# Insulating a skylight



## cybishop (Dec 19, 2012)

So, first a little background: my fiancée and I bought a house three months ago. It has no attic, just a crawlspace about 2 feet wide with insulation between the joists. One feature about the house we liked was a skylight in the bathroom, for both more light and more ventilation. There's a shaft for the skylight with vents into the crawlspace and I'm pretty sure (never been up on the roof on the roof myself, we haven't got around to buying a ladder big enough yet) there are also vents into the outdoors itself. The window on the ceiling of the bathroom is even on a hinge, so we can open and close the skylight simply by pulling a chain. 

The problem is insulation. A guy from an insulation company recommended simply covering the insulation vents entirely. We don't want to do that because most of the year having more ventilation there is nice, it's just four months or so when it's a problem. There is another vent, but it's much smaller. However, we can't figure out what to do with it during the winter.

I have tried putting up that plastic wrap you can put over windows (I don't remember the exact name, but I can find the package if necessary) on the inside of the window in the ceiling for a little extra insulation. It began peeling in just a couple of days. I'm not sure whether the problem was my ineptness (never used the stuff before), the fact that it's not meant to be used on a skylight, or the steam of the shower nearby, but two problems out of three I can do nothing about. 

My next thought is weatherstripping like for a door, but that might have the same problem. Should I give it a try and just hope its adhesive is stronger than the plastic wrap? Should I give up on keeping the vents functional and insulate them permanently? Is there something simple we haven't thought of yet?


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## joecaption (Nov 30, 2011)

Post makes no since to me.
Why would there be vent that that go's to the crawl space under the house to the bathroom?
A sky light in a bathroom is always going to be an on going issue.
Some pictures may help.


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## cybishop (Dec 19, 2012)

joecaption said:


> Post makes no since to me.
> Why would there be vent that that go's to the crawl space under the house to the bathroom?
> A sky light in a bathroom is always going to be an on going issue.
> Some pictures may help.


There is a crawl space under the house, but that has nothing to do with this. The bathroom is on the second floor. I was just trying to say that there isn't a full attic. Maybe I shouldn't have gone into that much detail. 

I've attached a picture. The plastic wrap is still up there because I haven't got around to taking it down yet, but one corner of it is already hanging down. I'd attach a picture with a better view up the shaft, but I work about 8 to 5 so a picture wouldn't come out well after dark. Maybe I'll take more this weekend.


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## HomeSealed (Jan 3, 2008)

So there are vents from the skylight tunnel/shaft into the attic? That doesn't make much sense to me, I'd seal those like the other guy mentioned. If you want to retain the venting function out the roof, that's fine, you'll just want to weatherstrip the inner panel. They have mechanically fastened weatherstripping that works much better than the stick-on stuff, and then you can install a latch to make sure it closes nice and snug. It is a similar treatment to the way you would seal any attic scuttle. Lastly, it looks like that is some old single pane glass, so attaching some type of storm panel on the outside/top of the unit would be helpful as well, and retain the nice look to the interior.


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## Windows on Wash (Aug 30, 2011)

A picture from outside would probably still help here but if you want to make it more efficient, it is probably time for a double pane retrofit with some venting ability.


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## Gary in WA (Mar 11, 2009)

Problem with some older ideas is the skylight is not safety glazed. Keep up on your H.O. Insurance premiums... the vents in the shaft to the attic crawl-space should not allow room air to the attic, ever. Major heat/moisture loss and dangerous in a fire from/to the bathroom.

Gary

PS. you forgot the hair-dryer; to shrink the shrink-wrap plastic, step.


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## cybishop (Dec 19, 2012)

So the recommendations are mechanically-fastened weatherstripping, closing off the vents into the attic, and a dual pane? Got it, thanks. Sounds like a big job, though. I'll definitely want to do it - I know how easy it is to put stuff off - but it's already winter, so until spring comes I think try another temporary option, like stick-on weatherstripping. That should hold better than the plastic wrap, at least, since it's actually in the frame.



GBR in WA said:


> PS. you forgot the hair-dryer; to shrink the shrink-wrap plastic, step.


I did use a hair-dryer. I guess I could have done it poorly, but it was hanging loose on two corners within days, so either I screwed up with the hair-dryer on _two _corners or there's a problem with using the plastic on a window like this.


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