greenhouse construction

[wadave]

I've been meaning to post some pics of my greenhouse I built about 12 months ago and was inspired by matti's post and the replies he received.... all 8 pages of it.

Here the front door, base and walls have been erected.

I started this from scratch by making a plan, estimating the lengths of timber, working out the angles, and sourcing all the other materials such as plastic film, shade cloth, nails, retic timer and pipes, solenoid etc, evap cooler, humidifier, front door, screws and the like.

I got dad to help me start the roof sections but the rest I did by myself. Yes even installing the plastic film which was a real b@#*h because everytime I got it started the wind would blow it off again. I managed to figure out how to do it and got away with only a small tear. The hardest part was attaching the plastic on straight and doing it quickly enough before a big gust took hold to rip it off leaving me with big gashes.

Here I've finished the frame and started the cross bracing. Once this was completed the whole structure was rock solid, quite a good feeling really.

[wadave]

Some of you may have seen some of my replies to post to greenhouse questions talking about the reflective shade cloth called Aluminate.... well here it is. You can see it has a metallic appearance and does reflect light which as a result reflects heat. You can see the evap cooler, the power box on the left and the front door is a second hand security screen I got at the dump for $10.

In this photo you will notice the flap of plastic at the top of the roof that hangs loosely down. I left this open last summer to ensure the excessive heat would escape easily but found it was difficult to keep humidity above 40% even with the evap cooler and humidifier. This winter I closed it up for two reasons, firstly to stop high winds during frequent storms pressurising the GH causing the plastic to tear away from the frame and secondly to test how well my evap cooler will cool and measure the humidity. So far this winter every time I go inside it is like stepping into a highland rainforrest with swirling mist.

This is the RHS from inside the GH, you can see my bath tub bog. I was using this for my sarra seedlings I germinated last year but they've since been moved to seed trays and the bog is now awaiting a top up with more medium so I can plant it out with some of my mature sarras, cephs, drosera and the like. I can't wait to see it finished.

The RHS, photo taken from outside. You can see a bit of the retic up near the roof. I'm thinking about painting the pipes white or wrapping them in some insulating foam to reduce heat absorbtion during summer as the water does heat up quite a bit and was affecting my cobras.

[wadave]

I only finished the shelving on this side a few weeks ago as I have written and article for the VCPS newsletter and I needed to send some photos of the finished GH. It is already starting to fill up with plants.

In this photo you get a sense of how well the humidifier works with the mist floating around, even with the flap open at the top of the roof and the door open.

Close up of the humidifier and evap cooler, the bucket is supplied with water from the garden tap via a toilet cistern float valve. Those ultrasonic humidifiers can use quite a bit of water and I don't want it to run dry. A few days ago the evap cooler developed and earth somewhere on the water pump and tripped the circuit breaker on the house so I had to go source another cooler which was surprisingly difficult as it is winter and all the second hand shops stop selling them until October so they don't have to discout!!! The unit I found was better than my current model in that the water reservoir is deeper so I can now install a float valve here to. Last year I found it very difficult to keep a constant level of water in the old cooling unit. My setup was simply a drip line from the retic pipes to the cooler and I would manually adjust the rate of water depending how full the reservoir was at the time I checked the GH. Secondly the new unit has a flap you can open and close at the front, used to fill the reservoir that allows me to insert ice packs on those really hot days to get extra cooling. The old one had a moulded funnel arangement at the back that didn't give open access to the reservoir, which you will see in the next photo.

Notice the black drip line that runs into the back of the cooler at the bottom of the filter. This is the funnel like opening I was talking about before. So due to this unexpected electrical fault I have been able to find a new unit that solves my problems of how to automatically maintain the water level to the unit and how to get extra cooling during the hottest days of summer. Plus I've already got plans for the fan and the water pump in the old unit.

I've used thumbnails in the hopes the post loads quickly and it was such a big post I wan't sure how much space I could upload in one go. I even got kicked off and lost some of my work because my session time expired... I went to watch some tv and have dinner.

I hope this is inspirational to those who, like me, just don't know where or how to start.

Having a greenhouse is magic and the only problem is you run out of space so quickly. I've already organised to import lots of different sarras that aren't available in Oz yet that I'm sure all available space is gone.

Dave.

[wadave]

One for pitcherfreak,

You asked matti about heli's and I can say for a fact they love it in my greenhouse. They get plenty of overhead watering during summer, one minute every hour during the day. This is reduced to two or three times during winter depending on how much cloud cover affects evaporation.

I've currently got minor hairy (pulchella apparently), heterodoxa x minor, tatei, and tequila all growing strongly. None of my plants sit in trays and I use tap water which is around 120 - 130 ppm but any salts are continually flushed through the post.

My cephs just love it in there along with sarras, some highland neps, currently the list is: maxima, ventricosa, maxima x talengensis, and two new additions: rajah and hamata which are only out of tissue culture a few months so are quite small.

I've also got some of my pings sitting in a dryer part of the GH but they seem to love the humidity.

Dave.

[matti]

Timber frame! C'mon Dave!, it is a very good job. What are you growing in there?.

[pitcherfreak]

Thanks Dave.

Love the greenhouse. Still have heaps of work to do on my house. Am going to have to strengthen my roof have found another of my make of house with no roof. Out of curiosity how warm do your helis get in your house (Would lv to grow some in mine), they're hard to get in N.Z.

[wadave]

Hi Matti,

I've got sarra's, heli's, cephs, cobras, pings, some drosera that came in some of the plants I've bought and a binata multifida, plus some neps all highland.

The timber is all second hand jarrah, 3 x 3, which I bought for $2 a meter, the shelving slats are made from an old jarah fence I salvaged from an old house we renovated so the whole thing is rock solid.

Jarrah grows naturally here in WA so it is quite cheap to buy and all the old houses built in the 50's were made almost exclusively with it which makes the stuff easy to get hold of second hand.

Thanks for the compliment by the way.

It gives me a great sense of achievement every time I go for a visit which can be several times a day as I have the home office.

To answer your question pitcherfreak, last year the temps rarely topped 35 deg C with the top flap open and the evap cooler going on days well over 40. The heli's thrived in this environment which I put down to the regular overhead watering. My pulchella and the heterodoxa x minor have both doubled in size in the last year and have no problems flowering.

I am doing the second half of the experiment this year by closing up the flap and installing the wax operated vent unit. This one is adjustable to open from 16 - 25 deg C. If it gets too hot and the evap can't cope I will have to install an exhaust fan to draw out the really hot air from the top of the GH.

Having the flap open last year meant the temperature was manageable but it was difficult to keep humidity above 40%. Even so my plants seemed to like it, the only ones that didn't appreciate the fluctuations in humidity were the sarras which would produce some slightly curved pitchers.

I want humididty to be around 60% or more this year to give the sarra's a better environment but if the temps get unmanageable I will have to sacrifice perfect sarra pitchers for cooler temps until I can afford to install a decent sized wet wall and fully seal the plastic film.

Dave.