Latest Discussions : Miscellaneous

melbaker12

06:12AM | 02/19/05
Member Since: 02/18/05
2 lifetime posts
I'm planning to build a house on the northern coast of Oregon. I have talked to two builders and received conflicting information. Builder A said he wraps the outside walls with Tyvex because building paper causes mold to form. Builder B said he wraps the walls with building paper because Tyvex causes mold to form. Can you provide any more information?

tomh

07:08AM | 02/19/05
Member Since: 07/01/03
549 lifetime posts
Your region may have sustained cool foggy weather and high moisture. Mold, algae and other growths can be found on any surface that provides a moisture and food source. Tyvek is permeable to air and vapor and is an inorganic spun-bonded polyetylene fiber. Like plastic (polyethylene sheet)it does not support mold growth; but unlike plastic, it can breath. This actually promotes drying in the wall void. Since moisture is persistent on the PNW coast, moisture traped between the barrier and organic siding may cause mold growth on siding.

On the otherhand, building paper is an organic felted paper and can absorb moisture and support mold. Felts are normally asphalt saturated to form an effective weather barrier and used as roofing felts and weather barrier under siding. Asphalt saturated felt does not breath. Under persistently moist conditions, this surface is more likely to trap moisture aginst siding or sheeting, and support mold and other plant growth due to the absorbent organic felt core and breakdown of the asphalt. Felt is less expensive, easy to apply, and is more easily damaged during construction.

Tyvek and other spunbonded synthetic fibers allow air to move slowly through building shell promoting drying, but stops wind and liquid water. In this case, it is a clearly superior modern product. In most installations, either felt or spun-bond barriers will work fine. The extra expense of the synthetic barrier is probably worthwhile for you.

carlbrown

09:26AM | 02/19/05
Member Since: 01/05/05
83 lifetime posts
Truth be known you need a layer of both. Put the house wrap on first then the building paper. The wrap will breath and the tarpaper will keep water out! I have a test result you might be intersted in about tyvek,tarpaper,and grade D paper. My email address is cbrown86@kc.rr.com if you email me i will send you the test results. Or i have a website and a toll free # there you can reach me at. www.badstucco.com there are some pictures there of house wrap that is installed wrong that might help you when they buid your house. As far as what you are looking at.

carlbrown

09:43AM | 02/19/05
Member Since: 01/05/05
83 lifetime posts
And another thought. There is a product on the market called greenguard put out by pactiv. For a drainage plane I think it is superior to tyvek!!! It has horizontal webbing and really wicks the water out the bottom of the wall. It is a directionaly installed product. And you will have a very hard time compressing it enough to keep it from working unlike tyvek.Ther is a link to greeguard on the badstucco website.

carlbrown

09:44AM | 02/19/05
Member Since: 01/05/05
83 lifetime posts
I meant vertical webbing!


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