On Sun, 18 Jan 2004 10:11:59 -0500, Trent-Lion wrote:

I, a rank amateur and non-handy person, am trying to restore an old GH
with aluminum frame. I replaced the glass with twinwall polycarbonate
sheets. The frame has a groove in the bottom where the glass used to fit
and into which I fitted the poly. I could see no way to allow for drainage
at the bottom of the sheets. Both ends of the sheets are tightly sealed
with caulk, and I put more caulk at the bottom, to help the sheets slide
into the frame groove and to seal the juncture of sheet and frame.

Now most channels of the poly look fine and clear, but a lot of them stay
cloudy from moisture (making for an unsightly appearance), and in some
channels several inches of water has collected at the bottom.

I don't understand why the channels are behaving differently. But more
importantly, am I stuck with this condensation/water problem forever,
because I sealed both ends of the channels with caulk? All I can see to do
to remove the water is drill a small hole at the bottom of the affected
channels and let the water drain out or perhaps pull it out with a
hypodermic syringe. Or perhaps the water will evaporate when hot weather
comes.

The weather in north FL where I am located has varied from the 30s to
about 70 since I installed the sheets. Will the problem get better or
worse when hot weather comes?

Thanks for help.


Without knowing your setup, I am not so sure I would have been so eager to
seal the poly panels. Moisture has gotten in several with nowhere to go.
If you can, remove the cloudy panels and let them dry complete. Check
them for hairline cracks. Once dried, you could reseal. Since you are in
an area where temps aren't too extreme, I think you'd be safe not to seal.

You could also check the channels where they go and drill drain holes to
allow for drainage.

Greenhouses aren't necessarily supposed to be airtight. I'm not so sure
you really want to make the entire structure inflexible.