# My new glasshouse - finished at last



## emydura (Jun 24, 2014)

I finally finished building my new greenhouse. My old one was getting too full and was looking pretty ratty (as you can see from the first two photos). It also had poor insulation and hence the electricity costs were getting pretty steep. So in April 2013 I bought a Grange greenhouse from Sproutwell. It is 4m x 4m, so it is a good size. It has 10 mm twin-walled polycarbonate panels, so it is well insulated. I think it is the only 10 mm polycarbonate house you can get here in Australia. The frames are very strong. It is built like a tank.

Old glasshouse












It took me over a year to build the thing. I was paralysed by indecision. The biggest problem was that I had to pull the old glasshouse down in order to build the new one. So what was I to do with all my orchids in the meantime. As winter approached I felt it was too cold to do anything then so I would wait till it was warmer. But then as spring came I had lot of orchids in bud so I didn’t want to interrupt this cycle. Summer was way too hot. So before long I was back to autumn and decided I’d better do something.

So in April this year I moved all my orchids into the house. The whole lounge room was covered (much to the frustration of my wife). The spare shower and bath was full (much to the frustration of my daughter).

Our lounge room






I then pulled down my glasshouse which wasn’t too difficult, except I had a 60 cm high besser block wall which I had to knock down with a sledge hammer. That took the best part of a day and a lot of hard work.

I was hoping to be able to use the existing slab, but there were a couple of problems. Firstly it was a fraction smaller than my glasshouse and secondly it wasn’t as flat as I thought it was (see the next two photos). My neighbour/builder friend told me you have no choice but to build a new slab, which would basically double the cost of the whole project. This was way beyond my technical ability but fortunately not my neighbours. So he helped me build it. Actually it was more like I helped him. And he did an amazing job. Everyone who sees the glasshouse comments on how nice the slab is. It was a big slab too. I ordered 2.4 cubic metres of cement. The problem was the glasshouse was in the far corner of the yard and there was no easy access to it. So we had no choice but to haul wheelbarrows of cement from the front yard to the slab. I lost count of the number of wheelbarrows I moved. Maybe 30 or so. The cement truck owner said the first twenty minutes were free. After that it would cost me a $1.50 for every minute it took. It took well over an hour, maybe even 90 minutes. As anyone who has lifted cement would know, it is incredibly heavy. I could barely lift the cement off the ground let alone push it over uneven ground for 60 metres. I was totally exhausted by the end.

The problem with all this was it was taking time. I had taken a week off work to finish the whole thing, but building a slab takes time. This wasn’t helped by the fact it was Easter, and the shops were closed for several days. So we couldn’t start the slab till mid-week. It took a day to setup and a day to lay and then we had to wait for the cement to dry. By the time it was finished I had barely started to build the greenhouse and then had to go back to work. So I had to wait for the weekends to complete the glasshouse. I couldn’t get an electrician for two weeks. So instead of a week, it ended up taking about 6 weeks. Meanwhile I had to keep watering my plants, which meant carrying every plant outside. And then take them all back into the house. It was too cold to leave them outside. Once a week I did this. The plants really had to suffer a bit of neglect during this period. 







Ready for the cement. You can see how the large gradient going from right to left. It was about a 6 or 7 cm drop.





Here is the glasshouse partially completed.






Canberra is the coldest city in Australia, so I really needed to insulate my glasshouse well. Especially as it was much bigger than my old one. So I fitted industrial strength bubblewrap which is designed for greenhouses. I used 30 x 1.5 metres of bubblewrap. I just used bolts and nuts and big washers to hold it in place. Based on JohnM’s advice I also put sheets of polystyrene under the slab to insulate the floor. I think it has worked very well. Despite being way bigger in volume, the heater seems to be on way less than previous. In my old glasshouse, when the heater went off I would just watch the thermometer plummet before the heater came quickly back on. In the new glasshouse, the temperature drops very slowly. You have to wait much longer for the heater to kick back on. 

The other advantage of better insulation is that the new greenhouse is much better in retaining moisture. That is, it is much more humid. You may have remembered my problems with my old glasshouse where in winter the humidity levels would get very low during the night (down to 30%) and I was constantly having to water my plants as they were drying out so fast. I just put it down to the heating drying the atmosphere. I think it was Ray who said the problem was the insulation in my glasshouse. He was absolutely right. Now that my glasshouse is better insulated the humidity at night during this winter is always above 80%. So I’m currently only watering my plants once a week. 






An outside photo of the finished glasshouse. The shade cloth is aluminet. 






Looking inside





As you can see I now have plenty of room. I can fit more benches in the middle as well as in the back corner. So I can fit in a lot more orchids. And if I run out of space I can order another 2 metre section and append it to the existing one. I believe 20 metres is the limit. You can see my fogger mounted at the top of my glasshouse. I’m loving the slab floor. I was going to put gravel or something over it. I was worried a concrete floor would mean low humidity but that couldn’t be further from the truth. The slab is just neater and easy to clean. 










Unlike my old glasshouse I have built this one east to west. This has meant that it is heating up much better on these cold winter days. On a sunny day, it would reach about 23oc by about 9.30 AM and quickly gets to around 27-28oc. It stays around the mid 20’s right through to about 4:00 pm. So for a good 7 hours or so the temperatures are really nice and warm inside. Outside the current temperature is around 13-14oC. My old glasshouse would be around 5oC cooler and would only be warm for a short period of time. The big test may be summer where the temperatures get very hot. It may be a struggle to keep it cool enough. I will need a lot more shade cloth. I will cross that bridge when I come to it. But at the moment I am very happy with the way it is warming up on these cold winter days. I think the multi-floral Paphs will also be happy.

It was a long drawn out frustrating process but I now have a glasshouse I use to dream about.


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## Lmpgs (Jun 24, 2014)

Enjoy your new greenhouse. I hope you fill it with orchids soon.


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## Stone (Jun 24, 2014)

Congratulations David! Its very nice. Now you need one for the warm growers and another for the cool...:evil:


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## Ozpaph (Jun 24, 2014)

Wow David, that's awesome and a great 'walk through' the project.
You have SO much room now!
You might need something on the floor (ie industrial rubber matting) as the wet concrete will grow algae and get very slippery, I think. Be careful!


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## emydura (Jun 24, 2014)

Stone said:


> Congratulations David! Its very nice. Now you need one for the warm growers and another for the cool...:evil:



I do need a cool house. I might reuse my old glasshouse for this purpose. A bit small though for all my Cymbidiums and Dendrobiums. I was thinking at the end I could have bought another 4 or 6 m section and attached it to my warm house. That is, you walk through the cool house and open the doors into the warm house. Maybe one day. 



Ozpaph said:


> Wow David, that's awesome and a great 'walk through' the project.
> You have SO much room now!
> You might need something on the floor (ie industrial rubber matting) as the wet concrete will grow algae and get very slippery, I think. Be careful!



Thanks Stephen. I'll see how it goes. Eventually I will put a bench down the middle so there will only be a small passage way. If it gets slippery, I'll do as you say.


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## bigleaf (Jun 24, 2014)

Congratulations !


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## fbrem (Jun 24, 2014)

that is a beautiful growing area, congrats


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## eggshells (Jun 24, 2014)

Very nice, I am jealous. I particularly like the extra metal that separates the aluminet from the roof. Does it hold strongly against winds?


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## tomkalina (Jun 24, 2014)

Very professional looking. Now to add a few (?) plants


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## NYEric (Jun 24, 2014)

emydura said:


> Our lounge room



Welcome to my world! 

Good job, that GH would be the envy of many of us; thanks for sharing.


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## Justin (Jun 24, 2014)

nice!!!


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## naoki (Jun 24, 2014)

Wow, nice greenhouse! The concrete slab is shiny, it looks like you polished it! Are you heating it with electric heater? That must be pretty expensive.


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## fibre (Jun 24, 2014)

Gratulation! What a nice greenhouse!
By reading your story I can feel my arms becoming longer and longer while pushing the cement. What a horrible job for an untrained body like mine.


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## Clark (Jun 24, 2014)

Fantastic!


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## emydura (Jun 24, 2014)

eggshells said:


> Very nice, I am jealous. I particularly like the extra metal that separates the aluminet from the roof. Does it hold strongly against winds?



The shadecloth frame is drilled into the glasshouse frame, so it is pretty sturdy. It actually was very windy yesterday and handled it fine. Funny thing with that shadecloth frame. I finished building the glasshouse and then started thinking about installing the shade cloth. I opened the box and it hit me. I really needed to screw in the shade cloth frame before I assembled the glasshouse. I had to screw in four sections on the top of the roof which is very high. So I had stand on the top of the ladder in the greenhouse through one of the windows and at full stretch holding a heavy drill make four screw holes. And I’m not great with heights. It would have been so much easier if I had preplanned.
Actually the whole building of the greenhouse was a bit like that. The instructions were terrible and it was very easy to put sections around the wrong way. I ended up having to spend a full day undoing all the mistakes we had made. I ended up with all these pieces that were left over that I had no idea what to do with. I assume they weren’t important. The company says a single person could put this greenhouse up in a couple of hours. Yeah, right. 



naoki said:


> Wow, nice greenhouse! The concrete slab is shiny, it looks like you polished it! Are you heating it with electric heater? That must be pretty expensive.


I had just watered the greenhouse before I took the photo, so it is reflecting the light a bit. Still it has a very smooth surface. Yes, I use an electric heater. We will see how the costs go. It should be cheaper than my previous glasshouse. If the winters stay as warm as the current one it won’t be so bad. 


fibre said:


> Gratulation! What a nice greenhouse!
> By reading your story I can feel my arms becoming longer and longer while pushing the cement. What a horrible job for an untrained body like mine.


Believe me Chris, my body is as untrained as yours. While I’m tall, there is little muscle on my body. I’m pretty lanky and not designed to lift such weights. The first few wheelbarrows felt OK. But then fatigue set in. While carrying a load of cement, I also cracked the wooden handle of my neighbour’s wheelbarrow. So added to all my costs, was a new wheelbarrow.


I forgot to mention to those Australians who might buy this glasshouse. You can see inside the glasshouse, there are two supporting poles in the centre. The instructions said these were optional and were only required where the roof had to support a heavy snow load. So I had no intention of using them. However, without them I found that the centre of the roof sagged badly and hence decided that I better use these supporting poles. I would have preferred not to.


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## 17andgrowing (Jun 24, 2014)

Congrats! That looks great.


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## SlipperFan (Jun 24, 2014)

That's beautiful, David! And so much room for more plants! Congrats!


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## cnycharles (Jun 24, 2014)

very nice


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## NYEric (Jun 24, 2014)

emydura said:


> I forgot to mention to those Australians who might buy this glasshouse. You can see inside the glasshouse, there are two supporting poles in the centre. The instructions said these were optional and were only required where the roof had to support a heavy snow load. So I had no intention of using them. However, without them I found that the centre of the roof sagged badly and hence decided that I better use these supporting poles. I would have preferred not to.



That's silly. Looking at the unsupported span i think its obvious that the supports are necessary. I think they can only be replaced with a top truss. Good choice to use the poles.


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## abax (Jun 24, 2014)

Gooooood job. As a home greenhouse builder, I appreciate all your effort
and everyone needs a gofer to hand 'em tools rather than climb down a
ladder to fetch things. I have a rough finished concrete floor and algae
does build up and it's VERY slick. Keep a one gallon pump sprayer around
with a mixture of bleach/water to spray those slick spots. Stay upright and enjoy your new greenhouse!


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## kellyincville (Jun 25, 2014)

Sodium percarbonate is also great for slippery floors. I use it at work (where bleach is a big no no).


Sent from my iPhone using Tapatalk


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## DavidCampen (Jun 25, 2014)

Physan or any of the similar quaternary benzyl alky ammonium compounds such as are sold for killing algae in pools and hot tubs does an excellent job of eliminating algae. For Physan, one part in 500 of water is sufficient.


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## JeanLux (Jun 25, 2014)

Very cool David!!!! Great job building it up; you know what it is worth then , even with help of a kind neighbor!! I imagine your plants will develop even more beautifully now!!!! Jean


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## eggshells (Jun 25, 2014)

emydura said:


> The shadecloth frame is drilled into the glasshouse frame, so it is pretty sturdy. It actually was very windy yesterday and handled it fine. Funny thing with that shadecloth frame. I finished building the glasshouse and then started thinking about installing the shade cloth. I opened the box and it hit me. I really needed to screw in the shade cloth frame before I assembled the glasshouse. I had to screw in four sections on the top of the roof which is very high. So I had stand on the top of the ladder in the greenhouse through one of the windows and at full stretch holding a heavy drill make four screw holes. And I’m not great with heights. It would have been so much easier if I had preplanned.
> Actually the whole building of the greenhouse was a bit like that. The instructions were terrible and it was very easy to put sections around the wrong way. I ended up having to spend a full day undoing all the mistakes we had made. I ended up with all these pieces that were left over that I had no idea what to do with. I assume they weren’t important. The company says a single person could put this greenhouse up in a couple of hours. Yeah, right.



Yes, they always say that to sell more products. Anyways, thanks for the idea. I saw something like that here but no shade cloth frame. Thanks!


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## papheteer (Jun 25, 2014)

Congratulations!! It's a great looking Glasshouse. Very neat! I hope you have lots of fun in it! Your plants will grow EVEN better!


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## Justin (Jun 25, 2014)

do you have a backup heater in case the electricity goes out?


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## Heather (Jun 25, 2014)

Wow, congratulations! Just beautiful!


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## orchid527 (Jun 25, 2014)

Job well done!!! I really enjoy it when members take the time to document new construction and changes to existing growing areas. It is a great opportunity learn new tricks. Thanks.

Mike


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## emydura (Jun 25, 2014)

Justin said:


> do you have a backup heater in case the electricity goes out?



No, I don’t have any other source of energy Justin. I would have to get a generator or something. I have insulated the glasshouse to such an extent that even if the energy went off on the coldest night (around -5oC), I would expect the temperature inside the glasshouse to still be well above freezing. I think short term drops in temperature to 4 or 5oC wouldn’t do much damage. Power blackouts may be more of a problem in summer when it is really hot. If there are no fans going or the fogger cooling the glasshouse, it could overheat.

I’m waiting for the battery storage of solar created energy to become more affordable. When that happens, power blackouts won’t be a problem. People are implementing self-sustainable solar systems now but they currently are not cost effective.


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## abax (Jun 25, 2014)

Bleach is cheap!


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## SlipperFan (Jun 26, 2014)

abax said:


> Bleach is cheap!



And effective!


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## SlipperKing (Jun 27, 2014)

I finally got my wish! Congratulations David for a job well done! If I'm not mistaken you built on top of your old GH slab, correct? Do you have space to re-build your old one?
I don't see any exhust vents or fans. Do you have plans for installing one or two later? In my neck of the woods they are a must for cooling, summer and winter. They will also help moderate the humidity issue that was mentioned. Did you mention this was twin-wall polycarbonate skin covering the frame?


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## emydura (Jun 27, 2014)

SlipperKing said:


> I finally got my wish! Congratulations David for a job well done! If I'm not mistaken you built on top of your old GH slab, correct? Do you have space to re-build your old one?
> I don't see any exhust vents or fans. Do you have plans for installing one or two later? In my neck of the woods they are a must for cooling, summer and winter. They will also help moderate the humidity issue that was mentioned. Did you mention this was twin-wall polycarbonate skin covering the frame?



Thanks Rick. Yes, I built the new slab over the top of the old one. There isn't enough room to put the old glasshouse on the new slab. I have room in the rest of the yard although there is no slab or such. Although I don't think I would go to that much trouble. There is also a bit of a slope so I would need to flatten out the base, which just makes it a bit complicated. I have a spot I might put it. I would just use it for cool growing orchids.


Yes, it is twin-walled 10mm polycarbonate. Amazingly strong stuff. It seems unbreakable. It is a pity they don't seal the ends. I'm not sure if they do for other polycarbonate panels. Moisture and insects get in the 10mm gaps. So effectively I have three layers. - the twin walled polycarbonate, the large gap (4 cm or so) between the polycarbonate sheets and the bubble wrap and then the bubble gaps in the bubble wrap itself. It is not air tight but still it is very well insulated, especially when you also consider the polystyrene sheets under the floor. I'm pretty happy with the humidity levels now Rick. They seem appropriate for the temperature. When the glasshouse gets to about 25oC the relative humidity drops to the point that it turns on the fogger.


I have one large vent with an automatic opener attached (see photo below). It is only set to the minimum opening level at the moment, which is fine for winter. The maximum temps I'm getting on a nice sunny day is 28oC. In summer I may need to open the window to the maximum. I might also need to setup another automatic vent on another window (I have 4 windows, although 3 are unusable at the moment as they are covered by bubble wrap). I'll suck it and see.

I'm sure everyone is aware of these automatic vent openers, but if you aren't they contain wax which when it expands because of heat pushes open the window. When the temperature cools, the wax contracts and hence closes the window. So it requires no electricity. Works like a charm.


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## Stone (Jun 28, 2014)

I had those wax openers on my old g/h. They worked for about 5 years from memory. When they stopped I just left them because they were too high to reach. But I found the evap cooler removed enough of the warm air anyway.


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## emydura (Jun 28, 2014)

Stone said:


> I had those wax openers on my old g/h. They worked for about 5 years from memory. When they stopped I just left them because they were too high to reach. But I found the evap cooler removed enough of the warm air anyway.



The one on my old glasshouse was still going well after 12 years. I'm not sure what could go wrong with them as they are a pretty simple design. But I'll keep a closer eye.


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## Ozpaph (Jun 29, 2014)

they probably leak the wax, then fail.


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## monocotman (Jul 2, 2014)

I've used these vents in every greenhouse I've had.
Bayliss sell these in the UK and they tend to fail after a few years.
However they sell replacement tubes of wax and they're pretty easy to fix.
David


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## emydura (Jul 23, 2014)

Justin said:


> do you have a backup heater in case the electricity goes out?



We had a blackout last night between 4 AM and 6.30 AM. It was a cold frosty winter night. Pools of water were frozen solid. But the lowest the temperature in my glasshouse went down to was 9.6oC. A bit cool for the multi Paphs but nothing that would do any damage. Nights can get colder than last night, but not significantly so. At its coldest it is clear my glasshouse would be well above freezing, maybe around 6oC or 7oC, which wouldn't pose any short term problems in the case of a disaster (which is rare anyway). It is good to know all the insulation I have done is working well. It has paid off already. I can sleep easily now.


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## NYEric (Jul 24, 2014)

Bad and good news.


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## SlipperFan (Jul 24, 2014)

Being able to sleep at peace is good!


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## Ozpaph (Jul 25, 2014)

My multis grow outside and we've had a couple of mornings at 4-7C recently - no problems.


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## Stone (Jul 25, 2014)

Ozpaph said:


> My multis grow outside and we've had a couple of mornings at 4-7C recently - no problems.


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## Ozpaph (Jul 25, 2014)

Its what they get used to, I think. And its for a few hours at most then its 20C again!


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## emydura (Jul 25, 2014)

Ozpaph said:


> Its what they get used to, I think. And its for a few hours at most then its 20C again!



I guess that is the difference between Brisbane and Canberra. Your minimum temperatures climb very quickly (so the plants are not cold for long) and your maximum temperatures will get much warmer (which I think is important).


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## eteson (Jul 25, 2014)

Nice work! Congrats.
You can always install a small heater just in case...


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## emydura (Jul 25, 2014)

eteson said:


> Nice work! Congrats.
> You can always install a small heater just in case...



I have a heater installed. The heater keeps the minimum temps going below 14 or 15oC. But if I have a blackout like occurred the other night, I have no plan B. But it would appear for the short period that this may occur, this won't be a problem.


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## eteson (Jul 25, 2014)

Sorry I mean a small alcohol heater.


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## Migrant13 (Jul 25, 2014)

Thanks for sharing the whole process and best of luck with your new greenhouse. You and your neighbor did an excellent job. Any $$$ left for plants?


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## emydura (Jul 26, 2014)

Migrant13 said:


> Any $$$ left for plants?



A little bit.  I bought a few the other day actually. I have a lot of room to fill. I need to get some more benches now.


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## Ozpaph (Feb 10, 2015)

Time for an update, please, David. How hot did it get over summer? Do you have a cooler or just misting/fogging?
I have to build a new orchidhouse and am contemplating a 'closed' house this time, but will have to heat and cool!


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## SlipperFan (Feb 10, 2015)

Please have a back-up plan. Nothing like losing plants do to a weather disaster.


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## Ray (Feb 10, 2015)

If you have no other heat source, drag your gas grill into the GH...


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## MaryPientka (Feb 10, 2015)

Congratulations!


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## abax (Feb 10, 2015)

Two pieces of advice that you didn't ask for 1. your concrete floor will get VERY slick and you need to keep it
very clean or "you'll break your neck" as all mothers say
2. Get a gas generator for a backup system in case of
power failures. Your greenhouse is not so large that you'd have to have a large generator so less expense.


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## emydura (Feb 11, 2015)

Ray said:


> If you have no other heat source, drag your gas grill into the GH...





abax said:


> Two pieces of advice that you didn't ask for 1. your concrete floor will get VERY slick and you need to keep it
> very clean or "you'll break your neck" as all mothers say
> 2. Get a gas generator for a backup system in case of
> power failures. Your greenhouse is not so large that you'd have to have a large generator so less expense.



Yes, parts of it are getting a bit green although not the areas I walk on. They tend to be hidden under benches.

The greenhouse is so well insulated, that even on the coldest winter night the temperature wouldn't get low enough to do any damage. Not in the short term anyway. A power blackout on a hot summers day would present more of a problem. It would get very toasty if the fans and fogger stopped working.


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## Ozpaph (Feb 11, 2015)

David, your summer experience??? Thanks


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## emydura (Feb 11, 2015)

Ozpaph said:


> David, your summer experience??? Thanks



It has been a little tough at times Stephen. This is definitely a warmer greenhouse than my old one. It has been designed to cope with Canberra's cold winters which it has done really nicely. The flip side is it can get a bit too warm in summer - regularly temperatures can reach 34oC or more on hot sunny days. I have had to put an extra layer of shade cloth on. I have two roof vents operating. The humidity stays above 70% so the conditions aren't too oppressive for the plants. The big problem I have had is my fogger on two occasions has stopped working on really hot days and that has caused some grief. The temperature has climbed and the humidity has plummeted. I think the bearings in the motor are playing up and occasionally the motor won't start. I have just received a new motor so I will have to replace the old one. The fogger has been working really well for the last few weeks so it seems a bit intermittent.


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