https://www.jlconline.com/how-to/exteriors/rethinking-window-flashing_o

https://www.youtube.com/watch?v=iyFMWEMwbsQ

https://www.youtube.com/watch?v=cVckyMUJHQI

https://www.youtube.com/watch?v=BCkZXAuxY74

https://www.finehomebuilding.com/2015/07/11/watertight-window-flashing

https://www.finehomebuilding.com/2008/07/03/installing-and-flashing-windows-correctly

Specific how to depends on your wall assembly and the window.

Pictures will help with suggestions.

Every window manufacturer will have installation instructions as well.

It could be done without removing, or maybe loosening up the bottom but there is not much room if the window is installed and could be difficult to determine what happens to the Tyvek or if gets installed underneath it properly . Don’t think they would need new Tuvek if removed it could just be taped .

I gotta admit that I have done many things twice before. Big thing is how they correct and if they learn.

Most window installations are poor, even on expensive homes. Windows are major sources of water leaks and air leaks. The more exposure to wind blown rain, the more important to follow best practices. What brand and do you have any pictures from inside or outside before siding and drywall?

Good links PPF but you missed one of the best window flashing articles.. ;)

Yes, water is the mortal enemy of newer homes, it gets everywhere and does bad things.

Is this the first house your builder has constructed?

Save the window installation brochure (or Google it and print one) for him and for your records. Watch carefully.

This builder has been in business 30 years. However, apparently he doesn't like to read the installation instructions. He didn't do a 6" overlap of the Tyvek seams. He also didn't run the Tyvek over the flashing at the top of the window. He installed the flashing on top of the Tyvek and then taped it.

Since he didn't overlap Tyvek seams 6", should we expect him to remove all the siding an re-Tyvek the entire house? I'm guessing he overlapped 2-3" (we'll be able to tell once the siding is removed when we redo the window flashing).

Tell him to you tube it if he can’t read.

And he’s still on the job?

This builder has been in business 30 years. However, apparently he doesn't like to read the installation instructions.

Real men don't need no damn Building Codes!

window installations are poor, even on expensive homes

For two years, I watched the housewrap on this $20+million home bake in the sun.

Excepts-

Width plus 12. Cut a piece of flashing tape 12 in. longer than the width of the opening, which allows 6 in. of tape to extend up each side

Continuous outside corners. You can buy flashing tapes made for curves, but they’re expensive. Protecto Wrap tape is far more affordable and has enough flexibility to be stretched down onto the sheathing, where I tack it in place with button-cap nails.

Keep the transition tight. Use a rafter square to press the tape tightly into the corners where the sill meets the sides of the rough opening, eliminating bubbles under the tape that are vulnerable to puncturing.

You buy the supplies. Have them on site.

If I were you, I’d be having serious thoughts about my choice of contractor. It seems to me that he’s taken shortcuts with window installation and siding installation. If he’s installed the siding correctly, he should have used Hardie trim around the windows. Windows get broken from baseballs, hailstones, etc. had he done this and then installed the siding to the trim, replacing the z flashing, taping it correctly, removing and reinstalling the window if necessary, wouldn’t be a tenth of the effort and cost that is now going to be incurred. Your contractor sounds like a hack. Sorry to be blunt, but a contractor who can’t read instructions should not be in business without supervision.

We are doing hardie board and batten siding. So the siding panels are 4'x10'. Its not lap siding. The install instructions for the vertical siding panels are a little different. His main mistakes are he installed the wrong size metal flashing and he also installed the flashing over the Tyvek instead of behind the Tyvek. Because it is large siding panels (not lap siding), it is much more difficult to fix and you have to remove much more of the siding to fix it (entire panels).

I do regret my choice of contractor but I am literally stuck with him. Other contractors in my area will not take over a job midway through. I think I need to work with my contractor to try to resolve the issues.

we are in contract with this builder. It is not easy to get out of it. We wish we had hired a different contractor but we are stuck with him and hopefully he will be able to fix his mistakes. I think where i live a lot of contractors build at a lower quality level because they can get away with it. This is the SF Bay Area - we don't get a lot of weather so even poorly flashed houses probably perform ok over time. Also, there is huge demand so its about impossible to get a top quality contractor unless you work at Apple and have millions of dollars at your disposal.

you watched them do it and then Complained afterwards?

metal flashing is not needed in the sill.

Metal is not needed on the sill. This is part of the problem with youtube, there are far too many guys that make video’s that are either unrealistic or complete overkill. In fact, i would venture to guess that most of those guys in those installation video’s dont completely follow their own advice when doing an install. if a customer tells me to follow xyz video on youtube, i politely tell them to find another contractor and walk away with no stress and no aggrevation. I will let someone else deal with that bs.

I get More confused the more you explain. If you wanted done a certain way and you were there instructing then how to do it and they did a different way and you let it slide I’d say you were equally at fault. Sometimes home owners suck too.

What metal goes around the window ??! What are you talking about ? Why are you looking at on line video’s? Your installers are tolerating you doing that?

I have to agree with the other pros, I'm not sure what you are describing @quantifiable. More importantly, if there is something to take away from this, its to have these conversations prior to hiring the contractor, AND getting it in writing. There is an extremely broad range of ways to install a window and still be "correct", starting at something that barely passes industry standards and ending at best practices with the latest, greatest, and most comprehensive procedures and materials. Unfortunately in many cases, homeowners want to pay the price on one end, yet get the detail and quality from the other end.... and FWIW, I'm not saying that is the case here, but its a pretty common thing.

My windows have copper sill pans that have lasted for 125 years. It was the standard until the 60's.

It was the change from factory installed casing trim to nailing-fins with field applied casing trim that caused wide spread confusion. To limit their liability the manufacturers of the windows, the flashings, the weather barrier and the exterior claddings each published installation instructions with little or no coordination. This might have worked if any of them knew anything about exterior envelope waterproofing.

I have always followed the advice of WR Grace which changed its mane to Grace Products and then to GCP Technologies. If you were unsure of a detail you could just call them and they would explain it to you. Many of their materials have been copied by others so the details don't depend on using their products anymore.

When the head trim was factory installed, the cap flashing was placed over the top of the head trim. Today there are competing opinions about where flashing belongs on a nail-fin window. Some say flashing tape is adequate. Others say there should be a "Rigid Head Flashing" over the top nail-fin and a drip cap over the head trim. Others say to use one or the other but not both. I miss the old windows.

Good luck.

The thread is NOT about how to properly flash a window. It's about GC not knowing how to do it.

Oh fck, OP, if you think you are having problems now...

Hmmm, torn out a few old windows before and have not ran across one copper sill pan. Perhaps standard in your area. All the old windows I remove would be lucky to have a piece of tarpaper In the sill.

Until WR Grace offered its Bituthene self-adhering flexible flashing in 1965 the only way to flash a window sill was with a metal pan. Since residential building codes at that time were rare and subsequently slow to address waterproofing issues I'm sure there are a lot of windows that effectively had no flashing. Here is the ASTM E2112, Standard Practice for Installation of Exterior Windows, Doors, and Skylights recommended details.

The biggest flaw in that standard is it recommends too many methods for flashing a window.

There is no way to address the contractor's flashing method without a photo and since it occurred 2 year ago this discussion can only be an academic exercise regarding flashing methods.

I wonder if by this time the OP has had any problems with the construction now that they have presumably moved in?

HomeSealed Exteriors, LLC It's really hard to describe without photos. I wish Albert's Roofing Web Site was still up. He did a great job of explaining it.

Here's a pretty common method of flashing @quantifiable, not sure how close this looks to your installation. Feel free to post pics if you have any. When trim boards are used, a metal head flashing is often added over that in addition to the diagram, although some guys will add it right above the window... Also, I do agree with your comment on hacks trying to underbid one another, although keep in mind that the willingness (or lack thereof in many cases) of the consumer to pay for quality is a large driving factor there as well.

@res2architect , I'd have to agree with toddinmn that perhaps the metal sill pan was a regional thing. Not questioning the validity of applicable standard at the time, just saying that its not something that is seen, at least not in my area. Having removed thousands of pre-1965 windows, the next time that I see a metal sill pan will be the first.