Tyvek degradation

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Author Message David Axt, AIA, CCS, CSI Senior Member Username: david_axt Post Number: 688 Registered: 03-2002 Posted on Tuesday, August 08, 2006 - 01:04 pm:    I sort of remember seeing an article saying that unprimed cedar siding and cementitious board (James Hardie) siding will destroy Tyvek building wrap. Something about the tannins in the cedar and alkali in the Hardie board will eat away at the material. Can anybody confirm or deny this? Julie Brown Senior Member Username: jkbrown Post Number: 6 Registered: 06-2004 Posted on Tuesday, August 08, 2006 - 01:33 pm:    Yes, that is correct. The acids in Cedar and Redwood, and the salts in concrete and concrete based products like Hardiboard degrade the paper. Jerome J. Lazar, RA, CCS, CSI, SCIP Senior Member Username: lazarcitec Post Number: 251 Registered: 05-2003 Posted on Tuesday, August 08, 2006 - 01:40 pm:    Julie Can you offer a source on that statement? Julie Brown Senior Member Username: jkbrown Post Number: 7 Registered: 06-2004 Posted on Tuesday, August 08, 2006 - 02:08 pm:    Destructive testing that has been performed in California and Nevada. David R. Combs, CSI, CCS, CCCA Senior Member Username: davidcombs Post Number: 157 Registered: 08-2004 Posted on Tuesday, August 08, 2006 - 02:35 pm:    What, then, is one to make of Tyvey's "Stucco-Wrap" product, purportedly designed specifically for installation behind stucco? Is that, too, subject to the same degradation, since stucco is a cement-based product? Anne Whitacre, FCSI CCS Senior Member Username: awhitacre Post Number: 373 Registered: 07-2002 Posted on Tuesday, August 08, 2006 - 03:14 pm:    this has been the topic of a LOT of lawsuits in the northwest. not only does the Tyvek degrade in that environment but the accumluated moisture ends up rotting the studs (no matter what wood they are) and destroying much of the rest of the framing. The web sites for both Tyvek and also the red cedar folks now recommend completely backpriming any wood siding (or shingles) that is in contact with Tyvek; apparently this will prevent the contact of lignin with the housewrap. in this instance, the lignin and to some degree, the oils in the wood, act as saponifiers to destroy the air barrier qualities of the housewrap. Keep in mind that Tyvek also will only barely diffuse moisture that gets behind it, so that if there is a leak of any sort, most of that moisture will remain in the cavity. Julie Brown Senior Member Username: jkbrown Post Number: 8 Registered: 06-2004 Posted on Tuesday, August 08, 2006 - 03:29 pm:    I have not seen or heard of the same problems with Tyvek's Stucco-Wrap. Actually the destructive tests have shown that Stucco-Wrap holds up well and does not have the same problems as the Tyvek Housewrap. There are problems with penetrations that are not sealed, but no degradation. Robert E. Woodburn Senior Member Username: bwoodburn Post Number: 128 Registered: 01-2005 Posted on Tuesday, August 08, 2006 - 03:36 pm:    So, is "Tyvek Cedar-Wrap" in the works...? Or "Tyvek Cement-Fiber Wrap"? J. Peter Jordan Senior Member Username: jpjordan Post Number: 199 Registered: 05-2004 Posted on Tuesday, August 08, 2006 - 03:50 pm:    A comment on the observation that moisture remains in the cavity behind Tyvek. When you think about any materials' ability to "breathe" (one of Tyvek's selling points), you have to remember the mechanics at work. In most of the US, Tyvek will allow water vapor to diffuse out of the building while keeping moisture out. This is because that much of the year the water vapor content inside the building is higher than outside the building. This creates the vapor pressure that "drives" the water vapor out of the building. However, in certain climates, the Gulf Coast is one of them and perhaps wetter parts of the North West, the vapor pressure almost always is driving water vapor toward the inside of the building. Any leak in the envelope merely adds to the water vapor inside (usually handled by the A/C system) or adds to the conditions creating mold growth. In this condition, it seems to me that Tyvek will "breathe" water vapor to the inside of the building creating a less than desirable condition. It is my view that Tyvek may be an appropriate material for use in a generally drier climate than we usually have in Houston, and it seems to me that conditions may be similar in certain parts of the North West as well. William C. Pegues, FCSI, CCS Senior Member Username: wpegues Post Number: 615 Registered: 10-2002 Posted on Tuesday, August 08, 2006 - 04:14 pm:    Peter, Then what material would you propose for an air barrier (vapor permeable) material? In the climate zone that the new 2006 ibc code will use, and the design principals that are currently in common use, a line runs across the country at so that all south of the northern border of MD as it continues west over Texas, dives across the south of NM and AZ and then goes back up the west coast, all areas 'south' of that line no vapor barrier is recommended. In addition, if a barrier is used, it is recommended to be vapor permeable. In he aea of Gulf Coast, Pacific North West as you list, the new recommendation based on studies of walls you either use a vapor permeable air barrier, or nothing. Non-vapor breathing barriers are not recommended for use at all in these areas. Anonymous   Posted on Tuesday, August 08, 2006 - 01:56 pm:    Joe Lstiburek - buildingscience.com. Look for technical paper posted on web site about this, search for 'surfactant'. Phenomenon not limited to building wrap products, impacts all weather resistant paper products. David Axt, AIA, CCS, CSI Senior Member Username: david_axt Post Number: 689 Registered: 03-2002 Posted on Tuesday, August 08, 2006 - 09:05 pm:    Here is another interesting Tyvek fact. One of the guys in my office loves to go hiking and camping. He bought a large sheet of Tyvek HouseWrap to use as a ground cloth. His theory was that Tyvek is lightweight, hard to tear/puncture and breathes. So he could put his ground cloth on the frozen ground and the Tyvek would allow his perspiration to escape while preventing the ground moisture from getting into his sleeping bag. It was a very sound theory. In reality though, once the Tyvek got cold it tore, in his words, "like dry newspaper". It was a total shredded so much that he ended up tossing it in the nearest park trash bin. This makes me wonder about the brittleness of Tyvek in buildings. Throw a snowball at the side of a house and the Tyvek shatters like glass behind the siding. ???? Jennifer Young, CSI, CDT, MAI Senior Member Username: jenn Post Number: 6 Registered: 04-2006 Posted on Wednesday, August 09, 2006 - 09:54 am:    I used to work for a Tyvek distributor and I contacted my old friends to get some info - if you are interested in me passing it on, please e-mail me. Jennifer Young, CSI, CDT, MAI Senior Member Username: jenn Post Number: 7 Registered: 04-2006 Posted on Wednesday, August 09, 2006 - 09:55 am:    whoops - jyoung@interiorinvestments.com David Axt, AIA, CCS, CSI Senior Member Username: david_axt Post Number: 691 Registered: 03-2002 Posted on Wednesday, August 09, 2006 - 01:53 pm:    A previous coworker informs me that I gave him an article from Fine Homebuilding magazine that describe just the Tyvek problems that we are discussing here. I must be having a "junior moment" because I can not seem to locate the article. I will try contacting the publish or search the website. Ralph Liebing, RA, CSI Senior Member Username: rliebing Post Number: 449 Registered: 02-2003 Posted on Wednesday, August 09, 2006 - 02:14 pm:    C'mon, David, "junior moments" are: -a wet diaper -having to eat strained peas -you fall over when your dog licks your face -your knees constantly have rug burns -your "nap" is 4 hours long -Aunt Bessie always pinches your cheeks-- hard! David Axt, AIA, CCS, CSI Senior Member Username: david_axt Post Number: 692 Registered: 03-2002 Posted on Wednesday, August 09, 2006 - 03:24 pm:    Ralph, Okay so maybe I am not THAT young. But pretty darn close! BTW, - a wet diaper - having to eat strained peas - your "nap" is 4 hours long also applies to "senior moments". Anyhow............ I found the article. It's from the February/March 2001 issue of Fine Homebuilding. Basically it is a short article from Joseph Lstiburek. E-mail me (daxt@bassettiarch.com) and I will shoot you over a PDF copy. Ron Beard CCS Senior Member Username: rm_beard_ccs Post Number: 148 Registered: 10-2002 Posted on Wednesday, August 09, 2006 - 03:39 pm:    Has Tyvek ever been tested for use in wet diaper conditions? caseyrobb (Unregistered Guest) Unregistered guest Posted on Tuesday, August 15, 2006 - 05:16 pm:    Hello 4-specs chat on Tyvek. Would highly recommend you contact DuPont for comment and rely on the facts. Get a valid response to your concerns by calling 1-800-44-TYVEK. You will be directed to a technical team for questions, comments on the facts, further recommendation, and who to contact locally for help on your specific project!!! Ellis C. Whitby, AIA, PE, CSI Senior Member Username: ecwhitby Post Number: 19 Registered: 03-2003 Posted on Thursday, August 17, 2006 - 10:35 am:    Jennifer; I would be interested in any information you have. It is always nice to have info to campare with the manufacturers statements. ellis.whitby@hdrinc.com