Flashing windows with nail fins

[Bill Lacey]

WIndows that are covered by a porch roof (4-6 feet out from the house) probably would not need flashing, but it's a risky game to play. There's always the "what if" factor. I sell seven different brands of windows and none of them say anything about self flashing.

EDIT: How the hell did this become the first post? I'm fifth in line.

[Lavrans]

I am wondering how others deal with windows with nail fins. It seems that a lot of the manufacturers are backing off their claims that the windows could be considered self-flashing. I have always flashed them regardless of manufacturer claims, but still wonder what you do, and if you rely on the window to self-flash, how have they been doing?

Lav

[Toolwhore]

Lav;

There isn't, and never has been, a self flashing window. Read this; JLC, June 2005, Flashing a Flanged Window.

[Lavrans]

Tom- I know there has never been a self flashing window, but, for example, I know some people who think that vinyl windows with nail flanges don't need to be flashed. I may be imagining this, but I'm pretty sure I have read instruction books that claimed flashing wasn't needed under certain conditions. Regardless, like I said, I don't think any should be installed w/o flashing. I am just wondering who doesn't, and how their callbacks have been.

[Vinnie]

The fins or windows may stop the water from making it to the ground. I think that if we should stop the splash of the water. After that, will not have the water fighting to get in to the homes. So If the windows do not splash than the water can drop away from the window.

[davenorthup]

Originally Posted by Lavrans

Tom- I know there has never been a self flashing window, but, for example, I know some people who think that vinyl windows with nail flanges don't need to be flashed. I may be imagining this, but I'm pretty sure I have read instruction books that claimed flashing wasn't needed under certain conditions. Regardless, like I said, I don't think any should be installed w/o flashing. I am just wondering who doesn't, and how their callbacks have been.

I am willing no one here does... :) (not flash windows that is) I think Bill R. would come over and smack anyone if they did.

I am re-siding a house that had absolutely no flashing what so ever. Amazingly enough the house is dry except one window. The original builder really screwed these people, and no flashing was a minor issue. This re-side has turned into a big job. Ok with me.

Bill - I hope this will replace you as first post in the weird forum vortex...

[Bill Robinson]

2003 IRC

703.8 Approved corrosion-resistant flashings shall be installed....
1. At top of windows EXCEPT that self flashing windows having a continuous lap of not less than 1 1/8" over the sheathing including corners do not require additional flashing. jamb flashing may be omitted when approved by the building official.

This is in the 2003 IRC.
the 2006 will read differently.
I would hope that you would follow ASTM E 2112 and use 9" wide, 24 hour minimum water resistance continuously labeled flashing.
If you don't, please let me know where you are building so I can do some more consulting for construction defects. Bring your pink slips cause I will be collecting them>;}

Bill R

[Adam Smith]

[QUOTE=Lavrans]I am wondering how others deal with windows with nail fins.


Grace Vycor...I hope this isn't a trick question!

[Finnegan]

I would flash a window even under a deep overhang. You never know when someone is going to hose down or pressure wash that wall. The flashing should also cut down on air infiltration.

[Lavrans]

So, no one here would skip flashing. I haven't worked with anyone who would skip flashing. I can't find anyone who will admit to skipping flashing. So why do I keep running into unflashed windows?

You've got to admit that job security can be a depressing thing.

Lav

[Bill Lacey]

Maybe it's the people who have a good relationship with the inspector, and they are allowed to leave out these "minor details" just to save a buck.

[Stuccoman]

Each window that has trim around it needs three peices of metal z flashing with proper laping of the moisture barriers along with backer rod and sealant on the sides.
www.badstucco.com/properflash/properflash.html
1.Under the nail fin at the bottom under the trim and out over the sideing.
2. At the head of the window out to the sides of the trim not justto the corners of the window.
3. At the top of the trim above the head of the window.

[Finnegan]

I have also seen enough unflashed windows. I think the folks who spend time on this site are interested in finding the best construction practices and are probably not likely to do things obviously wrong. However, I am sure that there are enough of others out there willing to cut a corner.

[Sweep8]

Here is post from another site

W R Grace products work well for sill and jamb flashing but can be a problem when used to seal the fin-to-frame seam of a clad window because it puts the edge of the asphalt membrane well into the trim-to-frame joint where it can come in contact with the cladding/trim sealant. Many popular modern sealants contain plasticizers that can soften the asphalt, even liquify it so that it drains out of the joint at a lower point.

Butyl (StraightFlash, SmartFlash) would be a better choice if you need to seal the fin on a clad nail-fin window but you should always put some beads of the sealant you want to use on the sticky side of the flashing a week in advance to see if one reacts with the other.

I was taught that butyl should be compressed between two non-pourous (metal or glass) materials but that was before pressure-sensitive adhesive tapes were marketed as permanent seals. It is still true, however, that the non-pourous surfaces must be cleaned with a solvent to remove anything oily, even fingerprints (gloves required).

All self-adhering flashing must be rolled with a small rolling tool, not just to get air out but to insure the initial seal. A little friction to warm the tape can sometines help as well on pourous surfaces. For flexible self-adhering flashings the AAMA sets the minimum overlap of a seam or joint at 2 inches. Unfortunately that is not possible at a nail-fin seam without exposing the flashing.

Here are some of the original references:
http://www.wconline.com/CDA/Archive/...00f932a8c0____

http://www.fortifiber.com/fortifacts...patibility.htm

http://www.aamanet.org/mp/XXX-XX_D2b_4-4-06.pdf

[Stuccoman]

This is how not to flash windows!

http://www.badstucco.com/ff.htm