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Cathedral SIPs are sweating in summer

jballard73 | Posted in General Questions on

I have a new home built with SIPS, closed cell polyurethane, R40 roof and R24 walls. The SIPs were installed/built spring of 2014, we moved in Feb 2015. The home is timber frame with Metal unvented roof, the roofer did use vertical furring strips and double bubble over felt. We live in KY and are just now getting into high humid summer, and our center ceiling beams are dripping wet throughout the day, causing small puddles on the floor. The ceiling is hot to the touch at the very peak on either side of the center beam. I believe hot outside air is leaking in. This issue just started and I plan to start calling folks on Monday, builder, SIP manufacture, then timber frame manufacturer until I get an answer. Does anyone have a solution on how to fix? The seams do not have tape on either inside or out of the SIPS, so that would be my first thought, but none are accessible from in or outside. I couldn’t sleep last night thinking how this cost our family over 32,000 for the SIPs and the first summer are failing. Not sure if it matters, but we have spray foam under the rest of the house roof (non cathedral), but SIP walls throughout. The spray foam is doing great the attic is cool and the foam is the all over.

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  1. jballard73 | | #1

    Correction, the roof is invented and has horizontal ( left to right strips under the metal) I believe this is considered a hot roof.

  2. davidmeiland | | #2

    Not sure what "double bubble" is or why it might be installed with the roof. As you allude to, the issue is probably air leakage and the solution is to seal the joints where air is leaking in. The builder, if they respond, will almost certainly want to try caulking next to the beam from the inside, but the real solution is probably to tape from the outside, which of course would be a big challenge. On an unvented roof, the metal panels are probably run very close to the ridge, so that removing the ridge cap would expose almost nothing, but perhaps the ridge cap is large enough to allow some wiggle room up there.

    As to whether there are other air leaks that matter... there might be. A blower door test with infrared inspection would be a good way to pursue this. The person who does that might also be able to measure whether your HVAC is depressurizing your house, contributing to the problem.

  3. ohioandy | | #3

    Exposing the ridge may reveal the other side of this coin--warm moist air leaking out in the winter. Everyone in the SIP racket, from installer to manufacturer to SIPA (the industry association), knows that if these panels are to last they need the belt-and-suspenders approach of multiple air sealing strategies.

    Due to the high pressures of winter stack effect, the most critical interior joint to seal is the peak, that one that is now inaccessible. Not sure what options you are left with. Dig out the SIP manufacturer's manuals, and show the installer the pages about taping interior joints.

  4. jballard73 | | #4

    Double bubble is insulation, primarily reflective. I reviewed my manufacturer instructions and they do not require or even mention tape on seams. They require a 1/2" foam type gasket and voids at seams filled with can type spray foam. The manufacturer is my first call in the morning, we also used the manufacturers installation contractor for the SIPs.

  5. GBA Editor
    Martin Holladay | | #5

    For more information on "double bubble wrap," see this article: Stay Away from Foil-Faced Bubble Wrap.

  6. jballard73 | | #6

    Thanks for all responses, however I only mentioned the bubble wrap in case there may be issue with using it that made my situation worse. The roofer used it and I didn't object but i was also aware it provides little insulation value. The bubble wrap is above the felt and under the metal. My concern isn't the effectiveness of bubble wrap only if it is contributing to my dripping ceiling. Thanks again.

  7. GBA Editor
    Martin Holladay | | #7

    We need more information to know what's going on.

    You tell us that your ceiling beams are "dripping wet," which implies that you have either a roof leak or condensation.

    If you have a roof leak, the drips should be associated with rain. However, you don't mention rain.

    Summertime condensation happens when warm, humid air contacts a cold surface. However, you report that "the ceiling is hot to the touch." We need to come up with a cold surface to explain the condensation, and we don't have a good candidate yet.

    Do you have any air-conditioning ducts up near your ceiling beam?

  8. jballard73 | | #8

    This is not a leaking roof issue, this is condensation. I attached a couple pictures that show the interior view of the ceiling up close - we have galvanized metal on our interior ceiling and you can see the condensation pattern on it as well as on the beam. I also attached a picture I found from my archive of construction photos which I believe explains the cause. My main question is how to repair at this point. I think from inside is my best starting point.

  9. jballard73 | | #9

    A couple more pics for perspective...

  10. GBA Editor
    Martin Holladay | | #10

    OK -- knowing that your ceiling is galvanized steel makes a huge difference in understanding what is going on.

    I'm guessing that you are operating your air conditioner, making your ceiling relatively cold. That's normal. In addition, I am guessing that you have two problems or building defects:

    1. Your house is depressurized with respect to the outdoors, either due to an unbalanced forced-air system or exhaust fans.

    2. There is a major air leak at the ridge of your roof.

  11. jballard73 | | #11

    Thanks again for the response, however it seems we are going around in circles. I agree with all you state, and I think that is roughly what I said from the start - hot humid outside air is coming in along the ridge and causing condensation. My question is still how to repair. I appreciate the input and don't mean to sound curt but I need to fix this, and now, before the problem causes more issues. In my mind the picture of the poorly attached peak/ridge SIP (pic attached above and below) that shows over an inch gap and the gasket sticking out near the middle of the SIP is my issue. I was ignorant during construction, but realized this was not right. I sent the picture to the manufacturer a year ago when it occurred and the response was that my concerns were not valid. I poorly chose to rely on the professional opinion. However, the evidence now is that my concerns are valid. My purpose to posting this question from the start was to try and achieve a complete and thorough fix so as to now hold the manufacturer and their installer to a standard. I believe their is no quick and easy fix, but I also would like more input. Just from my basic understanding I think a possible solution may be to seal the entire ridge from the inside and basically build the ceiling down below some sort of added seal and barrier. Then to follow up with taking the ridge off and sealing from above. I have no idea what could seal it, but I wouldn't be opposed to a solution of adding up to a couple inches to the inside if it assured a bullet proof seal. thanks again

  12. GBA Editor
    Martin Holladay | | #12

    Your builder is responsible for this problem, so you need to pursue a remedy from your builder.

    Once your builder takes responsibility and shows up on the site, he or she will start by removing the ridge flashing. If the removal of the ridge flashing exposes enough of the SIPs on both sides of the ridge to install SIP tape, then the fix would involve spraying the gap between the SIPs with spray foam; trimming the foam after it cures; and then installing SIP tape that is wide enough to stretch from the SIP on one side of the roof, over the ridge, and onto the SIP on the other side of the roof.

    If removal of the ridge flashing doesn't expose enough of the top of the SIPs to perform this work, then the builder will need to remove enough roofing screws to lift or remove the roofing panels -- as needed to gain access to the ridge area.

    While your builder is solving the air leak problem, you can be locating a home performance contractor, and inviting the contractor to visit your house to find out why your house is depressurized with respect to the outdoors.

  13. GBA Editor
    Martin Holladay | | #13

    Here is a link to an article with more information on sealing SIP seams: Air sealing SIP seams.

  14. jballard73 | | #14

    Question is what builder - the SIPs installer or my General Contractor/builder. They are not the same, I used the SIPs install crew with a separate contract outside the responsibility of my general contractor. To be exact I paid the SIPs folks, paid their install crew, and then paid my GC to come in and finish roof, flashing, trim, etc and inside ceiling trim etc. In my mind the SIPs install contractor is the person I need to be talking to.

  15. GBA Editor
    Martin Holladay | | #15

    You are the GC for the SIPs, then. It's up to you to pursue the problem with the crew that you paid.

  16. STEPHEN SHEEHY | | #16

    I used to practice construction law. You need to meet at the site with both the GC and the SIPS contractor. Otherwise, it is highly likely that the SIPS contractor will blame the GC and the GC will blame the SIPS contractor. You need to emphasize that they have a problem and you need it fixed by either or both of them. I'd copy my lawyer on any correspondence.

    One lesson you've learned the hard way is that there is significant risk in carving out a part of the construction of the building envelope and hiring a sub yourself. While the SIPS installer may very well have screwed up, maybe the GC made matters worse. Maybe the GC should have noticed the problem before the roofing went on, but does the GC have an obligation to inspect work by subs hired directly by you? Probably not.

  17. LucyF | | #17


    As a interested and somewhat informed layman, this looks like an exterior problem and if you want it fixed right, I needs to be fixed from the exterior. The metal roof has to come off and install a secondary layer of sheathing after air sealing and insulating that gap. That would completely fix the problem.

    If you attempt to fix it from the interior and cover stuff up on the inside, you may fix it, but you may also only partially fix it and won't find out until years later when things are rotting.

  18. Expert Member
    MALCOLM TAYLOR | | #18

    Stephen wrote:
    "I used to practice construction law."

    Ah - so the real reason your build went so well comes out!

  19. pmwatson | | #19

    Hello Jeremy,

    I'm thinking about using the same SIP supplier (central Indiana)you used for manufacturing and assembly, did they respond to your inquiry and fix your problem? Would you recommend this company? Thanks

  20. davidbitter | | #20

    Your problem made me think of Joe Lstiburek's "Vapor Diffusion Vent"…though it sounds like you may have more than one issue, his article is a good read in any case...
    Get a good on-site assessment by someone who knows something about building science issues or your fix may be only temporary..
    David - AIA,CPHC

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