House Wrap

[brepanshek]

Does the 2003 version of the IECC or IRC require any type of "house wrap"?

The way I think I read the code is that it is not required. Please give me the law to follow. look this up in the IRC N1102.1.10

[mharmon1]

brian,
u need to check out IRC R703.1-R703.4 and the table R703.4

[brepanshek]

IRC R703.4 chart

I have vinyl siding exterior covering, so The way I read this, is it is not required. Do I have a " I agree" out there?

[Joe Funderburk, CMI]

This is in all my reports: "The wall sheathing beneath the siding may or may not be covered with a water proofing membrane, commonly called "house wrap". While not required, it is recommended but we do not verify its presence or absence."

[homebild]

House wrap is not required as a weather barrier under vinyl siding under the 2003 IRC...but an air barrier IS required under the 2003 IECC + 2003 IRC unless one uses other acceptable means to prevent air infiltration into the structure.

See Table R703.4 that sheathing paper is not required under vinyl siding,

Refer to N 1102.1.10 "Air Leakage" regarding the need for an air barrier or other methods to prevent air infiltration and exfiltration.

"...other sources of air leakage (infiltration and exfiltration) through the building thermal envelope shall be caulked, gasketed, weatherstripped, wrapped, or otherwise sealed to limit uncontrolled air movement."

So the correct answer is, that housewrap is not required under vinyl siding as a secondary weather barrier but is required as an air barrier if the owner has not sealed all joints between sheathing and studs and other framing members to restrict air flow.

[Marcel R. Cyr]

Is it the correct answer?

http://www.inspect-ny.com/exterior/v...b.htm#contents

Marcel

[homebild]

Mine was the correct answer relating to what the IRC 2003 and IECC 2003 required and did not require.

Doesn't mean that what I cited was the best practice.

The original question was whether or not the 2003 IRC or IECC required 'housewrap'.

The correct code answer is as I cited above.

[Marcel R. Cyr]

One should not forget that the IRC and relative Codes are the bare minimum and nothing to prevent from expecting better standard of quality installations.
The Codes are written to protect the Consumer with the bare requirements of Building.
We are not Code Enforcement Officers and should just note and report what we see as to the condition of the Building.
But for your information I have provided this below:

Vinyl siding is not waterproof, despite common misconceptions. Thanks to its overlapping profile, a standard interlocking wall of horizontal vinyl panels will effectively shed most rain and water away, providing superior water resistance. However, no vinyl siding is completely impervious to outside moisture from dampness rain or snow. For that reason, siding panels are manufactured with "weep holes" located at the bottom of each panel projection edge. These small but important outlets help channel away water that might find its way inside the siding wall through the panel seams and around moldings, windows, door and fixtures.

Weep holes also allow the infiltration of air, which also helps to dry out the inner surface of the siding while promoting evaporation of any remaining moisture. The application of house wrap and or insulation board also provides for a secondary defense against outside moisture that might penetrate the siding and come in contact with the original sheathing.

Look for weep holes in the butt, which allow any incidental moisture or water vapor to escape. At the same time, it’s important to keep rain from getting behind the siding. That means flashing must be correctly installed at windows, doors and gables. To address moisture retention that can lead to mold or rot, homes should be swaddled in a breathable house wrap.

Hope this helps.

Marcel

[Bruce A. King]

Many vinyl siding manuf's. are now requiring house wrap for warranty purposes. Requirement by manuf. makes it code right?

[Marcel R. Cyr]

Bruce, you are correct, it would make it a Manufacturers Code to protect their product and the Manufacturers product under that also.
Code as one looks at it is a minimum quality standard of practices in the Building Industry.

Marcel

[Joseph Hagarty, CMI]

Maybe not covered by code but required by the manufacturer.

http://www.vinylsiding.org/publicati...al_english.pdf

IMPORTANT NOTES

Weather Resistant Barrier
Vinyl siding has always been designed as an exterior cladding, not a weather resistant barrier.

Vinyl siding is designed to allow the material underneath it to breathe; therefore, it is not a watertight covering.

Because of its design and application, it provides a supplemental rain screen
that enhances the weather resistant barrier system by reducing the amount of water that reaches the underlying weather resistant barrier.
What Is a Weather Resistant Barrier System?
It is a system that includes water shedding materials
and water diversion materials. Weather resistant barrier systems commonly consist of a combination of exterior cladding, flashed wall openings and penetrations, weather resistant barrier material, and sheathing. Effective weather resistant barrier systems will shed the water initially, control moisture flow by capillary and diffusion action, and minimize absorption into the wall structure. The level of weather resistance required is determined by the applicable building code and structure
Best Practice:
To achieve designed performance, vinyl siding must be installed over a weather resistant barrier system that includes
1) a continuous weather resistant material and
2) properly integrated flashing around all penetrations and where vinyl siding interfaces with other building products such as brick, stone, or stucco.

Refer to the manufacturer’s installation manual for specific product applications and recommendations. Whichever product(s) you decide to use as part of a weather resistant barrier system, be certain the materials meet the applicable code by contacting the manufacturer of the weather resistant barrier material(s). Always consult the applicable building code for minimum weather barrier requirements in your area. Keep in mind that additional measures may provide better protection against water intrusion than the minimum requirements of the building code.

[homebild]

Please note that under the IRC 2003, no water resistive barrier was required under vinyl siding.

That changed under the 2006 IRC. A Water Resistive Barrier is now required by Code under vinyl siding. See Table R703.4.

Note also, however, that in Pennsylvania, vinyl and aluminum siding is exempt and excluded from complinace with the State Uniform Construction Code when installed on an existing residential or commercial structure....unless such installations are regulated by local amendment.

This means that vinyl and aluminum siding installations on existing buildings are completely unregulated in most of Pennsylvania.

See section 403.1 (b) (10) of the Pennsylvania Uniform Construction Code:

http://www.dli.state.pa.us/landi/cwp...q=211697#403.1

[homebild]

Originally Posted by bking

Many vinyl siding manuf's. are now requiring house wrap for warranty purposes. Requirement by manuf. makes it code right?

Not unless Code specifically overrules the maufacturer's installation instructions....

Most manufacturer's installation instruction defer to local code requirements.

[Joseph Hagarty, CMI]

Originally Posted by homebild

Not unless Code specifically overrules the maufacturer's installation instructions....

Most manufacturer's installation instruction defer to local code requirements.

As you suggest, the abscence of code does not negate the Manufacturer's recommendation.

The Manufacturer's requirement/recommendation then becomes the minimum standard if the Code does not address or falls short of reasonably expected.

Do you build in PA?

[homebild]

Builder and Code Inspector in Pennsylvania, Mr Haggarty.

Pennsylvania makes this 'ugly' by exempting vinyl and aluminum siding (on existing structures) from code compliance in the Commonwealth.

In such cases, the manufacturer's installation instruction would rule and it becomes an issue between the homeowner and the builder alone.

In other cases, the PA UCC would take precedence, and one would have the power of the law to assist in enforcing compliance.

In Pa, it becomes a municipality by municipality thing, and a manufacturer by manufacturer thing on existing structures.

All new construction siding in Pa as of 1-1-07 must have a water resistive barrier behind it...period.

PS: I am aquainted with one of your HouseMaster Inspectors in my region and we typically refer to one another.

I've been impressed with HouseMaster in regards to their training....