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velux skylight ROT

wallyo | Posted in Construction Techniques on January 9, 2008 09:04am

Just wondering if anyone has run into this problem. Have a Velux skylight mounted above a 4×6 jetted tub, the ceiling is cathedral-ed, the glass is 14″ from sheetrock surface 9′ above the tub floor, the tub gets used two to three times a week. The box for the light is perpendicular to the ceiling joists meaning the bottom kicks in a bit or it does not flare out. There is an oversized exhaust ceiling fan about 3′ away on the same side

The problem is this; on the bottom two corners I have rot, more so on the left side then the right. At first I thought it was just a little staining but it has gotten bigger and seems to of shown up just this winter it is soft and punky. I oiled the wood with watco but never a poly top coat. The corner tape of the sheetrock failed. What I cannot figure is this due to internal condensation or an external leak. Been a bit too cold to get the hose out and spray it. Has not rained but has snowed every other day 1 to 2 “. If it is the seal, it is a slow leak there is no water dripping. If a condensation problem what to do about it. Replace the unit, somehow repair the wood with epoxy paint it, take the unit out this summer remove the bottom wood and make a replacement piece?

Has anyone else had this happen. People put these all the time in hot tub rooms and above pools. Velux says seal on that unit were (operative word) warranted for ten years. Mine is 12 purchased 96. Thought I was buying the best which I may have, could be the installer.
This is not the first I have installed.

All thoughts appreciated

Wallyo

Edited 1/9/2008 1:11 pm ET by wallyo


Edited 1/9/2008 2:28 pm ET by wallyo

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  1. user-201496 | Jan 09, 2008 10:00pm | #1

    You have an external leak. Time to replace the whole unit.

    1. wallyo | Jan 09, 2008 10:04pm | #2

      That is how I am leaning but what makes you think that, is it something you have come accross before? I just don't want it happening again.Wallyo

    2. Piffin | Jan 09, 2008 10:21pm | #3

      I don't know what you are seeing that indicates an external leak. I agree that it needs to be replaced if that wood is already gone punky. simply painting it with epoxy will not do muc. It would need to be injected in a time consuming process in a hard to reach location, and with the wood in the present condition, the seals are probably shot.But this was more than likely not caused by condensation due to the location. I could be wrong, but there is absolutely nothing in the photos to indicate what you say that it is external. 

       

      Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

      1. wallyo | Jan 09, 2008 10:26pm | #4

        A little confusion on my part meant to repair with epoxy then paint with a good quality exterior paint perhaps. In other woods don't need the natural wood.

        1. Piffin | Jan 09, 2008 10:39pm | #5

          OK.That is an option perhaps, but with the wood having gone punky, that tells me it has done a lot of moving.So the seal between the glass and the wood frame you see there has been stressed so there could be additional problems now that diod not exist five years ago.95% of the time, when there is an external leak, the staining is in the sheetrock and not up all the way on the exposed wood of the skylight frame, because the leak happens in the flashing detail. And most of the time, that leaking is at the top of the skylight.When it is where you show it, the water has been condensing on the cool glass, and running down and wicking into the wood there.Skylights in bathrooms are famous for this sort of problem.
          Velux is indeed the best you can get in a typically available unit, but you still need to maintain it. You could also consider a tn operating venting unit for the replacement.with an epoxy repair, you have to drill holes to inject the epoxy, so be carefull to use a stop on the drill bit or you wil be drilling too deep and right out into the flashing materials. 

           

          Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

      2. user-201496 | Jan 09, 2008 11:18pm | #8

        I've seen it many times before. Rarely would there be enough condensation to cause rot on sealed wood uphill. It could happen but I am almost certain the skylight has a leak on the exterior.

        1. Piffin | Jan 09, 2008 11:23pm | #9

          Not rare at all. I see condensation cause water staining there fairly often in bathrooms. Usually comes to my attention with a call from HO asking why is water dripping on my head? The problem is never in the top in the ones I've seen. For it to be leaking above like that, it has to be getting in between glass and wood, which is very rare indeed. It is possible that it is now leaking there in wind conditions since the wood has been swelling already and stressing that seal for years. 

           

          Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

  2. theslateman | Jan 09, 2008 11:04pm | #6

    That is an inoperable unit- if you do replace it you might want to consider a venting one.

    They make an extension pole so you can open it up for some ventilation and exhaust out some of the moisture laden air.

    1. JohnCujie | Jan 09, 2008 11:09pm | #7

      Shouldn't there be an internal gutter and weephole system as part of the skylight? Velux is pretty smart, I'm sure they have dealt with condensation. Maybe the weepholes were clogged.John

      1. wallyo | Jan 10, 2008 12:35am | #12

        John you make a real good point. Called Velux to check it out, was transfered to tech. Was told there ARE weep holes on skylights made after mid 95. Mine was november 95. That they can get clogged by debries or Ice damming, there is a rubber gutter between the glass and frame and two molded mazes towards the center bottom of the unit. These mazes let the water out but stop wind. He said get up there with ablow drier and run it across the frame to glass area.He thinks my problem could be clogged weep holes or the fact that my unit does not have low e glass (at that time it was an option) which causes exccesive condisation. He suggested if I replace it to go with the low e laminated glass. So is the problem internal, external or both?Wallyo

        Edited 1/9/2008 4:38 pm ET by wallyo

        1. theslateman | Jan 10, 2008 12:38am | #13

          Time for an upgrade- then sit back and relax like Seeyou says.

          He's buying- just the beer though

  3. timkline | Jan 10, 2008 12:07am | #10

    I can just about guarantee you that you have a condensation issue.

    The condensation can clearly be seen in the left photo.

    It sounds like it is in your house.  After using the bathtub or shower, do you have heavy condensation build-up on the glass ?   Are you religous about using the exhaust fan ?   Is the exhaust fan actually working  ?   Is it vented down and out of the soffit  ?

    This is a typical problem in bathrooms with skylights.

    Your house could have compounding issues as well.  Do you have a whole house humidifier ?  Basement crawl space ?  How is your clothes drier vented ?  Do you have family taking long showers ?

    There are a lot of issues that affect the humidity level in your house.

    Velux does not make skylights with condensation drip pans and there are no weeps to be blocked.

    In replacing the entire unit you could consider the FSF series with ventilating flap or the VS units which open manually with pole or electrically with controls.

    carpenter in transition



    Edited 1/9/2008 4:10 pm ET by timkline

    1. wallyo | Jan 10, 2008 12:57am | #14

      Yes it is my house. Tub only, there is a shower but have not used it yet, this is a shoemaker remodel addition. Ran into a Weck glass block problem on the shower (they changed color etc, everyone here drop carrying it, and even though I brought it at the same time I had two colors and the new color was also different. Just brought all new on a trip to OR that is the all the same color, Anyone for a deal on block?)There is condensation on the glass, heavy no more then past winters.exhaust fan used 50% of time, vents directly to the roof. is working.Crawl spacedrier direct out wall behind it and it is venting.Shower in other bath vent on always during.What is weird is the bathroom we shower in has an insulated plastic bubble skylight. never any condensation on it, but that one is way up from the ceiling, the shaft is 5' up probably what get up cools before it condenses?Wallyo

      Edited 1/9/2008 5:01 pm ET by wallyo

  4. seeyou | Jan 10, 2008 12:35am | #11

    Looks like condensation to me as well since it's stained all the way across the bottom. There's an easy way to tell. Tear the drywall that you're going to have to replace out so you can see the flashing from inside and check it out the next time it rains.

    As far as epoxying, by the time you fool around with all of that you could swap the S/L out for a new one and be sitting in your tub smoking a cigar drinking a beer.

    http://grantlogan.net/

     

    My mother once said to me, "Elwood" -- she always called me Elwood -- "Elwood, in this world you must be oh so smart or oh so pleasant." For years I tried smart. I recommend pleasant.
    Elwood P. Dowde (James Stewart), "Harvey"

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