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Community and Q&A

Window Leaks due to Wind-Driven Rain

Peter0109 | Posted in General Questions on

I have been living in a new construction condo unit since November 2021. Two of my windows facing south tend to leak during storms. The builder came out and attempted to fix the leak problem four times by caulking the affected windows and adding new flashing tapes around them, but it never solved the problem completely. I suspect the rainwater penetrates the exterior wall somewhere else.

Attached are two pictures showing where the leaks are. The water seeps through the line where the window head jamb meets the head jamb extension. I hope these are the right terms to use.

The sheathing is covered by regular vinyl siding and Tyvek housewrap, which is not water-resistive. The builder suggested replacing Tyvek with Ice & Water Shield on the entire wall, and a third-party contractor suggested using Henry Blueskin instead of Tyvek. Do you think these are good solutions?

I found out that damages caused by wind-driven rain are usually not covered by property insurances. Is it typical to construct buildings in a way that they can withstand wind-driven rain? I just wonder if I can actually hold the builder accountable for the leak problem.

Honestly, I don’t know what the actual root cause is. I was making guesses based on my own research and what I learned from the builder and contractors. What can be done to identify the root cause? Is it necessary to remove the siding and housewrap and trace any water marks on the sheathing?

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Replies

  1. Expert Member
    MALCOLM TAYLOR | | #1

    Peter0109,

    Yes, it's a reasonable expectation that all walls be constructed so they do not leak. Unfortunately there is no way of diagnosing the problem, and seeing the extent of the damage, without removing the siding and WRB. Caulking solves nothing.

    Most walls are designed so that they dry to the outside, so while adding an impenetrable membrane like I&WS may help stop water infiltrating from the outside, it will likely cause the wall to experience moisture problems from the interior.

    The best solution would be to re-build the wall with a rain-screen cavity, but if that isn't possible, a well detailed and flashed dimpled house wrap would be my next choice.
    https://benjaminobdyke.com/product/hydrogap-drainable-housewrap/

    Things may be different where you are, but in Canada damage to the building exterior wouldn't be the owner or their insurer's problem. It would be the responsibility of the condominium corporation.

    1. Peter0109 | | #5

      Thank you for suggesting HydroGap! It seems like a great product. I will check with local contractors to see if anyone can help me apply this product to my exterior wall.

      Rebuilding the wall is probably not feasible at this point and would cost a lot more. Unless I am sure I will be reimbursed by the builder, I don't think that's the option I can afford at this moment.

  2. freyr_design | | #2

    From where that is leaking I would bet its at the window head. there was probably no head flashing installed or they installed it poorly. I would guess this is the location as it looks as if that is basically at your ceiling and I would suspect if it was much higher it would hit the floor above and migrate inward. But yes, you will need to get back to the wrb to truly fix that. Before you put the siding back on you should test it with a hose and preferable negative pressure in house, but idk how feasible the depressurization is....

    1. Expert Member
      MALCOLM TAYLOR | | #3

      freyr_design,

      " there was probably no head flashing installed or they installed it poorly."

      I had a similar issue decades ago with an exposed window where I forgot to bed the head-flashing in caulking when installing it.

    2. Peter0109 | | #7

      I am not sure if the head flashing was installed or not because I am not able to access the window without a tall ladder.

      Below is a picture I took when the builder came to caulk the windows a few months ago. Can you tell if the head flashing is there or not?

      1. freyr_design | | #14

        It is very hard to tell from the photo but it at least looks like the overlapping at the head is wrong with the zip tape. You should file a claim with your homeowners insurance and let them settle it with the builders insurance. You shouldn’t have to pay for it or deal with the builder. Ideally you get another builder to come in and give a second (third?) opinion that the insurance company covers

        Edit: I didn’t read that part about not being covered

        1. Peter0109 | | #16

          Thanks, freyr_design!

          If the root cause is wind-driven rain, then the homeowners insurance won't cover it. I have not checked if the policy covers any construction defects. I suppose it doesn't, but I will check with my agent.

  3. Deleted | | #4

    Deleted

  4. walta100 | | #6

    I know this will sound ridiculously simple but get a copy of your windows manufactures instructions. In the instructions you will find the flashing requirements.

    Undoubtably the builder failed to follow the written direction in the instructions. When you point to the directions and how he failed to follow then he might reflash the windows in accordance with the directions or he may tell you to sue him. You would likely win in court but you will almost certainly pay the lawyers more than you will get from the contractor.

    This time make sure the contractor follows the directions.

    Read your condo agreement very carefully. The windows and flashing are very likely considered part of the condos exterior and do not belong to you. The condo board would likely be responsible for any repairs needed.

    Walta

    1. Peter0109 | | #8

      Hello Walta! I will reach out to the window manufacturer for a copy of installation instructions.

      I spoke with two different contractors, and both suggested replacing the Tyvek housewrap with something more water-resistive. One contractor suggested Henry Blueskin in specific. The total cost of repair would be between $7,000 and $10,000. I also spoke to three different attorneys. You are right that it is unlikely I will recover my attorney's fees even if I win the lawsuit. I am thinking to take it to the small claims court if the builder refuses to pay the repair costs.

      Yes, the windows and flashing are part of the building exterior and should be the HOA's responsibility. However, we have a self-managed HOA with little reserve. If I ask the HOA to pay for the repair, I am essentially asking my neighbors to share the cost. I'm still thinking how to bring up this topic to the HOA without hurting relationships with my neighbors.

      1. Patrick_OSullivan | | #9

        > I spoke with two different contractors, and both suggested replacing the Tyvek housewrap with something more water-resistive.

        Those contractors are ignorant. There is nothing wrong with Tyvek, it is "perfectly" water resistant. It just has to be installed properly, and the penetrations flashed accordingly. I see Blueskin installed improperly with greater frequency (i.e. rate) than Tyvek. It's harder to do correctly, and I have mentally noted a variety of properties in my area where there *will* be water intrusion due to how badly the Blueskin was done.

        (This is nothing against Blueskin. Just has to be done right.)

        > Yes, the windows and flashing are part of the building exterior and should be the HOA's responsibility. However, we have a self-managed HOA with little reserve. If I ask the HOA to pay for the repair, I am essentially asking my neighbors to share the cost. I'm still thinking how to bring up this topic to the HOA without hurting relationships with my neighbors.

        Is there anything unique to your unit to suggest you'd be the only one affected by a bad installation? If there are construction details on your unit that are substandard, they may exist in other units, and the HOA might have an existential issue on its hands, that will become everyone's problem, not just yours.

        1. Peter0109 | | #10

          Thanks, Patrick!

          The challenge here is we have not identified the root cause of the water infiltration yet. The two contractors suggested removing all the siding and housewrap around the two affected windows. I am not sure if it is possible to identify the root cause without such a substantial effort. Once the housewrap and siding are removed, I have to install new ones as soon as possible to protect the sheathing.

          Strangely, only 2 out of 9 units in our HOA have been facing the leak problem since we moved in about two years ago. The other unit only has very minor leaks around one window, whereas the leak problem in my unit is much more severe. I suspect it has something to do with the orientation of my windows and the location of my unit, but it is difficult for me to prove.

          1. Patrick_OSullivan | | #11

            > The challenge here is we have not identified the root cause of the water infiltration yet. The two contractors suggested removing all the siding and housewrap around the two affected windows. I am not sure if it is possible to identify the root cause without such a substantial effort. Once the housewrap and siding are removed, I have to install new ones as soon as possible to protect the sheathing.

            Unfortunately, removing siding and housewrap is what needs to be done. But's it's vinyl, so it's not very hard, and it can be reinstalled if not removed by monsters.

            > Strangely, only 2 out of 9 units in our HOA have been facing the leak problem since we moved in about two years ago. The other unit only has very minor leaks around one window, whereas the leak problem in my unit is much more severe. I suspect it has something to do with the orientation of my windows and the location of my unit, but it is difficult for me to prove.

            You said it was "new construction" so the fact that you already have 2 units exhibiting the problem is enough smoke for my tastes.

        2. Peter0109 | | #13

          > Unfortunately, removing siding and housewrap is what needs to be done. But's it's vinyl, so it's not very hard, and it can be reinstalled if not removed by monsters.

          The two contractors I spoke with both proposed to dispose the siding after removal and install brand new ones instead. I am not sure if I can convince them to use the old ones.

          > You said it was "new construction" so the fact that you already have 2 units exhibiting the problem is enough smoke for my tastes.

          I have been asking around in the past two years, but no one seems to show any concern about their units. If fact, the other unit that's experiencing a minor leak problem decided not to address it. I guess it's tough to convince the HOA to address the problem that has not affected anyone else yet.

  5. Peter0109 | | #12

    The picture below shows the front wall of my building. The two windows in red have the leak problem. One contractor suggested the following repair for the area circled in green.

    - Remove double 4" siding and vinyl shingles and dispose.
    - Remove and dispose of existing house wrap.
    - Install flashing tape at two windows.
    - Install new pvc trim at two windows.
    - Install new aluminum flashing above pvc.
    - Install new water-resistive house wrap.
    - Install new white main street double 4" vinyl siding where removed.
    - Install two new white hooded vents at third floor.
    - Install new white double 7" cedar impressions.

    Is this a good approach?

    1. freyr_design | | #15

      Are you able to replicate the effect with a hose? If you are I would be tempted to start by removing drywall on the interior to see if you can identify the issue. It is possible it’s the window itself, which should be covered by window warranty. I would be reticent to just go replacing things without identification. You may even be able to use something like an inspection camera to just drill a hole in drywall and see what is happening. It will be a bummer to go through all that to find out you needed to replace the window and not all your siding up to your roofline. Or that it is just how that specific window is flashed, in which case you probably should fix the rest of the windows and document for a claim against builder.

      1. Peter0109 | | #17

        I would need a really long hose to reach these two windows. They are on the second and third floors of this building. I am more concerned if the water pressure is high enough to replicate the effect.

        I think I need to remove the head jamb extension to see how water flows into the unit. I suppose the window is secured to the wall sheathing by nailing fins. Removing the head jamb extension should be fine, right?

        The builder mentioned to me before that strong winds might push rainwater upward along the exterior wall. If the rainwater moves upward instead of downward, it may be possible for it to get behind the house wrap. Do you think it is a valid concern?

  6. walta100 | | #18

    The smart move maybe to disclose the leak and sell this condo before you become aware that mold is growing in the walls of every unit in the complex, the builder can file for bankruptcy and the condo board must declares the $30,000 per unit special assessment.

    Walta

    1. Peter0109 | | #29

      That's an option I considered before, but both the interest rate and housing prices are a lot higher than three years ago when I bought this condo. If I switch to a new property now, my monthly payment will go up significantly.

  7. canada_deck | | #19

    It is interesting to see how this is dealt with in your jurisdiction. In British Columbia, Canada, every condo has a 2-5-10 warranty. The five year covers the building envelope, including water penetration.

    Generally in a building like this in British Columbia, the building envelope is the responsibility of the strata corporation (similar to the HOA.) An individual unit owner would not be doing what you are doing. In fact, they would not be allowed to do what you are doing without a lot of involvement from the strata council. Any modifications to the envelope would have to be approved by the strata council and you may be asked to accept full liability for any modifications that you initiate. In a situation like this, you would complain to the strata and they would have a formal duty to take steps to correct the issue and they would be making the decisions. Costs would be allocated from the strata budget that all owners pay into and you would not be taking on any liability in the event that the repairs are unsuccessful or cause even more damage. In the event that legal action is needed (e.g. against the developer,) it would be the strata that would initiate it. My experience is generally with larger multi-unit buildings (e.g. 80 units.) There may be some exceptions in smaller buildings in my area.

    I do encourage you to make sure you are fully up to speed on all the laws and common practices in your area.

    Earlier in the thread, you said: " If I ask the HOA to pay for the repair, I am essentially asking my neighbors to share the cost."

    Keep in mind that if that is the normal practice in your area (or stipulated by the law or bylaws,) then it is what should be done. How will you feel if you pay for the full cost of this repair and then next year the windows on neighboring units leak and it is covered through a special assessment that you are required to pay into?

    1. Patrick_OSullivan | | #20

      > How will you feel if you pay for the full cost of this repair and then next year the windows on neighboring units leak and it is covered through a special assessment that you are required to pay into?

      Had the same exact thought.

      1. Peter0109 | | #30

        I have spoken to three lawyers already. Unfortunately, the total cost of repair (~$10,000) would not justify the cost of hiring a lawyer. One lawyer mentioned that if the case goes to court, it could take years and cost thousands of dollars, suggesting that fixing the windows may be a better option. The general advice is to send a demand letter to the builder, hire a contractor to fix the problem, and then file a small claims case against the builder.

        I also spoke to the president of our HOA last week. He agreed to help me address this issue. If the builder does not pay for the repair, the HOA will cover the expenses.

        1. walta100 | | #32

          “I also spoke to the president of our HOA last week. He agreed to help me address this issue. If the builder does not pay for the repair, the HOA will cover the expenses.”

          Talk is cheap get him to put what you think he said in an email or text and print a copy.

          Before you hire anyone to work on any part of the building that the HOA is responsible for be sure you have written permission from the HOA allowing the work and make it clear in everyone’s mind who is paying for what and how much. Until the siding is off it is impossible to know how bad is the problem with your unit.

          Consider the possibility you have someone open the wall fix your problem later the HOA decides that you caused some other problems by open the wall without their permission and you must pay them to fix your unapproved work.

          Walta

          1. Peter0109 | | #33

            Sounds good. I will ask for the HOA's permission in writing. Thank you for your advice!

  8. Patrick_OSullivan | | #21

    Thread title change SEO optimization strikes again. Bad form, GBA/Taunton folks. Bad. Form.

    "Finding the Cause of Water Leaks" is way less descriptive than "Window Leakage due to Wind-driven Rain".

    I'll say it again: polices and tactics like this water down a site's value and make it less attractive to those that contribute to it in the first place, undermining the value of the content you're trying to monetize.

    You are doing it wrong!

    1. canada_deck | | #22

      It's absolutely horrendous. I've never used another forum that does this. Makes it very hard to keep track of active discussions.

      1. Patrick_OSullivan | | #23

        Exactly. So I sometimes just give up. Or lose track of threads I was otherwise actively participating in. Which goes to the main point: this practice makes those that contribute less likely to do so.

    2. andy_ | | #28

      This thread title change thing is sooooo infuriating! WHY? If they really needed to do it for clarity, or even SEO, why not do it like any rational mod would? Just put the new title with a "New Title (Was: Old Title)" then we who actually generate all the free content can find it and your beloved searchbots will too.

  9. Expert Member
    Akos | | #24

    +1 On a hose test first to find the leak source.

    Work your way slowly up the windows and siding. 10 min at least at each location, use a watch as 10min feels like a very long time when you are standing there.

    I would not be surprised that the min floor window leak is caused by flashing issues at the bottom of the 2nd floor window.

  10. Expert Member
    KOHTA UENO | | #25

    One suggestion of a possible "simple" cause of the problem--the lapping of the head flashing. Most window and housewrap manufacturers recommend a "flap" detail at the window head, so that any water that has gotten behind the housewrap *above* the window can get out. *If* this is the case, it is is something that could be fixed in a "minimally invasive" manner. No idea whether it is the case for your building though.

    BSI-067: Stuck On You
    https://buildingscience.com/documents/insights/bsi-067-stuck-on-you

    "At penetrations such as windows and doors (Figure 1) we have learned to “scrape the water off the sheathing at the tops of the windows by taping the top flange of the window directly to the sheathing under the building wrap (Figure 2). This is a big deal. If we didn’t do this the water running behind the building wrap would wet the top of the window opening interior finish and folks would see it. We don’t care if this water leaks through a joint in the sheathing in the field of the wall because the wet spot isn’t seen by anyone. And if the wall is designed to dry either to the interior or exterior or both it does not matter anyway.3 Recall, that this amount of water is small."

    1. Patrick_OSullivan | | #26

      Kohta,

      Thanks for referencing this detail. In my humble opinion, it's great advice.

      At the risk of a bit of a non-sequitur, I have a question about Figure 3 and this statement in that paper, namely: "A heavy bead of sealant is installed behind the flange of a window and it acts like a “gasket” smushing the building wrap against the sheathing limiting the water that can run sideways into the opening. The “red arrow” shows the “smush” direction created by screwing the window flange into the sheathing and frame opening."

      If I understand the diagram correctly, the sealant exists between the WRB and the flange. There is also flashing tape over the WRB and flange. But this "smush" terminology makes me think the intent of this advice is that the sealant helps to provide uniform clamping pressure under the flange, but between the WRB and the sheathing, such that incidental water beneath the WRB cannot move horizontally under the flange. Is my assessment correct?

      In Zip installations (and theoretically similar for liquid WRB or fully adhered WRB), and where the flange is integral to the window, I advocate for *no* sealant under the flange because it is a messy detail to execute, and I see no incremental benefit to it when you are properly flashing the flange.

      If my understanding of the intent behind the detail in Figure 3 is correct, it could mean the benefit/effect of sealant is different in a sheet WRB application vs a fully adhered WRB application. Does this sound like a reasonable interpretation?

    2. Peter0109 | | #31

      I think the builder did put the flashing tape behind the house wrap at the top of the window.

      How does this method prevent rainwater from getting behind the house wrap right above the window, in case the wind is strong? The builder suggested that the rainwater might be driven upwards along the wall. This method is designed to allow any rainwater behind the house wrap to get out above the window, can it also become a source of water infiltration when rainwater flows upwards?

      I wonder if this is a valid concern or if the builder was just messing with me.

  11. Expert Member
    Michael Maines | | #27

    I've seen multiple projects with similar details leak. It often seems to be at the water table, which is just nailed directly to the WRB without a drip cap, or if there is a drip cap it just sits on the face of the WRB.

    The WRB is rarely watertight where the wall meets the soffit; if the wind blows when it's raining like it does where I live, that could be another infiltration source.

    I bet the detailing at the wall overhang is not water-tight either.

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