Non-standard greenhouses

[Phil_SK]

Although my greenhouse isn't full, I know that at some point, probably within the next five years, it will be. I have the space for another greenhouse or to extend the current one and don't foresee moving from my current address for a good long while. I've recently been starting to think about such things.

My current greenhouse has polycarbonate glazing which I really like and, partly due to the significant number of tennis balls from a nearby tennis club which hit my greenhouse, I would want any extension/addition/replacement to be of polycarbonate. I've discovered that this rather limits the choice.

One of the visiting speakers to Macclesfield BCSS last year showed a photograph of a plant taken in Alan Craig's greenhouse. I can't recall what plant it was as I was distracted by the small portion of the greenhouse wall that was visible - wide polycarbonate sheets (wider than that fitted in standard greenhouses like mine) on a wooden frame. There are a few photos on the Teesside BCSS website here (3rd row, right) and here (2nd row, left). I was intrigued but didn't really think much about how it was constructed until recently when the limitations of commercially available polycarbonate greenhouses became apparent. Now I've seen wider shot photos and I can judge the size of the greenhouse I can appreciate why the house isn't a standard one!

There are systems available for conservatory roofs that might work - like http://www.polycarbonatesheets.co.uk/en-gb/dept_58.html which has all sorts of suitable fixings http://www.polycarbonatesheets.co.uk/en ... t_327.html as you'd expect.

Anyone got any experience of these sorts of systems or thoughts generally?

Another possibility occurred to me whilst browsing one of the Tephrocactus et al. websites. Michael Kießling on his site shows the construction of a huge greenhouse which has some sort of plastic (?) 'thermal foil' roof http://www.tephrowelt.de/Sammlung/Sammlung2.htm. Anybody got any idea of what the stuff is?

And lastly, has anybody any other ideas or experience of building (or paying someone else to build) greenhouses that aren't 'off the shelf'?

[DaveW]

I have used polycarbonate twin wall sheets to roof conservatories with. I don't know if that is the same as used in your greenhouse? I have also used the glass type plastic, which is about the same thickness as greenhouse glass, but that can be a pig to cut as unless you support it well a crack can tend to run from the saw kerf, particularly on a cold day.

With the twin-wall sheet that is OK, but you have to seal the ends with special strips or the water gets in, plus dirt and algae. One problem with polycarbonate glazing is in wider sheets it used to pop out in gales, unlike glass, if not fixed in the centre as well.

I suppose it depends on how you build your greenhouse. If I remember correctly you can get aluminium glazing bars with capping strips to take it, as well as types that screw on top of timber roof spars.

DaveW.

[Peter]

Phil: you have a very large plastics firm not far from you, in Ashton -under-Lyne, Tameside. info@plasticsdirect.co.uk should get you decent advice. They do the sheets and glazing cappings,etc.

[Vic]

I recently bought quite a few sheets of 10mm polycarb Phil as a job lot, I actually spotted it on Ebay and contacted the seller who was fairly local and arranged to have a look, came away with 6 sheets of 3000mm x 600mm, plus 5 large offcuts approx. 1500mm square, all for £50 which is a lot cheaper than buying it off the shelf.

The plan is to build a large cloche, more so a small greenhouse, where I can put my larger plants during the warmer months, freeing up some much needed bench space as well as clearing the floor of large Feros etc..

I shopped around and ended up buying some glazing bars (2500mm) from Wickes, around £14 each, purely for the roof so that it's as water tight as possible. The frame will be made from timber which I'll treat myself to keep down costs.

There's a useful PDF leaflet on the Wickes website here http://www.wickes.co.uk/pcat/52sheeting

[Bill]

HI Phil,

Having built a few conservatories in my past incarnation as a builder, if you use the upvc glazing parts meant for conservatories from a reputable supplier fixed onto a timber frame as per manufacturers recommendations you will be very unlikely to have panels pop out. This is what I am looking at to replace the bodged roof on mine with one roof rather than the three roofs I have at the moment.