Opinions on Greenhouse set on concrete patio

[Diane]

Sooo - I'm seriously considering a greenhouse. (will be adding India and probably Brazil to my travel schedule next year) But I live in a community where the homes have large patios with only a 2 - 3 ft rim of 'dirt'. So a greenhouse would have to be set up on the patio. It seems possible to me that if I had a heavy wooden base, say 4"w by ?"h of lumber, that I filled in with pea gravel, that would work. The patio is already slightly sloped to allow drainage, I would have to put some sort of outlet in the base to make sure water did not get trapped. Then attach the greenhouse to the wooden base.

So, existing concrete slab, add a layer of heavy plastic over the concrete. Wooden base 4" thick by 6 - 8- 10 - ? inches tall. Fill in with pea gravel, make sure the base has appropriate draining holes. Could bolt the wooden base into the concrete as well to avoid wind problems. Figure out how to run a gas line in for the heater - I have an outside natural gas tap for a bar b q, so that part is done - wonder if I would have to run the line underground from the tap to the greenhouse? Same with electrical for fans, pump, timers... Hmmm

What do you all think? Any suggestions, comments, personal experience, is welcome.

[orchid-man]

the idea sounds good to me.I would think that a base made of 4x4 in sections bolted to the slab and then a solid 4x4 right around on top.That will give you a good base and the drainage.I would also make sure that the timber used was ground treated.

[Mark V]

First the mundane financial and regulatory considerations, Then the fun and interesting stuff.
In your sub-division is there an owners 'Mafia' association that doesn't want any changes or has approval authority over improvements?

If it is bolted to the ground (fixed to the ground in any way including utilities) it is probably considered a permanent structure and your insurance company wants to know about it, and the municipality is gkoing to have some building codes and permits you will have to submit to. Since you will have gas and electric service, it is probably a good thing to have inspections so some gypsy glass enclosure mechanic doesn't leave shoddy work behind him that blows up your back yard and incinerates your chid collection.

Because of the close proximity of your neighbors houses and patios you might check to see if you need a variance from the town before building.
Sorry about the downer quality of this post so far, but I live in a heavily regulated state, too. I have had my hopes for home improvements dashd by the minutiae of building codes.

What is the green house going to do the value of your property?
How long do you plan to live there? Would a green house kit that you can take apart and move with you a few years down the road be an option?
I recently looked into them for myself before I concluded I am not an active enough grower to deserve a green house, but I saw some very good looking ones on-line that took all the guess work out of the planning of a green house.
All that said, I will admit that back in the day (30 years ago) I completed an eight hour a day, year long horticulture course at the Norfolk Botanical Gardens. A large part of the course was on planning and building comercial green houses. Obviously the technology and prctical techniques have changed a lot since then, but it would be a gas to kibbitz on the brainstorming of your project.

[Brutal_Dreamer]

Hi Diane! I think, as you already know, it is a wonderful idea! I wonder if you should consider concrete blocks as the base instead of treated lumber? The blocks could be mortared in so that they are secure, but would allow the water to "get out" or "pass through" them (Unless you painted them with a waterproof paint - (I would not.)) I would do a minimum of two layers of blocks. Then atop of the blocks, secure a 2x4 (treated lumber) to attach the GH and the base together.

I would drop in the gas pipe and water pipe after the blocks were in place and before the GH was built. Once the pipes are in, insulate the water pipe where it could potentially freeze, run the base electric in conduit up to the top of the blocks in some location (probably a corner). Then have the base of the structure filled with gravel about the depth of one of the concrete blocks or 8" deep.

Then put your GH together and secure it to the 2x4 with 3/8" bolts about every 16 - 24 inches. Fill in the concrete block centers with pea gravel and seal the tops off with mortar on both the inside and outside.

Once the GH is in place, run the rest of your electric in conduit around the inside of the GH. Be sure to put plenty of outlets around the GH. Like a kitchen, there are never enough when you want to put in an extra fan or plug in a clip light to force blooming or something.

This is just an idea. If you decide to move and take the GH with you, un-bolt the GH from the base, and have the blocks removed from the patio. The big mess would be the gravel.

I do not know anything about codes, so someone like Mark V. may say that this is a bad idea. It would be my first thought. I would then run my idea by any construction friends who would be able to point me in the right direction.

I am so excited for you. Having a GH changes everything about growing these plants. I would hate not having one now that I have been lucky enough to build my own.

Cheers!
BD

[Diane]

bolting to the cement is the biggie when it comes to codes - if not, it is just a temporary structure and I don't have such a hassle. It will be a kit, I'm no engineer and I don't want to deal with construction people, AND I will want to take it with me as most people wouldn't want a greenhouse anyway.

[Mark V]

Codes differ in town to town. Though, every US town I've lived in, the inspectors wanted to check hard wiring or gas connections. It would just be a drag if you made a lot of plans and got your hopes up, to later find out it's not possible. Or worse: You started the construction and got a nasty-gram from the town. If just run a heavy duty extension cord (wink and a nod).....
I saw one series of kit greenhouses on-line that looked Victorian or Edwardian or something that, and they had me drooling.

[ABro]

Congrats on your decision to build yourself a GH Diane! I have a little input if I may... I know here in Florida you don't have to pull a permit if your job value is lower then 3000, and it is not attached to the house. Technically, your GH will not be attached to the house. It will be attached to the slab. There is a difference. If you do go with a kit I would just attach the bottom of the GH to the slab via tapcons. Of course put in a good liner to protect the slab from any mold/algea, or such. As for your electric and gas... I would have a professional install, that way if anything does go wrong someone can be held responsable. I would just check on codes, and stuff. If it turns out that you do need to pull a permit, you can always pull an owner/builder permit. An owner/builder permit allows the owner of the property to act as a contractor, and therefore higher their own subs or do the work themselves. Of course you will be required to complete any or all inspections required. I personally can't see you needing to pull a permit for the GH especially if it is a kit. But as far as the electric, and the gas I am almost positive that will require some type of permiting, and inspection. If you have any friends that you trust who do electric and/or gas then I would ask them to hook it up for you. Other then that I don't know! I wish you the best though in this venture

[ThirdDayOrchids]

Hello Diane
If You want to put in gas and elec you will need a permit to keep it legal in california.For gas anything over 3 feet long has to be inspected.The patio will have a natural grade or slope away from your house so drain in that direction.I agree with Aaron if you plan on moveing keep it simple attach with anchors to the slab they are easy to remove and repair.If you do it pm me and I will install the gas and elec leagel,all you have to do is put up with my 4 kids!I would like to bring the wife and kids they are a great help.seriously i have alot of experience in elec and gas it is a huge part of my job.I know cali code and will help with the inspector.Any help you need and all you have to do is deal with one contractor!!!
Jason

[Diane]

.If you do it pm me and I will install the gas and elec leagel,all you have to do is put up with my 4 kids!I would like to bring the wife and kids they are a great help.seriously i have alot of experience in elec and gas it is a huge part of my job.I know cali code and will help with the inspector.Any help you need and all you have to do is deal with one contractor!!!
Jason

OMG!! People on this forum are so awesome!!

I was beginning to dispair being able to handle it because I know nothing about building, and am gone so much that I would not be able to deal with a bunch of different people. What an amazingly generous offer! I will probably be in touch!

THANK YOU, THANK YOU!!!

[Piper]

She's happy. It's good - she's due give-back! Thanks, Jason!