Author Topic: new greenhouse planning  (Read 42719 times)

SusanB

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Re: new greenhouse planning
« Reply #50 on: September 22, 2016, 09:11:01 AM »
Brian, how exciting!  I can tell you have put a tremendous amount of thought and work into it.  I really like the greenhouse you've chosen, when we bought ours the options were pretty limited, not many styles between small home gardener and professional. 

I'll have to go back and read through this thread more thoroughly. 

My plants are all in pots, although I've cut out the bottom of some pots to let them root through into the ground, after they took that route themselves, through the holes in the bottom of the pots.  The Ceiba and a few cactuses grow this way, some of the cactuses are at the edge of the greenhouse so I worried about them getting cold feet.  My guys did not do a good job on the base, it's basically a wooden wall with a little insulation tacked to it. 
I can feel that the bottom of the gh is cooler, but it hasn't seemed to affect anything so far.

brian

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Re: new greenhouse planning
« Reply #51 on: September 22, 2016, 11:15:02 AM »
Until next fall I am keeping all plants in containers.   Once I've seen how well I can maintain temps on the coldest and hottest days of the year then I will start planting in ground. 

I'm planning to take some temperature measurements in the center and edges of the greenhouse on cold days to see how low it gets.  The foundation will be 2ft down and insulated that far so I expect it should stay reasonably warm.  If it can't maintain at least 55F I will likely dig again and insulate further next year.

Looking at the excavation I can see that below a few inches of topsoil my yard is all heavy, heavy clay.  I think I will be amending compost or peat in. 

Mark in Texas

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Re: new greenhouse planning
« Reply #52 on: September 22, 2016, 02:05:43 PM »

Looking at the excavation I can see that below a few inches of topsoil my yard is all heavy, heavy clay.  I think I will be amending compost or peat in.

Never amend heavy clay backfill with anything when planting.  Here's the logic - https://puyallup.wsu.edu/wp-content/uploads/sites/403/2015/03/soil-amendments.pdf

brian

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Re: new greenhouse planning
« Reply #53 on: September 22, 2016, 02:49:31 PM »
I'm talking about doing the equivalent of a raised bed.

To be clear, the current state of the greenhouse interior is a slight slope of clay soil with grass lawn on top, covered with a huge mound of dirt from excavation.  I can either remove the dirt, level it out, or maintain the slope inside the greenhouse.  I'm thinking the irrigation water will tend to pool to one side if I maintain the slope, so it likely makes sense to level it out.  If I'm moving all this dirt around it would be feasable to add some organic matter evenly throughout.  For example, if there's 2ft deep of insulated soil in the 18x32 perimeter, thats 1152cu ft or 42.6cu yd.  So, if the clay soil is 1% organic matter, adding eight $10 3cf-packages of peat moss would push it above 5%. 
« Last Edit: September 22, 2016, 04:02:00 PM by brian »

Daintree

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Re: new greenhouse planning
« Reply #54 on: September 27, 2016, 10:47:45 AM »
Be sure and post pictures if you can - I love to see what folks are building and how work is progressing!!!

Carolyn

brian

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Re: new greenhouse planning
« Reply #55 on: September 27, 2016, 01:00:05 PM »
Right now I only have an exciting ditch!




I hired a local excavator to dig foundation and service trenches.  I'm starting on concrete forms this week.

Millet

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Re: new greenhouse planning
« Reply #56 on: September 27, 2016, 10:30:00 PM »
brian, when you sold your old house did the new buyer like the attic greenhouse? In other words was it an asset or a liability?  - Millet

brian

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Re: new greenhouse planning
« Reply #57 on: September 28, 2016, 12:32:38 PM »
My brother lives in my old house now, I haven't put it on the market. 

However, I am planning to revert the old greenhouse back to a normal roof/attic once the new one is vetted.  I'll ask a few real estate agents what they think but I expect the answer will be that it will be easier to sell without it. 

cory

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Re: new greenhouse planning
« Reply #58 on: September 28, 2016, 09:44:08 PM »
It would be interesting to know what the market thinks.  I would like a sunny room like that.  Maybe an artist might like it for a studio or someone would like it for a bright craft or workshop.  Maybe another gardener will like it.  I have been thinking of adding skylights to my garage roof.  Anyway, I don't think I would remove the "glass" roof until you test the market for it.  It is quite unique.
Cory

Tom

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Re: new greenhouse planning
« Reply #59 on: September 28, 2016, 09:52:33 PM »
I agree that I hope you can leave the improvement as is. Very unique and seemed very well done. I enjoyed reading about it a while back on the other forum. That data might be lost forever. I haven't been able to log on for weeks (or months). I'm glad Millet got this in place when he did !!

brian

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Re: new greenhouse planning
« Reply #60 on: September 29, 2016, 09:36:56 AM »
Did anybody make a backup of the old site?

Daintree

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Re: new greenhouse planning
« Reply #61 on: October 02, 2016, 07:00:33 PM »
Right now I only have an exciting ditch!
I hired a local excavator to dig foundation and service trenches.  I'm starting on concrete forms this week.

Actually that really IS exciting!  My greenhouse is much smaller (500 s.f), but I dug the ditch by hand, then filled it with gravel by hand, then me and my mom (in her 70's at the time), hauled all the cinder blocks for the foundation, using her little Toyota truck.

So yeh, that little excavator is WAAAY cool!!!

LaCasaVerde

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Re: new greenhouse planning
« Reply #62 on: October 22, 2016, 05:19:26 PM »
Loved reading this post so far.
side note:
I read earlier in the post about heating requirements/costs
Ive used this calculator for my heating needs and expense calculations for my greenhouse. May  come in handy:
http://www.littlegreenhouse.com/heat-calc.shtml

brian

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Re: new greenhouse planning
« Reply #63 on: October 22, 2016, 09:19:51 PM »
Yup, that's what I've been using LaCasaVerde.   I hope it is reasonably accurate.

Millet

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Re: new greenhouse planning
« Reply #64 on: October 22, 2016, 09:58:08 PM »
As I have mentioned before, I use 10 black plastic 55-gallon drums lined in a row as greenhouse benches.   The drums are filled with water which totals 551-lbs. of water per each drum.  The water heats up during the day, and cools at night.  It takes one BTU of heat to raise 1-pound of water one degree, or reversibly, when 1-pound of water loses one degree of heat it gives off 1-BTU of heat to the greenhouse.  The 10 barrels used to make a greenhouse bench, contain 5,510-lbs. of water.  Lets say when night comes the water in the barrels is at 66 degrees, over night the water has cooled down to 57 degrees.  That means the watered cooled by 9-degrees. Therefore, the total weight of water in the 10 barrels (5,510-lbs.) gave of 59,590 BTU's of FREE heat into the greenhouse.  I have one hundred 55-gal. drums in my greenhouse. Six benches, plus the sides and  ends are lined with barrels.  One added note, plants setting on top of the warm drums grow extra well through the long cold low  light winter season. - Millet

brian

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Re: new greenhouse planning
« Reply #65 on: October 23, 2016, 04:02:16 PM »
I'm thinking of doing water barrels also, though I have more limited space as my greenhouse isn't nearly as large.

brian

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Re: new greenhouse planning
« Reply #66 on: October 23, 2016, 09:37:10 PM »
Actually, because my greenhouse will essentially contain 2-4ft of insulated dirt, it might have a large heat holding capacity on its own.

Millet

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Re: new greenhouse planning
« Reply #67 on: October 24, 2016, 07:44:32 PM »
Brian the greenhouse dirt floor in my greenhouse is also insulated from the outside. My greenhouse is at 5,440-lb. elevation.  The air here in Colorado is thin, so it heats up quickly during the day, due to the strong sunlite raditation at this elevation.  However, it also rapidly cools after sunset.  At this time of year (late October), we have warm days 75+-, but night temperatures fall into the 30s, even one night at 25-F.   Therefore, I changed the setting on the greenhouse exhaust fans so that they don't come on until the greenhouse reaches 95-F, so the water barrels,greenhouse floor, and objects inside the greenhouse heats up, thus radiating more heat and for a longer time back into the greenhouse at night. - Millet
« Last Edit: October 24, 2016, 07:48:06 PM by Millet »

brian

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Re: new greenhouse planning
« Reply #68 on: October 24, 2016, 08:13:17 PM »
Perhaps the heat capacity of the soil isn't as much as I'd hoped.  I am planning to take soil temperature readings until I have a good feel for what to expect.  Do you have a concrete foundation?  I'm wondering if that will also hold a significant amount of heat.

Millet

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Re: new greenhouse planning
« Reply #69 on: October 28, 2016, 09:17:53 PM »

Millet

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Re: new greenhouse planning
« Reply #70 on: October 30, 2016, 09:54:39 PM »
How is the new greenhouse coming along? - Millet

Mark in Texas

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Re: new greenhouse planning
« Reply #71 on: October 31, 2016, 09:56:30 AM »
Beneifits Of A Retractaable Greenhouse Roof - Millet

http://www.freshplaza.us/article/6604/Video-Benefits-of-retractable-roof-structure

I looked for such a design on a small scale greenhouse with no luck before getting the Nexus Zephyr.

brian

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Re: new greenhouse planning
« Reply #72 on: October 31, 2016, 02:14:54 PM »
The foundation construction turned out to be far more complex than I anticipated.  I had spoken to some friends with concrete experience prior to starting but their experience was with pouring slabs which is much simpler than walls.  I had to spend a ton of time researching proper concrete form design to ensure they won't burst.  I'm getting close to being able to do the concrete pour.  The weather is still nice but winter is rapidly approaching.  If I don't get it done quick I'll have to resume in spring. 

In retrospect if I'd hired out the foundation it would only have been a bit more expensive than doing it myself.  It sure is a learning experience.  I have a handful of people to help me assemble the structure once the foundation is in place.  The greenhouse kit should be delivered in the next few days.  It took 6+ weeks to manufacture.

I put my trees in my old greenhouse for now, so the only urgency is that I hate having incomplete projects. 

brian

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Re: new greenhouse planning
« Reply #73 on: October 31, 2016, 02:19:02 PM »
From my calculations heating the greenhouse air should be reasonably affordable because natural gas is dirt cheap.  A lot of the efficiencies I though I'd need likely aren't actually cost effective with a fuel source this cheap.

I'm not sure about the ground temperature, though.  I won't really know until I get there. 

forumfool

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Re: new greenhouse planning
« Reply #74 on: December 26, 2016, 07:14:37 PM »
Bump.

Nice thread. Any update?