From: "George E. Cawthon" 
Newsgroups: misc.consumers.house alt.building.construction alt.home.repair alt.construction
Subject: Re: no housewrap...
Date: Wed, 19 May 2004 06:33:26 GMT

In a properly built house water does not pass through the siding to
the sheathing.  Siding is constructed to have the water run off. 
Thousand, ten thousands, even millions of house shed water perfectly
before tyveck was invented.  Lots of house still don't use tyvek, and
if you price a roll, you'll see why.  Besides, carpenters often ruin
the tyvek, even the sheathing, and never properly repair it, making
the tyvek only partially effective in reducing air movement through
the home.  BTW, the purpose of tyvek is not to shed water (although it
does), it is to reduce air flow without completely stopping the
movement of gaseous water.  I would prefer my house to be wrapped in
tyvek, but if it isn't I would get too upset.  No house built before
?1970? used tyvek.  

Tarpaper works good as moisture barrier and was ok in air leaky shacks
which allowed any accumulated humidity to be removed, but you wouldn't
want to use it under the siding in a modern house because moisture
would be trapped inside the walls.

Jeff Six wrote:
> 
> I have recently discovered that my house (I've been there a little
> over two years) does not have housewrap underneath the vinyl siding.
> Underneath is OSB sheathing and the vinyl is installed right on top of
> the OSB.  This is true of all of the houses in my development.  After
> looking around the newsgroups, I find the while housewraps are
> recommended, there appear to be tons of houses that have this same
> situation - vinyl siding installed directly over the wood/OSB
> sheathing.  After some rain, I've popped the siding a little so I can
> see under and don't see any rain or moisture on the OSB.
> Nevertheless, the paranoid in me is concerned.
> 
> I'm really looking for some reassurance here that this situation,
> while not the best in the world, is OK.  Little help?  Thanks.