Allotment Gardening Advice Help Chat

Chatting => Equipment Shed => Topic started by: domw001 on November 12, 2013, 14:21

Title: Greenhouse Glazing Advice
Post by: domw001 on November 12, 2013, 14:21
I have a 10x8 greenhouse on my plot that took a bit of storm damage the other weekend and I lost about 8 panes.
Obviously I need to replace them but should I stick with glass or choose polycarbonate (or could I indeed use both).
Obviously the poly sheets should stand less wind breakages (the GH is a bit exposed), but on the other hand glass panes lend more weight to the overall construction.

Any suggestions?
Title: Re: Greenhouse Glazing Advice
Post by: thedadtony on November 12, 2013, 16:53
Hi Dom, you could have lost the polycarbonate in that wind too in those gales, I'd use glass then apply  a bead of silicone to the glazing bar and the glass on the inside of the greenhouse once it's re- glazed.
Title: Re: Greenhouse Glazing Advice
Post by: domw001 on November 13, 2013, 10:48
a bead of silicone to the glazing bar and the glass on the inside of the greenhouse once it's re- glazed.

My father-in-law suggested that.

I have considered the possibility of losing Poly panels in high wind,  but I know there would be a chance of them still being intact (once I'd driven over to the next county to retrieve them).
Title: Re: Greenhouse Glazing Advice
Post by: Growster... on November 13, 2013, 12:00
I think the added weight and strength of glass should out-weigh the benefits of polycarbonate.

I assume that the latter just bends and eventually pops ou of the frame, so probably sticking is the answer. I certainly is awith a chum round here, but the guy who just put the polycarbonate in with nothing else, lost nearly the whole of his roof!

I'm relying on glass to help keep the greenhouse steady - and sturdy, and so far it has worked, although in 1987, we lost several panes...
Title: Re: Greenhouse Glazing Advice
Post by: anchorman on November 16, 2013, 17:48
Hello Dom, glass will always be the best option but i have a little tip for what its worth. A few years ago high winds blew about 4 panes out of my greenhouse, not on the side facing the dynamic force of the wind but on the sheltered side. I soon fathomed the cause and the cure.

If the greenhouse is closed down, vents and doors shut, strong gusts passing over and around the structure will cause a sudden drop in air pressure outside relative to stable undisturbed air inside. This pressure difference is enough to cause what is effectively an explosion! I found the cure was to open the vent or door a bit when high winds are forecast. Not facing the wind tho' or gusts slamming into the inside of the greenhouse will have a similar effect so only create an opening downwind if possible just enough to allow the air pressure to equalise inside and out as the gusts roll by.

Of course any structure will be wrecked in extreem conditions but so far, i've not lost a single pane in about 6 years. Fortunately, the really high winds are usually associated with rainy weather rather than bitter cold so your plants shouldn't suffer too badly during a few hours of gales. I hope this tip is usefull.