Both ends are sealed but bottom ones have small holes in it. Only some panels seem to get more foggy than others🤔 they r old and reused from another greenhouse. The greenhouse is still open both ends and some on the roof. What u think?
by fllavour
7 Comments
Unless there are proper rubber washers under the heads of the screws that fix it to the timber, moisture will be getting through screw hole & into the voids of the poly panels, causing condensation. I think some folk also put silicone sealant as well as rubber washers for this reason.
There is a seal failure somewhere, and the insulation space is not ‘working’.
You often see this in sealed window units in homes. When a window is foggy or has condensation in a home and others do not, the window seal has failed and you need a new window.
I’m not sure about polycarbonate as I do not have any of those panels, but with windows (2 pane with air space in between) it does.
Hope that at least points you in some direction that can help.
The panels either have microscopic holes in them letting moisture in or when they were sealed moisture was trapped inside. If the latter is the case the condensation will appear with temperature changes but not humidity changes. If the latter it will appear when the humidity goes up. I wouldn’t worry about it polycarbonate panels tend to do this over time.
Mine do that too. They will dry from the sun.
I took a shop vac along the bottom of mine. Making sure to get each channel. Seemed to help quite a bit.
It’s literally the greenhouse effect
Maybe a dumb question, but did you put breathing tape on the ends, or are they sealed off?