no housewrap...

[Jeff Six]

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.

[3D Peruna]

Did you buy the house new? Used? Did you have it built? What was your purchase situation? Can't help with suggested remedies until we know more.

As for not having a weather barrier between the siding and house -- that's huge no-no. Even out west were the air is mostly dry, it's a huge no-no. Every siding needs to be looked at as "thick paint." In other words, the purpose of the siding is to protect the weather barrier from the elements, most particularly the sun (which deteriorates just about every known weather barrier--tyvek or building paper). Siding will keep most of the water out, but you have to approach it from the viewpoint that, as one building scientist puts it, "things will get wet." If you assume that the siding won't keep all the water out, then you can properly manage the water that does get in. Leaving the tyvek, or building paper, or any other weather barrier off is not acceptable--at least not for me.

[m Ransley]

You want reasurance, well I had osb then Tyvek , the instaler screwed up the seams and now in some areas water is trapped and molding badly, it stinks and is swelling and distorting the OSB. With 4x8 osb you realy dont need tyvek as you have very small areas for air infiltration anyway. I will Remove problem areas of Tyvek.

[John Davies]

Personally I agree 100% that it's a good idea, but I don't agree that it is a necessity in all climates.

My new neighborhood in Spokane WA, with homes up to US$600,000, has mostly houses with no water barrier under the siding. Mine is included. If this were a problem in this climate, it would be required by code.

I did talk to a building inspector and my builder, and they told me it just was not needed here.

I would kind of liked to have it...

John Davies

'96 Lexus LX450 '00 Audi A4 1.8T quattro Spokane WA USA

[v]

I take it that if the house was in Seattle instead of Spokane, it WOULD be needed?

-v.

[Don Phillips]

If it is any consolation, building codes, the minimum standard, does not require a house wrap.

Sincerely,

Donald L. Phillips, Jr., P.E. Worthington Engineering, Inc.

145 Greenglade Avenue Worthington, OH 43085-2264

[e-mail] (remove NS to use the address)

614.937.0463 voice 208.975.1011 fax

[Tom Baker]

In my opinion, "thick paint" is overstating the protection given by vinyl siding.

I worked on a house with OSB and vinyl siding and no weather barrier. That arrangement had been in place for about three years. I could, without effort, push my hand through the OSB. Tom Baker

[Rusty]

There seems to be a misunderstanding here. Tyvek is not a moisture barrier. It is only put there to reduce the infiltration of air through the wall, which is where much of the heat gain or loss occurs. Tyvek or similar is not required by the building code so it is purely up to you and your builder if you want it. It is certainly good to have but not required by law.

[George E. Cawthon]

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 >

[3D Peruna]

[P.Fritz]

False.

If ten thousand people jump off a bridge, it doesn't make it right

the new issue of IBC will make it a requirement.

Poor construction practices (by some) is NEVER a reason to not install a material.

False, the tyvek is an air infiltration barrier and a secondary moisture barrier

No, they used building felt for the same purpose, but it wasn't as effective

False

[3D Peruna]

"The primary function of a housewrap or building paper is rain penetration control. It is not air infiltration despite what the manufacturers say. The energy aspects of housewraps are vastly overstated. They have been embraced by builders for this function as can be evidenced by their market penetration. Yet their critical role in building durability is under appreciated and not marketed. It has been a triumph of marketing over physics." -- Joseph Lstiburek, Ph.D., P. Eng.

[v]

That's wrong. One of the very earliest basic tech classes from when I was in architecture school, stressed that the building paper (this was before Tyvek) was what really kept the water out of the house, and that the siding mainly protected the paper. Take as an example a brick veneer wall where the brick is the "siding". The brick is built a small distance away from the sheathing and there will be weeps at the base of the wall to let water out. The people who built tarpaper shacks knew which layer kept the water out - beter to skip the siding than the tarpaper!

The reason Tyvek was an advance is that it still deflected liquid water (like tar paper before it) but it let vapor pass out of the house and not condense and freeze inside the cavity (more important now that houses are better insulated).

-v.

[P.Fritz]

Sorry but you are wrong.....a moisture barrier is required under the exterior veneer under the 2000 International Residential Code...specifically building felt or 'other approved material'

[Don Phillips]

Code...specifically

The OP was referring to siding, not a veneer.

Sincerely,

Donald L. Phillips, Jr., P.E. Worthington Engineering, Inc.

145 Greenglade Avenue Worthington, OH 43085-2264

[e-mail] (remove NS to use the address)

614.937.0463 voice 208.975.1011 fax

[P.Fritz]

...............that is what the siding is.

[Don Phillips]

My house has been fine since 1973.

I just looked at Table R703.4 in the 2003 IRC and no sheathing paper is required. I do not recall seeing this in the 2000 IBC. Can you give me the code reference in the 2003 IBC?

Agreed.

Sincerely,

Donald L. Phillips, Jr., P.E. Worthington Engineering, Inc.

145 Greenglade Avenue Worthington, OH 43085-2264

[e-mail] (remove NS to use the address)

614.937.0463 voice 208.975.1011 fax

[George E. Cawthon]

He has some points, but he is basically full of crap about the purpose of house wraps; house wraps are designed to limit air infiltration without eliminating movement of gaseous water. The purpose of the siding is to limit or eliminate water penetration to the structure. The very outer layer needs some ventilation and drainage to get rid of any water that does penetrate the siding. Whether a house has a housewrap or not, it needs to be constructed to limit water penetration past the siding. There are many houses that have stood for hundreds of years because they were constructed to reduce/eliminate moisture penetration without house wraps and calks. You construct a house the same way whether you use a house wrap or not.

[George E. Cawthon]

What's false? What IS the purpose of the siding?

That doesn't make sense. Are you suggesting people shouldn't have built houses before Tyvek was invented?

Are you implying that Tyvek will be required by all local building codes?

No one said it was. Just stating a fact about poor construction.

And I didn't say that the purpose was an air infiltration barrier?

Oh? a poorly constructed or damaged moisture barrier on the inside of the wall and an effective moisture barrier on the outside of the wall wouldn't lead to moisture trapped in the wall?

[George E. Cawthon]

Good old Joe is full of bunkum. The manufaturer makes the product and says what the purpose is. Essentially thay say use this product will reduce air infiltration and save you money. Now it may not save money, but they do say what the purpose is. Along comes Joe who decides that the purpose of the product is something else. Something is a little wrong with this picture. I think the manufaturer determines the purpose.