Glass or plastic Hot House? Oh how many forums deal with this question!
Glass Discussion
While it was an obvious consideration, we didn’t think too hard about this option as we ruled it out quite early in the planning. Glass is pricey and difficult to handle requiring some nifty building skills to utilise. Some people build greenhouses from lots of old windows from builder’s yards – we think this is great but wasn’t for us because we wanted a big hot house.
So plastic it was to be then. Time to research.
Plastic, plastic, plastic. And UV
We spent hours reading up on the characteristics of different plastic roofs and material, and in the end came back to our basic project brief: a large, strong greenhouse, simple to make for around $1000. As soon as we looked at super-duper UV plastic or perspex panels, the price crept up and up – over $2000! We may as well have bought a professionally designed product and sat back while someone made it happen for us.
We wanted to rediscover things for ourselves.
For the greenhouse roof? The cheap corrugated plastic opaque roofing from local hardware stores seemed perfect. Sorted.
For the greenhouse walls? The same rip-proof plastic sheet used on huge commercial greenhouses and available by the metre on TradeMe. We figured, if it’s good enough for them….. and it was/is! It allows UV in and does not rip.
We nailed ours to the structure using U nails – so far not a single rip even after a few good storms.
Seriously – you can spend a lot of money on the top-notch materials and sure they are possibly worth it. But what we used works, for us. Keep in mind diminishing returns.
Foundations
We picked up a tip [thanks Brendon – Ed]. Lay paving stones around the outside of the greenhouse on the ground to help keep heat in and slugs out. We have yet to try it.
If you have any old paving stones they are ideal to lay down as a floor inside the greenhouse too. It needs to be comfortable to stand on but don’t fret about weeds growing through (after all, it will be near-perfect growing conditions). Just accept the odd weed and deal with them as they invade, though not with clouds of weed-killer mist!
Alternatively gravel works – maybe even make a floor out of decking wood – very flash.
The Structure
Whatever approach you take, it needs to be strong and safe. Strong enough to withstand high winds, and minus the parts that are likely to fall on your head. If it has plastic sheeting for walls it can quickly become like a sail and so the structure it’s affixed to needs to be fairly solid.
Don’t skimp on this – otherwise the whole thing may end up in the neighbour’s garden, but not in one usable piece.
For us, having decided what to put around the walls and on the roof we were able to turn our thoughts to the framing. Good-old treated fencing posts, rails and palings were an obvious choice – they are easy to buy, inexpensive compared to dressed wood, and treated to withstand the elements for enough years before a rebuild.
READ MORE about our other considerations: Planning a Hot House – Build or Buy, Size and Positioning and Planning a Hot House – Water, Ventilation & Lighting
