Your opinion needed

[John Onofrey]

building envelope

[Emmanuel J. Scanlan]

My vote is YES it is part of the "Building Envelope" and No it is not part of the "Building Thermal Envelope". It would depend on which "Envelope" you are referring to.

2003 IBC:

1403.2 Weather protection.
Exterior walls shall provide the building with a weather-resistant exterior wall envelope. The exterior wall envelope shall include flashing, as described in Section 1405.3. The exterior wall envelope shall be designed and constructed in such a manner as to prevent the accumulation of water within the wall assembly by providing a water-resistive barrier behind the exterior veneer, as described in Section 1404.2 and a means for draining water that enters the assembly to the exterior of the veneer, unless it is determined that penetration of water behind the veneer shall not be detrimental to the building performance. Protection against condensation in the exterior wall assembly shall be provided in accordance with the International Energy Conservation Code.

2003 IRC:

BUILDING THERMAL ENVELOPE. The basement walls, exterior walls, floor, roof and any other building element that enclose conditioned spaces.

CLADDING. The exterior materials that cover the surface of the building envelope that is directly loaded by the wind.

703.1 General.
Exterior walls shall provide the building with a weather-resistant exterior wall envelope. The exterior wall envelope shall include flashing as described in Section R703.8. The exterior wall envelope shall be designed and constructed in such a manner as to prevent the accumulation of water within the wall assembly by providing a water-resistive barrier behind the exterior veneer as required by Section R703.2.

703.8 Flashing.
Approved corrosion-resistive flashing shall be provided in the exterior wall envelope in such a manner as to prevent entry of water into the wall cavity or penetration of water to the building structural framing components. The flashing shall extend to the surface of the exterior wall finish and shall be installed to prevent water from reentering the exterior wall envelope. Approved corrosion-resistant flashings shall be installed at all of the following locations:

2003 International Energy Conservation Code:

N1102.1.10 Air leakage.
All joints, seams, penetrations; site-built windows, doors, and skylights; openings between window and door assemblies and their respective jambs and framing; and 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.

BUILDING ENVELOPE. The elements of a building which enclose conditioned spaces through which thermal energy is capable of being transferred to or from the exterior or to or from spaces exempted by the provisions of Section 101.2.1.

[rwand1]

The air gap between the exterior sheathing/moisture barrier and the brick veneer

Air gap (space), exterior sheating, moisture barrier is not integral to the brick veneer and vice versa.

BUILDING ENVELOPE. The elements of a building which enclose conditioned spaces through which thermal energy is capable of being transferred to or from the exterior or to or from spaces.

Conditioned spaces?

[Marcel R. Cyr]

Aside from locating a house out of the prevailing wind and providing roof overhangs, we cannot control the amount of wind-driven rain deposited on the exterior walls of a house, which is based on wind strength, wind direction, and rainfall intensity, Once the rain lands on the wall, its flow over the surface is affected by gravity, wind flow over the surface, and wall features. Fortunately we can control the wall features, making gravity work for us in carrying water where we want it to go.

In areas with up to 60 inches of annual rainfall the rain-scree system can be effective if designed and installed properly. In this approach an uninterrupted drainage plane with drainage space is maintained behind the outermost layers of the wall. As with the drain-screen system, the drainage plane can be constructed from overlapped layers of 30 lb. building paper or other material resistant to capillary action by water. At the bottom of the wall, properly designed apertures allow the rain to drain out of and away from the wall.

In areas with over 60 inches of annual rainfall the pressure-equalized rain-screen system is the best. In this approach, an uninterrupted drainage plane with drainage space is maintained behind the outermost layers of the wall. The air space must have enough venting to the exterior to equalize the pressure difference between the cavity and the exterior.

Eliminate water intrusion through the facade of the building and control it, you have now control over the thermal ambiance and intrusion. The building will actually dry from the exterior when it is controlled properly.

Hope this helps.

Marcel
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[gbeaumont]

Hi to all,

Just stolen from a very well respected source

Originally Posted by Joseph Lstiburek, B.A.Sc., M.Eng., Ph.D.,
P.Eng.

I love brick. I also hate brick. Let me tell you when I hate it. I hate it when it does not have a drainage plane behind it that is also an exterior vapor barrier. Wet brick exposed to the sun is like a moisture capacitor which discharges to the cold side. The cold side is the interior air conditioned space. I love brick when there is a vapor barrier acting as a drainage plane between the brick and the rest of the wall assembly. Most brick in the South is installed without functioning drainage planes and effective vapor barriers. If you are not going to use it right don't use it. When it is used right, it is the best exterior cladding system around (just don't paint it).

www.buildingscience.com

Regards

Gerry

[Carl A. Brown]

How do you think joe would feel about this brick job Gerry?
http://www.badstucco.com/bricks/bricks.htm

[rwand1]

National Research Council of Canada

http://irc.nrc-cnrc.gc.ca/pubs/cbd/cbd006_e.html

Cavity Walls
A special type of masonry wall construction, called "cavity wall", designed to prevent moisture penetration has been used extensively in some countries, particularly in Great Britain where severe exposure of buildings to rain is common. In recent years many buildings have been constructed in the United States of this type of wall and they have performed well against heavy rain. A cavity wall consists of two walls which are separated by a continuous vertical air space, but which are bonded together by metal ties. The principle of operation of a cavity wall is that in a storm rain may penetrate the outer part of the wall but it will then flow down its inside face without being able to cross the cavity to reach the inner wall.
The metal ties are usually designed with a "V" crimp in the middle so that water cannot pass along them to the interior. Water which flows down the cavity strikes a metal flashing at the base and is directed out of the wall through drains. In cavity wall construction, therefore, the brickwork of the outer "skin" of the wall is not relied upon to prevent moisture penetration. The rain which is expected to penetrate the wall is controlled in its movement and is directed out of the wall at the base. Careful construction of a cavity wall to avoid "bridging" of the cavity by mortar or other material which can transmit moisture, obviously is necessary for it to perform satisfactorily. Properly designed flashings over wall openings must be provided, as well as vertical diverter strips in the cavity at door and window jambs.

[cmccann]

Isn't there a who gives a s h i t thread somewhere for this?

[jclark1]

That's hilarious Chuck. And thanks for the support over the crap in the ethics thread.

[John Onofrey]

Originally Posted by cmccann

Isn't there a who gives a s h i t thread somewhere for this?

I brought it up because I was reporting on a condition where the weep holes were absent at the exterior limestone walls of a home I inspected. I was unsure if the air space behind the stone was considered part of the building envelope since it is outside of the exterior sheathing and moisture barrier. Actually, Manny's post covered the matter perfectly.

[lewens]

I see there is absolutly no significant change in Chuck's attitude. Sometimes I wonder how a person with that much hate can live with himself.
Larry

[jclark1]

Why soes this post never go away? No new post since 3-25 (until Larry's) but it consistently stays near the top of this board. Wierd........ I don't get it.

[Brian E. Kelly]

Originally Posted by jclark1

Why soes this post never go away? No new post since 3-25 (until Larry's) but it consistently stays near the top of this board. Wierd........ I don't get it.

James it is because the person that set up the original poll did not set a limit on the poll. So every time a person answers the poll the thread moves to the top, no matter how long the poll question has been there. Personally I like 10 day poll questions as that is 8 days longer than my poll question interest.

[Carl A. Brown]

Why aren't you guys sleeping?

[Brian E. Kelly]

Originally Posted by cbrown1

Why aren't you guys sleeping?

I am sleeping Carl.