Tyvek Wrap

[Bob]

What are the implications if a newly-constructed house does not use tyvek wrap?

[Art]

Dupont doesn't make any money on it...

[david ashworth]

I like the TYVEK material. It has kevlar in it. Very difficult for water to transmit thru. If applied correctly, with tape, and ice and water over window flanges ,I believe it is a superior product to our weather in the Northeast. If you live in a dry climate , I guess it would not make a difference which product you used. I have been told some areas of the country require no building wrap. I have no knowledge of other areas. fastening techniques vary ,check their website. Off to football!

[SteveF]

Depends.

If it's a concrete block house in Hawaii it's not going to make a bit of difference.

If it's a standard 2 x 4 walls, OSB in corners, with black board sheathing under vinyl siding in North Dakota - get ready for some pretty steep heating bills.

Steve.

[Michael Bulatovich]

Where? Made of what?

[Bob]

Made of Tyvek. Wrapping the house.

[SteveF]

I think the point a couple of us are trying to make is that some details of the construction and location of the house would give us a shot at helping you out. If you want generalities of what Tyvek does, that can be found on DuPont's web site.

Steve.

[Michael Bulatovich]

Seriously, I meant the geographic location (climate ),and house construction. It's relevant to any discussion you want to have about materials. Don't you think?

[RicodJour]

Tyvek is made from spun-bonded polyethylene. There is no Kevlar in it.

R

[Bob]

Ahh - I get it. South central Texas. Wood frame house with stone exterior and some hardiboard (sp?). The hardiboard is backed by that plywood-like material. The stone is backed by some kind of foam-board and the plywood-like material at any corners. House will be sealed with expanding foam at all penetrations, including windows and doors.

Bob

[marson]

There are two functions of Tyveck (besides making a profit for Dupont!) First and foremost, it serves as a barrier against water intrusion primarily from wind driven rain. You don't have to use Tyveck BTW. 30# felt works too, and in fact is preferred by some people because of it is more permeable to water vapor that Tyveck.

The second is to serve as an air barrier. In cold climates, cold air leaks can strip the R value from your insulation. Not sure if this is a factor in South Texas.

I have at times questioned the value of Tyveck in some applications, but in the end, it's good cheap insurance and use it all the time.

[Bob]

Thanks for the good info and insight.

Seems that this may be less important in my situation, although I wish the builder had used it. The builder tells me that with the plywood-like 4x8 sheets behind stone, tyvek is less of an issue and that the foam sheets behind the hardiboard have a built in plastic covering that does much the same as tyvek. I think this may be a bit of a stretch on his part. I think the plastic covering on the foam boards is for protection during shipment/handling. It is already starting to peel off.

But, I think the expanding foam that will be used to seal all the cracks and other leak-points will cover the air-leakage point. Also, the exterior walls are 2x6 and will have R19 insulation.

Any comments?

Bob

[david ashworth]

try this link