assumption is that for about half the year in mixed climates, drying takes place inward, and for half the year it takes place outward. As long as you air seal well, and use the highest perm vapor retarder inside as you can, I'd be surprised to see a problem with designing a wall to dry inward. The advantage of ZipWall is that detailing the exterior becomes nearly idiot proof. In my experience, walls are far more likely to have moisture problems related to exterior leaks from faulty installation of flashing around penetrations than because of vapor diffusion from inside. In most cases, vapor diffusion is a pretty minor component, even compared to moisture carried in on air leaks. In the OP's case, he's building in Texas. Most of Texas is a hot climate, so any vapor retarder would go on the outside as a matter of course. In that case, ZipWall seems like a no-brainer.Andy

    "Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)

    "Get off your dead #### and on your dying feet." Mom

    "Everything not forbidden is compulsory." T.H. White, The Once and Future King

12. 
    andy_engel | Mar 27, 2009 12:09am | #28

    Dave, let me expand that. I had assumed that Zip Wall had a pretty low perm rating, but that's not the case. Depending on the source, the perm rating of OSB or 1/2 in. plywood sheathing ranges between 3 and .7. It passes less water vapor than tar paper. The published perm rating for the water resistant face of ZipWall is 12 to 16, which is higher than tarpaper and a lot of housewraps, and higher than the underlying OSB. It's hardly what I'd call a vapor barrier. The focus on vapor transmission is a bit of a red herring for most of us anyway. Sure, in the far north the vapor drive may be enough to create trouble. But for the rest of us, the keys to water in framing cavities are controlling air leaks and bulk water intrusion, while allowing for some drying.Andy"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)"Get off your dead #### and on your dying feet." Mom"Everything not forbidden is compulsory." T.H. White, The Once and Future King

    Edited 3/26/2009 5:10 pm ET by Andy_Engel

13. 
    blownonfuel | Mar 28, 2009 06:15pm | #29

    Is was reading "Residential Framing" by William P. Spence and noticed that in some areas they put felt between the outside studs and sheathing. Why do they do that?

14. 
    DanH | Mar 28, 2009 08:28pm | #30

    Not uncommon with old plank sheathing. Helps reduce air infiltration (though not nearly as well as housewrap would).
    The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith

2. 
   IMERC | Mar 24, 2009 11:53pm | #3

   felt and hardie were meant for each other...

    

   Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming

   WOW!!! What a Ride!

   
   Forget the primal scream, just ROAR!!!

    

   "Some days it's just not worth chewing through the restraints"

1. 
   DanH | Mar 25, 2009 03:15am | #4

   I thought in Texas they always used tortillas for their wraps.
   The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith

1. 
   blownonfuel | Mar 25, 2009 05:20am | #7

   Corn or Flour? They actually absorb moisture pretty good. LOL.

1. 
   IMERC | Mar 25, 2009 05:21am | #8

   it's adobe dirt... 

   Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->

   WOW!!! What a Ride!

   Forget the primal scream, just ROAR!!!

    

   "Some days it's just not worth chewing through the restraints"

2. 
   davidmeiland | Mar 25, 2009 05:22am | #9

   I use felt, but if I were using wrap it would be Typar.

1. 
   blownonfuel | Mar 25, 2009 05:25am | #11

   Thanks D.

2. 
   Jeff_Clarke | Mar 25, 2009 06:31am | #13

   What David said.

   Jeff

3. 
   DanH | Mar 25, 2009 05:28am | #12

   I think I had Typar at Taco Bell.
   The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith

2. 
   blownonfuel | Mar 25, 2009 05:19am | #6

   Awesome.

3. 
   Dinosaur | Mar 25, 2009 03:29am | #5

   I've used both. Tyvek¯ etc. is faster; 15# felt is more economical.

   Assuming proper installation, both will cut wind infiltration; felt will repel liquid water better.

   There may be heat issues with felt in a climate like Texas; possibly the newer synthetics are more resistant to high temps. I don't know about that from personal experience. Hottest I've ever seen it get up here is about 38ºC (99ºF).

   I understand that qualifies as a cool spring day down there....

    

   Dinosaur

   How now, Mighty Sauron, that thou art not brought
   low by this? For thine evil pales before that which
   foolish men call Justice....
   

   

1. 
   blownonfuel | Mar 25, 2009 05:22am | #10

   99 deg. Nice and cooool. I don't even turn the a/c on till it gets over 100. JK.Thanks for the info.