On Jan 20, 10:43*am, Eric in North TX wrote:
On Jan 20, 9:22*am, willshak wrote:





on 1/20/2009 8:58 AM (ET) Eric in North TX wrote the following:

On Jan 20, 6:42 am, willshak wrote:

on 1/20/2009 2:24 AM (ET) Aaron Fude wrote the following:

Hi,

This topic had come up before, but I keep getting conflicting advice
so I wanted to dedicate a thread to it.

When boxing in skylights, I being told that one does not want to use
drywall for the skylight window bay. The supposed reason: either the
hot air, or the humidity, or the intense sunlight will rot the drywall
over time and one ought to use plywood. In this newsgroup, I believe,
I only heard the opinion that this is either total nonsense or, at
best, obsolete old school idea.

So, if you do agree with plywood over drywall, please post your
opinion and your reasoning.

Many thanks in advance,

Aaron

There are probably millions of skylight bays covered in sheetrock.
Perhaps all the contractors have never consulted the person that told
you that .

--

Bill
In Hamptonburgh, NY
In the original Orange County. Est. 1683
To email, remove the double zeroes after @

There are millions of porch ceilings in the south done in drywall,
that doesn't make it right.
Any place moisture is a distinct possibility, dry wall is a poor
choice. That is done because it is cheap and the installers will be
long gone by the time trouble arises.

What is the difference between the construction of skylights and
ceilings with unheated attics above, or outside walls ?
Skylight bays should be insulated as well as those ceilings and outside
walls.

--

Bill
In Hamptonburgh, NY
In the original Orange County. Est. 1683
To email, remove the double zeroes after @

I'd say the main difference is the placement of a horizontal (or
nearly so) window directly above. I'm sure skylight are designed to at
least minimize leakage, but it is still less so than a roof.
One good hail storm and the design could likely change drastically.- Hide quoted text -

- Show quoted text -


All the skylights I ever owned weren't designed to minimize leakage.
They simply don't leak. And if they do, then they were installed
wrong or have failed and need to be replaced. I guess you could
prepare for possible catastrophic failure by shattering of the window,
but I think if that happens, you usually have bigger issues than
drywall vs plywood. In fact, I would probably rather have drywall
than plywood because not only is it less work to install initially,
even if you have to replace it following window failure, it's no big
deal.

To answer willshak's question, I'd say a skylight is different than a
ceiling with an attic or similar over it in this way. The attic will
have insulation between the cold attic space and the ceiling. In the
case of a skylight, the area of vertical drywall approaching the
skylight has minimal or no insulation. In my home for example, I
have skylights in a cathedral ceiling. The last few inches of
vertical drywall has very little insulation compared to the rest of
the ceiling. In that regard, it's like any other window. And all my
windows are finished with wood trim, not drywall. But as I said
previously, no problems here in NJ. I don't have condensation on
either the skylights or window trim.