Advice on building a greenhouse

[keithrs]

I think it may be time to build a greenhouse!!!!

I'm looking to build a small one... 15x15 which should do for now but have room for expansion.

What I'm looking for is advice from the folks that have or had a greenhouse on what they like about there greenhouse and what they would do different.

I think since I live in SoCal, I'm going to go with a single layer of 6 mil plastic and wood frame. I'm going to add a cooling pad and a if needed a ac unit. Ill also add a small space heater. Temps rarely go below 40 in the winter.

What do you guys think?

 

[ehanes7612]

i found that 6 ml weathers and brittles quicker than 4ml or even 3ml , i have a two layered 4ml with 4 inch space in between each layer. I have a wood frame that works perfectly ..i used the standard hem fir studs (4x 4 at the base and 2 x 4 for sides and roof)..construction grade. If you rarely get below forty one space heater might do it but you might want a second as a backup..if it did get below forty, one space heater (i am assuming its the 15oo watt type) wont adequately heat a 15 x 15 space). good luck!

 

[mormodes]

I read and re-read then read again the guides and plans on the Sundance Supply web site and am very happy with the GH I designed and built for a fraction of the cost of a kit.

 

[ehanes7612]

yeah mine only cost two hundred dollars (12 x 9 with ten foot to six foot slant roof)..here are photos of mine ,hope it helps (i have it slanted because of the apple tree above it and because we get snow, but you wont have that problem)..this design is ultra sturdy against the wind

i also dont have the bottom wafer board skirt anymore..was a temporary fix until i wrapped the bottom with plastic

...

this pic was before i put the outer layer of plastic on the roof but you get the idea..i dont have a vent , which i will need this summer but you being in s. california..you will definitley need one most of the year..the temps can climb to 100 degrees inside even if its only 60 degrees outside..i also use 70 % shade cloth this time of year

 

[likespaphs]

i found that 6 ml weathers and brittles quicker than 4ml or even 3ml....

even uv stabilized stuff?

 

[ehanes7612]

even uv stabilized stuff?

i wouldnt know..what i used was the plastic you buy at homedepot and probably isnt meant to be used for long term..another thing to be concerned about is how you attach the plastic..the more holes you put in the plastic, the more chances the plastic will shear from the chance of it ripping at the hole..wrapping the greenhouse and attaching the plastic at the ends works pretty well

 

[Stone]

The favorite thing about my new g/h......Shade you can roll up and down.
Oh, and Keith, build it twice as big (NOW!!) as you think you need it!!!

 

[Candace]

Keith, make it as attractive as possible or your neighbors will hate you.

 

[SlipperFan]

Keith, make it as attractive as possible or your neighbors will hate you.

Good point! And that would not be pleasant!

 

[keithrs]

Keith, make it as attractive as possible or your neighbors will hate you.

I don't have to worry much about neighbors.... LOL Thats the good thing about having parents that have lots of land!!!

Thanks for the comments so far everyone!!!!

So, Anyone have ideas on building a cooling pad?


Here is a small 8x8 that my dad used to start seedling for the garden. Some punk kids cut the sides with a knife several yrs. back and it is now a shed....Well kind of....

I think a 15x15 will be big enough for a while.... I want to move to OR. in the next two yrs. Thats when I'll build a nice and big one!!!!

 

[mormodes]

Farmtek.com sells cool pads IIRC. Then just a rain gutter on top and bottom, a pond pump for water circulation and large bucket of some sort to use as a reservoir. I think a float in the bucket helps as a shut off if you have it hooked to a water supply.

 

[keithrs]

So, Doing research on cooling pads I have quite a few options. I'm going to go with a 6" pad but I'm wondering how tall and how long of a pad I should use? I plan on putting alum-net over the house.

Also, Should I stick with a 15x15 or should I go with a 10x20?

 

[Yoyo_Jo]

I don't have a greenhouse, but I've never met a single serious orchid grower who had too much room. Go BIG!!! Looking forward to seeing your construction progress!

 

[keithrs]

Any one have advice on what shade aluminet I should use for Masd. and such? I was thinking 70%.

 

[ehanes7612]

i use 70 % for paphs and dendrobiums...i would imagine you want 80% for masdies , especially in san diego

 

[Rick]

I built my own wet pad. Similar to Mormodes description I used rain gutter for the collection and lower support draining to a sump. A pond pump with hand drilled pvc spray bar dribbles water on the top of the pads.

I used 2' tall pads, 4" thick (fits perfectly in the rain gutter). My GH is 12X12 and the wet pad covers about 8' of the back wall.

To get air through it, most people use their basic ventilator fan mounted on the opposite end of the GH from the wet pad. But this means you can only use the wet pad for summer cooling (since you don't want to drag cold winter air through the GH in winter)

Since TN winters are dry, I mounted box fans on the front my pads, and built a louver system so that I can recirculate the air through the pads in the winter for humidification, but during the summer it brings in outside air for more efficient cooling. I get efficient humidification year round and decent cooling in the summer.

 

[tenman]

i use 70 % for paphs and dendrobiums...i would imagine you want 80% for masdies , especially in san diego

Actually, masdevallias take - and need - quite a bit of light. About cattleya level would be right. George Fuller, who spoke at our 2001 Mid-American, grows them in almost full sun in NZ upside down hanging out the bottoms of pots for better flower viewing. Is is a common misconception that since they are cool-growing they are shade-loving. Not so.

Your shade % is probably more about how well you can cool than too much light. I have gone to 30% aluminet here in Ohio (and would go with 20% if thought I could cool sufficiently), where admittedly we don't have quite as much sun as you do there in my idea of heaven.

 

[keithrs]

I built my own wet pad. Similar to Mormodes description I used rain gutter for the collection and lower support draining to a sump. A pond pump with hand drilled pvc spray bar dribbles water on the top of the pads.

I used 2' tall pads, 4" thick (fits perfectly in the rain gutter). My GH is 12X12 and the wet pad covers about 8' of the back wall.

To get air through it, most people use their basic ventilator fan mounted on the opposite end of the GH from the wet pad. But this means you can only use the wet pad for summer cooling (since you don't want to drag cold winter air through the GH in winter)

Since TN winters are dry, I mounted box fans on the front my pads, and built a louver system so that I can recirculate the air through the pads in the winter for humidification, but during the summer it brings in outside air for more efficient cooling. I get efficient humidification year round and decent cooling in the summer.

Rick, I wondering if a wet pad will be enough cooling for cool growers in the summer here as it can reach 95-100 outside without batting an eye?

I was thinking about using several box fans in front of the wet pad and pulling the hot air from the peak through the wet pad. Is this a good idea or should I just stick with an exhaust fan on the opposite end of the greenhouse?

 

[keithrs]

Actually, masdevallias take - and need - quite a bit of light. About cattleya level would be right. George Fuller, who spoke at our 2001 Mid-American, grows them in almost full sun in NZ upside down hanging out the bottoms of pots for better flower viewing. Is is a common misconception that since they are cool-growing they are shade-loving. Not so.

Your shade % is probably more about how well you can cool than too much light. I have gone to 30% aluminet here in Ohio (and would go with 20% if thought I could cool sufficiently), where admittedly we don't have quite as much sun as you do there in my idea of heaven.

I grow my most of my plant under a 55% shade house now and that tends to be too much for the Masd. and other "low" light plants and even higher light plants.... I believe that if I could get cooler temps I could go with more light.

Maybe I should split the green house in half and use 60% over the cooler growers and 40% over the higher light plants?

I'm wondering how well aluminet reflects the heat compared to normal shade cloth? This is the main reason why I'm thinking about Aluminet.