Norfolk standard greenhouses and ventilation?

[kingkano]

Long time reader rare posted here Read plenty of old threads on greenhouse selection dilemma! Now facing the same thing myself.

The cheapskate in me is considering the Norfolk standard PVC clingfilm style ones. But my main worry is how on earth do people ventilate them? You grapes that have them what do you do? Just open the door?

How long does the PVC sheet last? I am figuring 3 or 4 years before it disintegrates?

Otherwise I am comparing the Waltons and Gardman polycarb models (8x6 in size). Apparently the Waltons is slightly smaller and doesnt use glazing clips, it just slots into the frame.... sounds both good and bad. Waltons does have 2 roof vents as opposed to 1 on Gardman and its ever so slightly cheaper. Cant afford toughened glass and wouldnt want to get horti glass as have a almost 1 year old running around!

Anybody got a Waltons? Understand either one will need some extra securing (more clips, silicone, etc) quite happy to undertake that.

Many thanks in advance for any advice.

[King Carrot]

Personally, having had a Norfolk product I would never use them again. We had a Gardenroom 8 with polycarbonate and twin wall "glazing". Besides the well known construction drawings and the overall flimsiness (the sliding window blew out and broke in the first hour, following its completion and I replaced it with a wooden framed opening window) we weren’t too disappointed when a few months later the wind blew from an unusual direction and it just disintegrated, the doors and the polycarbonate sheets just tore out of the frame – have photos too if you’re interested and a lot of bits of poly carbonate sheeting and bits of frame in the shed


For the same price as a Norfolk you can build a wooden framed structure with as much ventilation as you want and 5 year life (which could last 7 or 8 years) polytunnel plastic to cover it with.

[kingkano]

Thanks for the reply. Yes I have read far too much bad press on the Norfolk polycarbs. Considering they are not much cheaper than others that are better quality and have vents etc I am not even considering it.

For the same price as a Norfolk you can build a wooden framed structure with as much ventilation as you want and 5 year life (which could last 7 or 8 years) polytunnel plastic to cover it with.

Maybe YOU could lol. I'd need to buy some decent tools first and I am not confident in my carpentry abilities. Things like doors and vents etc I just can't imagine how I would do very well. I have considered it though! Although I'd be more inclined to use wood and polycarb panels rather than sheeting (panels last longer and bad experience of cats squirrels etc tearing my sheeting).

Just about managed my Geoff Hamilton style hoop cloches if I am honest.

[Potstubsdustbins]

I have a Waltons twin wall poly carb 8 x 6 erected summer 2009, there are some draw backs but non which can't be overcome.

Delivery was spot on more or less to the hour.

Building was a real chore, in reality 3 pairs of hands needed, though I suspect that two people that have done it a few times would make it look easy. The instructions wern't that good, just about adequate. You will need a large flat area for the construction as everything is very flimsy until all the component parts are assembled. Any wind and you will find yourself with a very large kite.

The glazing panels are a tight fit and need care I used `potable` silicon grease to smooth the way. The base is a must have, however the four corner pegs supplied to fasten it down are useless, fortunatly I was fixing to a concrete base so drilled out the fixing holes to take 35mm long coach bolts and used those to secure the structure.

The opening windows need adjustment after fixing but then seem fine. The sliding door has no catch I used magnetic strip the same as what is used on shower cubicle doors.

Finally I used clear silicone to seal and fix the glazing panels. So far I have had no problems with either structural integrity or looseing glazing panels.

One final tip if you have a battery drill get the correct size socket and nut spinner it will save hours.

All in all 7 out 0f 10.

Hope this helps Colin.

[kingkano]

Thanks alot Colin thats very useful feedback. It seems all the cheap greenhouses have dreadful instructions!

Like you I am fixing onto concrete or perhaps a small breezeblock wall. Thanks for the tip there.

When you say the windows needed adjustment? In what way?

Thanks again.

[Kristen]

Bit left-of-field, but have you considered second hand off eBay / freecycle?

No instructions, but if you take it down you can take loads of photographs and be clear how to reconstruct.

You should get plenty for your money that way ... but you will have to wait until something suitable comes up and you have to be prepared, and able, to go and get it.

[Potstubsdustbins]

KK,

Just a bit of fiddling up & down side to side etc, just to make sure they are snug in their openings so that no wind can get under them. They do have a good strong stay with a thumb nut to lock them in the required position when open.

Colin

[kingkano]

Bit left-of-field, but have you considered second hand off eBay / freecycle?

No instructions, but if you take it down you can take loads of photographs and be clear how to reconstruct.

You should get plenty for your money that way ... but you will have to wait until something suitable comes up and you have to be prepared, and able, to go and get it.

Yes I had considered but in my area on freegle they are like hen's teeth, if one does come up it seems to go within 10 seconds! Guess too many down here are getting into GYO lol. Watched ebay for a few months but most stuff went into the 150/200 bracket at which point I think better off getting new (and most of it is glass so would need reglazing for me).

Thanks for the suggestion tho!

Thanks for that Colin. It was a close call but I got the Gardman 6x6 in the end - fitted my space better and I found a good deal with a louvre vent and auto opener for the roof and some other goodies. Have got it quarter built so far - quite a job!

[SarzWix]

I have 2 Norfolk Standard's, and they are nothing like the polycarb panelled ones. The cover is very like a polytunnel cover, with the ends buried in a trench, nothing moves them. One of mine is more or less in a windtunnel with the wind racing acriss a school field before being funneled between hedges to hit my greenhouse, but it's stood firm for 4 years now.

So. Ventilation

As long as you get 6x6 or bigger, they have a window at the back which lifts up like a roof light on an ordinary greenhouse. We've managed to fit an automatic vent-opener to ours with the help of an extra bracket. This is good enough to keep it cool til you can get there to open the door. I also have, at ground level underneath the window, a slit cut in the plastic and a piece of drain-pipe inserted; this is largely to provide the correct ventilation for the gas heater I use, but also helps later on in the summer.

So it is possible to set up automatic ventilation, but if you're going for the 12ft one like mine, then I would say it's just 'adequate', not perfect and I'm looking for a way to install this: Solar-Powered Vent Possibly by putting in just one polycarb panel, secured with plenty of silicone! For the 6x6 and 6x8 sized greenhouses, I think the door and the window will provide enough ventilation.