Considering converting garage into a greenhouse. Need tips. - Orchid Board

Paul Mc · #1 10-26-2010, 08:06 AM

I am thinking about taking our garage and removing 1 side and the roof to create a greenhouse. It would not just be for my orchids as I have about 80 potted tropical plants excluding my 25 orchids. I must say though, if we do convert the garage to a greenhouse I will probably invest in many more orchids, lol...

I don't know that much about outdoor greenhouses, so I am wondering where a good place would be to learn about proper construction and considerations. For example, websites, books, buying a kit to see what they say.

I know some of the considerations woud be insulating the unremoved walls with siding, humidity, water source (as the garage does not have any water lines), temperature, air flow and ventilation

Any guidance to an appropriate research source would be greatly appreciated.

littlefrog · #2 10-26-2010, 10:27 AM

I have considered doing the same thing... Still not sure how to do it. I do know that my main concern is humidity rotting out the rafters. My structure has treated posts, but the rafters are regular pine since they were never intended to get wet. Thought about painting them with something, but still not sure what and how often I might have to repaint.

BikerDoc5968 · #3 10-26-2010, 10:32 AM

Quote:

Originally Posted by littlefrog

I have considered doing the same thing... Still not sure how to do it. I do know that my main concern is humidity rotting out the rafters. My structure has treated posts, but the rafters are regular pine since they were never intended to get wet. Thought about painting them with something, but still not sure what and how often I might have to repaint.

Rob, you just have to get a gigantic truck and move your exiting greenhouse to your new home!!!! And now that you've sold your other greenhouse you have all that extra cash to pay the freight!!!!!

BikerDoc5968 · #4 10-26-2010, 10:40 AM

Since you haven't given much info as to the location of your garage in relationship to other structures on your property or just how large a piece of property you have and where in the world you live, but "de-constructing" a portion of your garage to retrofit it for a greenhouse may be more work and more expensive than starting from scratch. As Rob stated untreated pine wouldn't be my 1st choice for support of a greenhouse. In my "other life" I built from scratch a 20' x 16' lean-to greenhouse. I used treated lumber, insulated glass and skylights for vents. It was a lot of work but worth every moment! So maybe more info about what your thoughts are could help direct comments from us.

dounoharm · #5 10-26-2010, 10:47 AM

i too would hesitate deconstructing a garage to make a greenhouse.....i would go the route of bikerdoc and build a leanto greenhouse or a freestanding one....it probably wouldnt cost any more and you would get a specialy designed structure....

BikerDoc5968 · #6 10-26-2010, 11:30 AM

In addition to having a greenhouse to your specifications, it's lots of fun, especially when you involve friends and family... then it really takes on some special meaning! And it really isn't as hard as you might think. Kinda like adult tinker toys or Lincoln logs!!!! Well, maybe a bit more work. Just remember measure twice, cut once! And make sure you are square... the 'ol diagonal rule.

Much of the materials are easily available at a big box store and for the glazing search online for UV polycarbonate panels, fans, heaters etc. But we can talk about the accessories and the "how to do" later in the plan.

ericst11 · #7 10-27-2010, 02:49 AM

I have seen this done where i use to live and one thing to do is find a place that replaces sliding doors because you'll need that nice double pane section of a sliding door to make the windows and it gives you that floor to ceiling window and insulated warmth then you need to look at whats weight bearing on that wall so you can frame those double panes into your wall you should put some sort of header above the windows to hold the weight of the area of studs you take out. Then for the roof the best thing to do would be to find out how many skylights you can put in on that section of roof to get the amout of light you want . Then inside i would use what they call green board and mud and tape that then go over the board with some sort of FRP board that you glue on and then you can get as wet as you'd like as long as its all caulked in . It sounds like a lot of work but really its not.

Brotherly Monkey · #8 10-27-2010, 03:48 AM

Quote:

Originally Posted by littlefrog

I have considered doing the same thing... Still not sure how to do it. I do know that my main concern is humidity rotting out the rafters. My structure has treated posts, but the rafters are regular pine since they were never intended to get wet. Thought about painting them with something, but still not sure what and how often I might have to repaint.

If it was me, I would either line the rafters with FRP, and seal with silicone, or paint them with an epoxy paint, like they use in plywood aquarium construction

Ray · #9 10-27-2010, 07:22 AM

Part of the problem would be that unless the roof is converted to being clear, you will be very limited in the amount of light that will get in.

Sealing the wood and adding artificial lighting might be a better option for a grow room.

Paul Mc · #10 10-27-2010, 08:30 AM

So many responses, where do I start? LOL... Thanks everyone.

To Bikerdoc, the structure is a one car garage with enough extra storage space to handle all of the outdoor shovels, tools, and many other things. It is not attached to the house and is in the only sun area of our backyard. That being said, the roof and only one side would be able to be removed for any light as the rest of the sides are on the alley, in shade, or against a privacy fence. I live in St. Louis, MO.

I did not think about having to seal the wood inside, that's a great tip!

As for buildling a greenhouse, we have very limited space and all of the sun area is taken up. St. Louis city yards are very small.

We had thought of just lining the rafters with grow lights and then proceeding with temperature and humidity devices, but we didn't know cost wise how that would play out in the long run. Would it be more cost effecient to do it that way and leave the garage structure alone?