
Q&A Spotlight

My Windows Were Installed Incorrectly. Now What?

Should the windows be removed and reinstalled?

This window was not installed according to the manufacturer's instructions. The homeowner wonders whether he should insist that the windows be removed and reinstalled. [Photo credit: Brian]

Brian is building a new house in New Jersey and has selected Andersen 400 Series windows. So far, so good. The problem is how the windows have been installed by Brian’s builder.

Many of the manufacturer’s installing instructions have been ignored, Brian writes in a Q&A post. The contractor used no caulk, chose Tyvek housewrap tape instead of flashing tape, and failed to overlap the Tyvek by at least 6 inches, as required by the instructions.

“It looks like they lined the rough openings with Tyvek and a bit of Vycor Plus flashing at the botton only, then installed the windows without caulk, then installed a layer of Tyvek across the tops of the windows, and over the top nailing flange, then taped the flanges with Tyvek housewrap tape,” he says.

In an earlier post on the same topic, Brian outlined what he believed were the shortcomings in the builder’s installation methods. When he asked around for advice, the replies were not encouraging: One certified Andersen installer told him he was convinced the windows will leak.

“My builder says the windows are fine,” he wrote. “They have installed thousands of them like this, he says, and never had a problem. He very much wants me to drop the subject.”

What’s the best course for Brian to take now? Should he insist that the windows be redone? “I am prepared to redo,” he says, “but given the cost I would like to be certain that it’s really necessary.”

Brian’s painful predicament is where this Q&A Spotlight begins.

It shouldn’t cost you a dime

The building code requires that all materials be installed according to the manufacturer’s instructions, GBA editor Martin Holladay says, so the cost to Brian should be zero.

“The cost to fix this is the responsibility of the contractor who made the errors,” Holladay writes.

Maybe so, replies John Clark, but in demanding that the builder remove the windows and put them back in correctly he runs the risk of future problems.

“My concern would be causing ill will with the builder,” Clark says. “For example, is he going to make up for the lost time in future phases of the build? In one sense you really are at the mercy of the builder, the clock is ticking and interest is accruing.”

Causing offense may be of secondary importance, Brian says, because he’s decided to take over the project himself. His biggest concern at the moment is understanding the magnitude of the risk he runs by not forcing the builder to redo everything.

Visit other job sites and compare

Walter Ahlgrim suggests that before Brian insist that the windows be redone, he take a tour of nearby job sites for a look at how other builders are installing windows.

“Before you complain to the builder, visit a few other builders’ work sites,” he says. “My guess is you will find your house is much better than what you are likely to find in the wild.”

Does that mean most new construction doesn’t meet code? Brian asks.

“I don’t think it’s OK at any budget level to skip less than 1% in cost and effort needed to make a structure excellent, and now, instead, it is totally questionable and at risk,” Brian replies.

He could offer to split the cost

Brian is right not to want to alienate the builder so early in the process, Akos says. There’s still a long way to go before the house is complete.

His suggestion is to offer to pay for some of the materials — such as flashing tape and caulk — that would be needed to do the job correctly and then splitting the cost of labor.

“In the future, I would recommend agreeing on these kinds of details ahead of time to save time,” Akos adds. “It might seem infantilizing to go over details they should know, but it at least sets the expectation of how you want the job done. This does mean a bit of research on your end and not going overboard; you don’t want to sound like a Mike Holmes type of ass.

“Details are important to get right,” he continues. “They can also suck up a huge amount of time, so it is important to talk about it.”

He adds that the installation is probably better than many of the subdivision jobs he sees. “Sometimes it is worth a bit of effort and cost to move things along and actually finish the house,” he says.

Detailed drawings are not for routine work

Malcolm Taylor disagrees that all of this should be identified in drawing details.

“On the drawings I do, the details are for things that are out of the ordinary or particularly important,” he says. “In the absence of a specific detail, the default is to follow all pertinent codes and standards — and the manufacturer’s instructions. That’s typically spelled out in a prominent note on the first page of the drawings.”

Taylor adds that Brian isn’t asking for anything in particular — other than getting the windows installed as per the building code.

A massive waste of time and materials

The house is now trimmed inside and out, Brian adds, and all of that work will have to be ripped out and discarded.

“How stupid!” he says. “It is a colossal waste of resources, and a colossal act of disrespect to a homeowner to build a house in this fashion, precisely because it cannot be easily or inexpensively fixed, and now the life and performance of the whole structure is compromised.”

The builder had assured him that he had years of experience and would install windows according to code. Nor was there anything especially unusual about the job.

“It turns out that not only did they not follow the fairly straightforward manufacturer’s instructions,” Brian says, “they did not follow any of the standard advice given in the multitude of articles and videos available. No caulk was used. No flashing tape. They stupidly skipped 5 minutes of work per window and $500 total of materials on a job that should obviously be done right to protect the total investment in the structure.”

Our expert’s opinion

GBA technical director Peter Yost suggests that Brian conduct a spray test with a garden hose, something along the lines of the , to identify any windows that might be leaking.

Later, he adds these comments:

Brian asks a really tough question: Will these windows leak? It’s a difficult question to answer without more information about exposure, the region, the site, and the use of design features that shelter windows from weather exposure. Brian was kind enough to send me many more photos of his home and we talked at length on the phone.

We started by reviewing and agreeing on just how far off the mark the builder window installation was from the . Here’s a summary of how well the builder did on that count:

  1. Install WRB before the window? No.
  2. Full wrap of rough jambs? No.
  3. Sill pan flashing? No. (See the photo below.)
  4. Weatherlap the drip cap to tape and WRB? No.
  5. Proper flange-taping sequence and lengths? No.
  6. Weatherlap WRB to window flashing (head and sill)? No.

And the best practice of installing sloped or back-dammed sill pan flashing is not part of the window installations.

A lack of sill pan flashing is one of several installation errors on these windows.

In addition, there are shortcomings in the installation of the WRB. Key  elements of the were not followed. Those errors include:

  1. Fasteners were staples rather than cap nails. The staples that the builder used were not “equivalent” fasteners.
  2. Many vertical and horizontal joints were not taped.
  3. Not all laps were overlapped with the minimum 6 inches.

Now for the siding. The manufacturer, James Hardie, publishes a to help installers get the installation right. In this case, several points were ignored.

  1. There is an improper gap between the siding and a perpendicular roof.
  2. The siding was cut tight to the window head trim and caulked instead of leaving a 1/4-inch gap.
  3. The cut ends of the siding are not treated or sealed.

The bottom line

The key question is whether the windows will leak. Here’s my take:

  1. Site: Brian’s home is not anywhere near a coast, nor is it on a lake or other large open area. (Brian estimates the “fetch” around his home to be between 50 and 150 feet.) This qualifies in my book as a fairly sheltered site.
  2. Design: Some windows are quite sheltered by eave and rake overhangs and porch roofs. But some windows are quite exposed, and more than one window is located very close to a wall/side roof connection. (See the photo below.)
  3. Flashing and gutters: The entire home is guttered, but at all sidewall-to-roof connections, there are no kickout flashings.
  4. Exposed flashing protection: Each window is missing a window cap; there is a half-round projection in the profile of each Azek head trim but no separate window cap protecting the head of the window or the head of the trim. The head of every window should pull that water load away from the window just below it.
  5. Drainage at the cladding level: The course of lap siding just above each window is installed tight to the window head trim and Brian believes this joint is also caulked (essentially, a face-sealed approach at the cladding level). A face-sealed approach in any area with greater than 20 inches of precipitation a year (all of New Jersey is much greater than this) is not matching protection to risk.

Brian had a lot of detailed photos of these installation shortcomings, but he thought that publishing them would risk his  anonymity. The photos certainly confirmed serious issues regarding window, WRB, and cladding installations.

Some windows are located in areas that are especially vulnerable. The builder did not include any kickout flashing on the roof above this window.

Some of Brian’s windows are going to leak — some much sooner than others. Brian is not interested in trying to get his builder to protect him for just the 10 lost years of the voided guarantee from the window manufacturer. He wants windows that won’t leak for their entire service life. Difficult as it may be on his relationship with his builder, Brian will need to insist that his builder reinstall at least all of the windows that are more exposed to the weather. That includes windows on the prevailing-wind side of his home, and the first-floor windows on gable ends. Even if kickout flashings are installed at all sidewall/roof connections, I would insist that these windows be reinstalled as well.

As Brian has expressed, what a shame that an otherwise quality builder does not understand the primary importance of bulk water management. Banking on “been doing windows like this for years” rather than meeting even the manufacturer’s installation requirements is inappropriately placing experience — without the support of actually knowing how his windows do over time —  higher than physics and building science.


  1. Hugh Weisman | | #1

    Given all of Brian's pictures at various stages of the window installation, it would seem to me that Brian was interested (perhaps concerned) about the installation early on. Was this conveyed to the builder before the installation was completed? Did the builder barge ahead despite the concern? My point is that the builder may have brought this on himself by pushing ahead even after the problem was brought to his attention.. If this was my house, I would insist on all the windows being re-installed. And depending on my feeling about the builder and the degree I thought he made an honest mistake vs. willful flouting of proper methods, I might offer to share some of the cost.

  2. John Clark | | #2

    True story about kick-out flashing. My community just went through a re-roof and a neighbor had a roof-wall intersection where the gutter had no kick-out flashing and consequently water left a 6 ft long stain on the brick wall beneath it. During my chat with the foreman who was managing the re-roof he assured me that kick-out flashing was going to be installed along with new gutters.

    End result, kick-out flashing has not be installed at any roof-wall intersections. I guess it's just too expensive to retrofit after the fact because each unit has 2-3 roof-wall intersections and there are over 150 units.

  3. Josh Durston | | #3

    IMHO, Get it redone, even if it costs you something.
    Personally I couldn't be happy with the house knowing that the windows were installed that way. Even if they don't leak, it's still not right. You'll always be wondering if your walls are rotting from the inside. They didn't even get the little bit of Vycor flashing installed flat and parallel. Looks like they got a monkey to do it.

    -Benjamin Franklin

  4. Walter Ahlgrim | | #4

    It has been almost 6 weeks since the home owner brought his concerns to the builder’s attention.

    6 weeks is an eternity on a work site, what happened?

    Has all work stopped or did they plow ahead?


  5. Scott Wilson | | #5

    If you have a documented list of omissions or errors regarding the installation of the windows (according to either the instructions from the window manufacturer or local building codes) and the builder insists that what he did is acceptable and "the way he's done it for years and there's never been a problem" then sum up what you wanted done and what he actually did do when installing the windows and have him sign it. Turn it into a legal contract stating that if his changes to the recommended installation guidelines results in future damage to the home (from leaky windows or missing flashing) then he has to pay for it. See if legally he will stand behind his work.

    On a separate point, if you had concerns about whether he was going to follow the proper instructions for installing the window (and I suspect that the reasons you had concerns was because of concerns you had seeing him do previous work on the house - either framing, insulation or mechanicals, etc) then you should have been on site and watched him completely install one window. Video tape the install to prove what he did. If it's not what you want then tell him that's not acceptable and fix that one window before letting him install the rest.

  6. Lee Newton | | #6

    I can't believe a builder would do work like this, ok maybe I can, but I'm really speechless that there is any question about pursuing a remedy. Most states would specify that the contractor is vicariously liable for failure to perform pursuant to prevailing building codes/manufacturer's guidelines. Doesn't matter if it was discovered during the build or up to 18 months after completion (in Michigan). If there is any doubt, show the builder this article and the comments, if he can read.

    1. John Clark | | #7

      How does that liability work if the building inspector signed off on the work?

      1. Malcolm Taylor | | #8


        In Canada the case law suggests municipalities do not have Strict Liability. That is, they are only responsible to ensure the building will not be unsafe for the occupants. They are not expected to make sure it conforms exactly to the specifications on the plans, or is built in conformance with manufacturer's instructions.

        In the preamble to our code it says that ensuring a building meets the code is the owner's responsibility.

      2. Scott Wilson Sr | | #9

        Building inspector has no liability.

        1. Malcolm Taylor | | #11

          It's bit more nuanced here:

          "... goes on to state that inspector is not required to discover every latent defect or failure to meet the building code. Rather, the inspector is expected to act reasonably to detect defects and order them remedied (this includes latent defects). Although the municipality was ultimately found liable because the defect was a health and safety risk, the case suggests that the duty of care is limited to matters of health and safety. "

  7. dangrs1 | | #10

    Been through this. I was my own general on my personal house. I used an insulated vinyl siding. The installer assured me he had used the product before. I had used the same siding on a couple jobs I did myself but didn't have time to do this one. First the guy shows up a week early and starts the job without telling me. I didn't have all my outlets and lighting in place yet. Then I see the workers breaking the insulation off to make it easier to get it behind the J channel. I stopped the job and had him tear off the entire back of the house. He left and I didn't pay him and never heard from him again.
    That said if you haven't paid him yet I would tell him make it right or leave.
    Window and door manufacturers are low quality when it comes to foolproof installation. With all the advances in engineering you would think there would be something better than tape and caulk that will dry out, shrink, or fall off in the future. Think a submarine door.

  8. User avater
    Leigha Dickens | | #12

    I appreciate the nuanced understanding of human nature that the various technical experts have taken in talking about how to approach this situation. As an employee of a builder who's dealt with my fair share of homeowner criticism and even anger, I will weigh in here:

    Builders, (I imagine much like doctors), get absolutely bombarded with homeowners requesting impossible things or telling them they're doing all kinds of trivial things wrong, sometimes because "they read it on the internet/saw it on HGTV." They also deal with clients making mountain out of some of the most molehill-feeling of minor scratches, sub issues, scheduling snafus, and well as a good bit of "how dare you not realize that I really wanted it *this* way that I never told you, you're worthless" kind of anger. As well as constant "hey could you change this one thing?" (that will add a lot of time to the job) followed by "I'm incredibly angry that you aren't you finished already!!!" tension. So I do sort of understand why they react the way they do, and coming at them swinging isn't always effective for that reason--they deal with that really often on things that ultimately matter much less, and a person only has so much bandwidth for it.

    However, good builders have good systems for dealing with those things, such as robust communication practices, clear contracts (I really can't over-emphasize that one), and will often fix a fair amount of those things for the customer *anyway* as best they can, for the sake of preserving a relationship with someone who can give them good referrals later. Word of mouth is critical to a builder's pipeline a builder depends on his clients being, if not totally satisfied, at least mollified, when things go wrong in construction. And fundamental water management details such as window flashing and kick-out flashing are worthwhile details, not trivial ones, and builders who want to stay in business must learn from things that went wrong on their jobs in the past. It seems likely that unfortunately this method of window installation is probably pretty common in the area, and it is always harder to get a builder to go against standard practice in his area. (Or to succeed at getting his subs to do so. They work for all the other builders in the area too who don't enforce the same standards, so builders often must engage in the same "enforce an issue vs preserve the relationship of someone I depend on" trade-off with subs, though that *is* part of what we pay builders to do.) It's likely that the area has gotten away with taking this risk for so long because no one has had an issue early enough in the building's life to make the builder's life miserable enough about it to convince him to change, and past clients haven't been saavy enough about building to call it out during construction. The other mitigating aspects, such as guttering and not being hugely exposed to wind-driven rain (and most homeowners' tendencies not open up their own walls or rip off their own siding for fun) has probably helped this practice avoid causing a noticeable problem in the past as well. Still, someone has to call it out, to make the change ever start to happen. As miserable as I've sometimes been when clients have really let me have it--and as undeserved as their anger sometimes was--I've still learned some things that made me better, from those experiences. I'm grateful for them, in a way.

    So yes, it's a calculated risk to call the builder out, but if it's done in an friendly-but-assertive way (rather than aggressive and angry), and especially if taking the tactic of "you know, I wish we'd communicated this better in the beginning, but this is important enough to me that I'm going to insist on it for my most exposed windows, and I am willing to put up X% of the cost, but I need you to cover the rest" I think the risk of alienating the builder is actually pretty low, and the builder is pretty likely to feel a lot of social pressure to comply.

  9. user-7428008 | | #13

    take them out now and do it right! you will be sorry if you do not. will not cost you anything. it was done wrong! just point to mfg directions!
    i see this everyday! no one follows the direction from the material mfg's? wrong tape fish mouth in tape and sloppy installs.
    you should also have a slope which is covered in flashing tape below the windows if no pans are being used which directs water out.

  10. William Janhonen | | #14

    Since I teach building science to Architects, contractors and engineers I thought I might put this into some perspective as it relates to a class I recently held attended by 51 contractors. I asked the class how many installed windows as a regular practice. 51 hands shot up. I then asked the class how many have ever read the manufacturers instructions on how to install windows. Zero hands went up. I then asked the class if they knew that the top (5) window manufacturers required the windows to be installed according to their specifications or the warranty was void. Zero hands went up. Does that put things in perspective?
    When we discussed the "why" the answer was basically that the contractors stated they had been doing this for 20 plus years and their way was the right way. They all said they were "taught" the right way to install a window. I did get a commitment that they would all read the instructions from now on.

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