I had our roof replaced going on 2 yrs ago and at that time we had a ODL tubular skylight installed in a central bathroom (no windows so wanted the light; no fan or lights, just a tubular skylight with no bells or whistles).
Everything has been fine but no all of a sudden i noticed a water stain around it on the ceiling.
I took the diffuser or lense part off and there was a little condensation on top of the plastic lense. No real glaring sign of drips or water spots on the inside of the tube though.
Went up on the roof and on the dome on top of the roof there is quite a bit of condensed water drops (I took some pictures and can post if anyone wants to see it).
I didn't really do anything now other than to look and take pictures. There are a few nails used on the flashing which are "caulked" (looks like clear silicone sealant to me).
I have heard of putting insulation around the outside of the tube to prevent condensation, not sure if this is part of the problem. I'd be cabable of doing this I believe, not a great place to get to but have been up there a few times. House is a tri level BTW and the baths are both on the upper level.
Other thought I had is to try to keep air out of the tube?? This is in a bathroom so could be getting excess moisture from showers I was thinking. It hasn't been an especially tough winter here in southern Wisconsin so not sure why it's acting up this year and not last year.
Gilly

Here is a link to a picture of the dome:
https://picasaweb.google.com/lh/phot...eat=directlink

 

Hi Gilly,
Condensation is the issue and it is a combination of cold and inside air. Bathroom air would be worse, but regular old inside air will condense at less than outside temperatures. Place a glass of ice water on the counter and watch the moisture flow and that is 32°. So your thinking is correct, but do both, insulate and seal our any inside air.

As for "why now" not sure, but other changes involving intake or exhausting air can change the pressures within a home and result in air being pulled in or pushed out in other places.

The picture certainly looks like warm air is getting up to that cold dome, which it should never be able to do.

Bud

 

Thanks Bud. Do you think removing the diffuser will allow it to dry out, or will I need to do more than that? Yesterday was my golden opportunity to go up and look at it and get some pics. Snowing a lot today. I figured if I had another nice day toay that I'd take the dome off and dry it manually. No such luck. Also is there a product made specific to the purpose of insulating a tube like this?

 

Took the diffuser off and I do see some light condensation on the inside of the tube itself now, like what you said, the type you get on a cold glass of water on a warm summer day, but not to the point of dripping, just like a fog.
I am curious as to how I could better seal the diffuser to the tube without making it non-removeable, I think that might fix it. I know it will still have some air getting in, because there are several section of tube (basic install kit plus one extension kit to make it reach). But it would reason that most of the humidity is from showering, not the joints in the attic.

Right now, this is kind of cute, I took a step ladder and put a very small desk fan (plug in type) and have that blowing up in to the tube right now to see if it'll dry it out.
Gilly

PS Bud, I know you are the guy who helped me with my Selectrics, I didn't know you did other stuff too.

 

The leaks from the tube to the attic might be what is pulling the warm air in from the bathroom. Here is an analogy.

Large picture window, nice and clear on a cold winter day. When you head off to bed you close the drapes. In the morning you open them and the window has been raining moisture all over. What happened? during the day the window was nice and warm because the heat could get to it. When the drapes were closed they blocked the majority of the heat, but a trickle of air could still circulate by convection bringing a constant supply of household air in to be cooler by the now colder window. Thus the condensation. In your case, sealing in the attic as well as sealing in the bathroom would be intended to stop that trickle of inside air from reaching the cold surfaces of the tube. Insulation takes that one further step by trying to isolate it from the cold. I'm not that familiar with light tubes, but I would have thought the mfg would have been up to speed on this. Maybe you could fabricate a foam rubber gasket if I'm picturing the bathroom leak correctly. For duct leakage they like the foil tape where you don't have to take things apart often.

In addition to a career in electronics I have been in construction on the side for many years. Once retired from electronics I took up energy auditing and now mostly consult as opposed to climb through attics. It is fun though. It's funny, try mentioning a typewriter to kids today and they think you are from another planet.

Bud

 

Heh heh, yeah sort of like a computer but no RAM or ROM. Or Hard drive. But does have a printer. Sort of. No internet connection though.

The tube is sort of like a cylindrical heater duct which is chromey inside. The dome is designed to catch the sunlight and direct it down the tube (there is an orientation to help with this, have to face one side, I want to say south, might be north, but anyways it is attached with the direction of the sun in mind. Light then goes down the tube and is diffused, like any light diffuser, say like a flourescent light fixture. This one is energy star rated as it has very very little temp gain due to the sun, which I can attest to, it is not any hotter in the bathroom io full sun days vs night time, no heat comes off it at all.
Now it does seem to me that this did come with some of that chrome-looking tape. I know I had some when they were done. Right now I can not say for sure if they actually used ANY of it. They may have, and I have just left-over. But given the dissatisfaction I have about the roof (another story) I would not doubt the boneheads neglected to tape off the seams. There are several. You get a certain length of tube with the kit, and you can get kits if you need more length to get out of attic with it, I did need to buy one extender kit to get the length, so yes that means more joints that could leak if they didn't tape them up. Was quite cold to the touch in the tube this morning. Although it runs through the attic which is of course a cold zone so it makes sense.
Am really starting to think I should get in the attic and take a peek at the joints on the tube to see if they are taped.

 

Sort of basic installation info, this is the brand that I have also, ODL, they sell them at Home Depoe
ODL: DIY tubular skylight installation, how to install a skylight

 

I'm familiar with the function of the units, just never installed one to know how they seal the inside finish to the tube and ceiling. You wouldn't want air leaking in around the tube any more than into the tube. Passing through the attic should entail some form of insulation I would think.

It's funny you mention the Energy Star rating, but with your location, zero heat transfer sounds backwards, like that unit is for down south. I know the low solar gain energy star windows they promote up in my cold country belong down south.

have you talked to the company that installed this? Sounds like they might be on the hook for some of this work?

Bud

 

No I haven't talked to them. It's sort of related to the "that's another story" comment I made earlier. I've moved on, pretty sore about the roofing job that was done, and they did this install at the same time. About all I will say now if that the house is about 17 yrs old, we'll probably be here at least another 15 yrs, Good Lord willing, and we are planning on new windows, probably get the deck replaced or significantly upgraded, and probably other needed work (we redid the mechanicals a year ago through my brother in law), and this contractor ain't seeing another dime from us. And this contractor did the deck the first time (OK with that) and finished our lower level, so yeah he has gotten good money from us in the past. The roof job, my opinion is he hired a lousy sub to do it.

I have been in contact with ODL and they are very responsive, happy with them.
I feel it's really probable they taped none of the joints. I will take a peek at it tomorrow, ODL said they will send a couple rolls of that metal tape if I need it.
I took that small fan and attached it to the end of a long cardboard tube and had it up the sun tube about 3/4 of the way. It seemed to help some, but a few minutes after removing it I think it was fogging up again right away. I was getting dark outside so not as much light in the tube, so not really sure 100%.
The energy star/solar gain thing, yes would be important in the summer time. I see what you mean about heat gain in the winter being a good thing, but I think I am better off with the lack of heat gain.

 

Oh and probably the only thing left to ask is if I should get some sort of wrap to insulate the tube? The first thing I need to do is see if the joints are wrapped, if not I will do that, and sort of wondering if I should insulate the tube even if the joints are taped.
I think I have seen wraps for heater ducts which is sort of foil on one side and fiberglass on the other side.

 

For drying out the inside you should use dry air. Outside air would be the driest source without setting up a dehumidifier. But that should be done just before you close it up when done. Actually, assuming it is leaking to the outside, turn that fan around and pull in some cold dry air. You will also want to clean those inside surfaces as best possible at the end.

As for insulation, again the mfg should have a recommendation, but duct insulation is the right idea.

"One can only maintain so many toys."

Bud

 

For right now I should concentrate on check for the cause, that I can fix. Then will get it all dried out. If I pull the dome I can dry that and also wipe down the upper part of the tube, then wipe down the lower, I think I can do the whole tube in that manner. Just won't be able to get on the roof now for awhile. Make sense?

 

Bud
The mfr (ODL, who once again I'd like to commend for excellent customer service) is saying they have an additional lens which goes below the dome to seal it and preventing moisture. So sounds like this may be a known problem. They will send that lens gratis along with additional tape.
The joints are taped except the very top joint, where the tube connects to the bottom of the housing which the dome attaches to, on that one I can distinctly see light all the way around, as far as i can see anyways from my vantage point in the access hole to the attic area.
I will need to get on the roof (which I prefer over entering the attic) to remove the dome and install the lens, and then will dry out the tube with rags.
Gilly