R703.8 Window flashing no longer required

[mark handler]

Not enough blood flowing to the brain?

try standing on your head

 

[peach]

show me a real "self flashing" window... I believe it came out of the IRC in 2006

 

[GHRoberts]

It is difficult to argue that flashing is needed.

I have seen houses where despite there being no flashing, there is no weather damage to the structure.

I have seen houses where despite careful flashing there is weather damage to the structure.

 

[Robert Ellenberg]

Opps!--I opened up my 2003 IRC and quoted from it where flanged windows were considered self flashing. It was taken out in 2006.

 

[Robert Ellenberg]

I reread Jar's original post and this is NOT a big deal. Vinyl siding can be unzipped, fasteners removed and the material reinstalled.

 

[conarb]

Opps!--I opened up my 2003 IRC and quoted from it where flanged windows were considered self flashing. It was taken out in 2006.

Could you copy and paste that? We have never been on the IRC (will be on the 1st) but I recall the building inspectors talking about that on the old Bulletin Board, as I recall it didn't say "flanged windows were considered self flashing", but as I recall it did reference "self flashing" windows, but again no manufacturer has ever made a "self-flashing window".

 

[Sandman]

There is no such thing as a "self flashing window." Does not exist.

WINDOW INSTALLATION

"Section R612.1 of the 2009 IRC requires that windows and doors be installed in accordance with the fenestration manufacturers’ installation instruction and flashed in accordance with Section R703.8. Section 1405.4 of the 2009 IBC requires window openings to be flashed.

Section R703.8 of the 2009 IRC gives more specific provisions for the installation of flashing around the window. It requires that flashing be installed in shingle-fashion in such a manner as to prevent entry of water into the wall cavity or penetration of water to the building structural framing components, and that the flashing is to extend to the surface of the exterior wall finish or to the water-resistive barrier for subsequent drainage.

New in the 2009 IRC is a reference to an AAMA standard for self adhered flashing. Section 703.8 of the 2009 IRC requires self adhered membranes used as flashing to comply with AAMA 711."

http://www.windowanddoor.com/article/codes-standards/international-code-requirements-windows-doors

 

[RJJ]

Gee! I thought the avatar was the content! I was trying to figure out haw one would flash that!

 

[Robert Ellenberg]

From the 2003 IRC

"R703.8 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:

1. At top of all exterior window and door openings in such a manner as to be leakproof, except that self-flashing windows having a continuous lap of not less than 1 1/8 inches (28 mm) over the sheathing material around the perimeter of the opening, including corners, do not require additional flashing; jamb flashing may also be omitted when specifically approved by the building official."

The quote from the 2009, "Section R703.8 of the 2009 IRC gives more specific provisions for the installation of flashing around the window. It requires that flashing be installed in shingle-fashion in such a manner as to prevent entry of water into the wall cavity or penetration of water to the building structural framing components, and that the flashing is to extend to the surface of the exterior wall finish or to the water-resistive barrier for subsequent drainage. ", can be interpreted to mean you can tape seal the flanges to the WRB with the top of the WRB coming over the flange and no further flashing is required to bring it out to the face of the siding. However, the very first word in R703.8 is key, "approved". If you don't like it done with just a flap of WRB, you can require it to to be a metal piece of flashing.

 

[KZQuixote]

Robert said: "If you don't like it done with just a flap of WRB, you can require it to to be a metal piece of flashing."

Not perzactly!! No manufacturer's instructions will accept the simple lapping of the WRB over the nail fin at the head as acceptable installation practice. The American Architectural Manufacturer's Association has adopted 9" as the standard for the width of window flashings, flexible or other wise. Recently AAMA has struggled with adopting a standard for self adhered flashings. How wide is wide enough? The answer is follow the manufacturer's installation instructions. The correct practice at the head of the window is to apply a nine inch wide flexible flashing adhered with sealant across the head of the window. over the nailing flange, and then to lap the WRB over that strip of flashing and to seal any cuts that were necessary to lift the lap with "sheathing tape".

Bill

 

[Robert Ellenberg]

Bill,

I don't disagree that you should follow the manufacturers instructions but it is not that simple. My prior post was strictly from a code standpoint related to R703.8.

Unless I am missing a part of the code (and let me know if I am), it says 2 things specifically that could be in conflict: (1) "approved" strictly means acceptable to the building official. (2) The window flashing section does NOT specifiy referring to the manufacturers installation instructions in R703.8 but says the flashing must be done a certain way with a material that is "approved" and then you go to R613.1 that says you shall install in accordance with the manufacturer's written installation instructions. What if the manufactuer doesn't even give specs for your application? What if the inspector says he wants it done a different way? Try to look up Pella's instructions for installing with a layer of foam with cement board siding (it doesn't exist and several communications with tech. support at Pella have failed to produce anything); then look at Hardi's siding sheet on window install guidelines which are different and don't match up with how Pella says it should be done with siding. I am using the guidelines from the US Dept of Energy written by the Building Science Corp. in MA as they are probably the best practice for foam sheathed walls and proper window head flashing. But if a BO challenged me on it, he would be right in saying it didn't meet "code" since it wasn't according to the window manufacturer. And if the cement board siding were to fail prematurely for any other reason, they could claim I didn't follow their instructions and void the warranty.

Sometimes I think ignorance of all these issues would be bliss.

 

[KZQuixote]

Hi Robert,

Sorry, but I wasn't very clear with my reference to manufacturer's instructions. I was speaking only to how wide self adhered flashing systems must be. If a manufacturer promulgates an installation method that says 6" wide peel and stick flashing is acceptable then AAMA is OK with that width. But lacking any specific statement from a manufacturer 9" is what most any other standard will ask for. AAMA RLC-1 2008, CAWM-95, ASTM-2112.

Regarding the foam board, I can only hope that it is covered with a WRB and if it is the technique would be the same as if it were over OSB sheathing.

Do you see a lot of exterior foam insulation board? I don't believe that stuff breathes very well.

Regards

Bill

 

[Yankee]

Hi Robert,Regarding the foam board, I can only hope that it is covered with a WRB and if it is the technique would be the same as if it were over OSB sheathing.

Do you see a lot of exterior foam insulation board? I don't believe that stuff breathes very well.

Regards

Bill

Most foam boards I've seen have a vapor perm higher than plywood or sheet rock. The foil covering will lower the lower perm.

 

[brudgers]

It is difficult to argue that flashing is needed.I have seen houses where despite there being no flashing, there is no weather damage to the structure.

I have seen houses where despite careful flashing there is weather damage to the structure.

I've seen buildings in hurricane prone regions where the rafters are attached by three toenails...before a hurricane.

One can very carefully install flashing incorrectly.

Nobody ever says, "I'd rather have a few more leaks than spend $300."

 

[Robert Ellenberg]

Bill,

I try to keep up with what the building engineers who are monitoring and testing publish and they disagee on some things. But all agree an exterior layer of foam greatly reduces the thermal bridging of the studs and is important in most climates. They all also say you must have a rain screed or drainage plane on the exterior so that most all of the water that gets past the exterior cladding can drain rather than soak into the wall. They also do not use an interior vapor barrier so the moisture that gets in the wall can dry to the interior. The exterior layer of foam complicates fastenings of sidings if it is over 1" thick which it must be in climate zones 6 and above with the 2009 IRC (maybe the 2006 too, can't remember). They don't require the exterior layer but if you do it, the colder the climate the thicker it must be to prevent condensation inside the wall.

 

[conarb]

Be careful putting styrofoam on buildings, be aware that Lstiburek and company have no respect for and ignore building codes, foams are the stuff that killed our firefighter friends in the Rhode Island Station fire and the South Carolina sofa warehouse fire. Our code limits it to ½" on exterior walls. I've seen it use with that 5/8" yellow Dens Glass gypsum material covering it.

2603.4.1.10 Siding backer board. Foam plastic insulation of not more than 2,000 British thermal units per square feet (Btu/sq. ft.) (22.7 MJ/m2) as determined by NFPA 259 shall be permitted as a siding backer board with a maximum thickness of 0.5 inch (12.7 rom), provided it is separated from the interior of the building by not less than 2 inches (51 mm) of mineral fiber insulation or equivalent or where applied as insulation with re-siding over existing wall construction.

Also be aware that they are New England cold climate gurus, foams can't be used anywhere near the ground in most of the United States.

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[DRP]

I'm not seeing foam prohibited by code...

 

[Sandman]

There is no code prohibition for insulating foam. Just another ConArb declaration "OMG the sky is falling and we are all going to die!" based on frivolous lawsuits and unsubstantiated claims. However, this is a complicated subject and the easy answer is that the manufacturer’s installation instructions and the code are the MINIMUM requirements while the recommendations from building scientists exceed the minimum. If the contractor and owner agree on spending more time and money to keep moisture out, then inspectors need to recognize the effort.

 

[conarb]

There is no code prohibition for insulating foam.

I guess I posted the map before I posted the IBC prohibition.

2603.8 Protection against termites. In areas where the probability of termite infestation is very heavy in accordance with Figure 2603.8, extruded and expanded polystyrene, polyisocyanurate and other foam plastics shall not be installed on the exterior face or under interior or exterior foundation walls or slab foundations located below grade. The clearance between foam plastics installed above grade and exposed earth shall be at least 6 inches (152 mm).Exceptions:

1. Buildings where the structural members of walls, floors, ceilings and roofs are entirely of noncombustible materials or preservative-treated wood.

2. An approved method of protecting the foam plastic and structure from subterranean termite damage is provided.

3. On the interior side of basement walls.

Furthermore, Environmentalists are banning the stuff worldwide for clogging up the oceans killing the fish and birds.

 

[DRP]

So... it is allowed beneath siding which IIRC must be 8" above grade?

 

[SCBO1]

I'd like to get back to the inspection process:

1) Permit for vinyl siding, required?

2) How many inspections would have to be done on a vinyl siding job?

3) Like with hard board type sidings you can inspect the nail pattern if not blind nailed, is the vinyl siding nailing to be inspected?

4) Is there a pre-inspection done to determine if the existing material can except the vinyl siding application?

5) Fan-fold insulation, does it have to be inspected?

Have'nt seen to many vinyl jobs where the installers put the house numbers back!

Inquiring minds need to know!

 

[fatboy]

We just do a final inspection. Typical violation.....failure to use an extension ring on lighting and receptacle outlet boxes. Tipoff......the installers use deck srews to re-attach lights and trim.

 

[SCBO1]

fatboy,

I've seen drywall screws to re-attach lights, mainly lack of silicone being used or too much to avoid proper installation!

 

[Jobsaver]

I believe the intent of the code to require flashing above windows is to keep moisture, resulting primarily from precipitation, on the outside of the building envelope. Why is there no exception for proximity to eaves? Under porches?