So I've been thinking of building a greenhouse from a kit but I just realized that on our property we have two car ports that are unused. They are roughly 16x20 so if I joined them I could have a structure that is 16x40. The posts appear to be roughly 4'8'' from each other.

So what materials would you recommend for the walls, I would want them to be pretty insulted (tropical plants ideally) but because of the shape of the carport structure parts of the walls will probably need to be somewhat flexible or I'll need some corner pieces to join them together.

I'll see if I can get some pictures next time I'm there.

Thanks.

@mntgoat I would think choosing the wall materials would depend on your climate.

Oh sorry, yeah that makes sense. I'm in KS, zone 6b.

may not work for you ...

saw a greenhouse once made from repurposed cinder blocks .... wood window frames and wood siding in 4" or 5" wide

cinder blocks formed the lower wall, back and door frame opening ...

old window frames with glass rested on the cinder block wall .... wood siding secured the window frames to block wall

it had an "A" frame pitched steel roof with water collection gutters ....and repurposed skylights for vents

very sturdy ....and it looked like it had been there a hundred years

We have a 2-car garage here, zone 5, with brick veneer over 2x6 insulated sheetrock walls, insulated, sheet-rocked ceiling, 1 2-1/2' by 4' window, metal garage doors, on concrete floor. Without a heat source it gets into the mid-to-low 30° range during winter. I grow all my garden vegetables in the basement, from seed.

We made our back porch and greenhouse from old windows, in frames, reclaimed from demolished buildings. They both leak.
The problem with recycled building material is fitting them together and sealing the joins. Very tricky; not in everyone's skill-set.
There are some good videos on You Tube, and books you can consult, to find the best match for your location, orientation, budget, capability and best use of the existing structure you want to repurpose.

Go for it!

No structure is going to hold heat without a heat source. The insulation of the walls and ceiling will determine how much heat you will need to add.

Without photos, its all in my imagination. I'm imagining a carport like Grandma used to have: Aluminum roof with those little scrolly legs holding the front up (the back is attached to the house). But that's not right. I think you could stick build the walls and corners and add Polycarbonate panels.

First, my apologies for the lack of replies, I never get notified that I have replies here despite me having this thread as watched, I must be missing some notification setting.

I forgot to take pictures today but did find an old picture of the side of one of the carports, they are both almost identical.


I do plan on having a heat source but that hasn't been decided yet.

I guess my question is, what is my best option on those polycarbonate panels? particularly considering the corner where it goes from wall to ceiling, since it isn't a straight corner.

Thanks.

@mntgoat you might need to "customize your home page" to show you the updated watched threads and forums (at the very bottom of your home page there is a "customize" prompt).

Someone else may very well have better advice, but if you want to use the polycarb panels I would be inclined to attach some wood framing (1x2s maybe?) such that the walls and roof come to an actual angle. Or you might consider using greenhouse film, which would conform to the curves. (Or possibly the panels will bend to accommodate the curve of the roof - ?) Fortunately we have plenty of knowledgeable GH builders here!

Mntgoat, a year ago I got some 10mil on Amazon and I'm pretty impressed with it as it holds
the heat well. Scream and I can sent the infro. or photos of our Brug House.

karmahappytoes said:Mntgoat, a year ago I got some 10mil on Amazon and I'm pretty impressed with it as it holds
the heat well. Scream and I can sent the infro. or photos of our Brug House.

Zone 6 Kansas VS Zone 8 PNW... How will the film do in temperatures at least 20 degrees colder?

Daisyl, the first year we had 19 inches of snow and very cold weather. Then this summer we had a week of
over 100 degrees and this happened a couple weeks later. The plastic is just like it was when I put it up. If
I had the 6mil it would of been cracking and shredding. Climate change is causing issues all over the
globe. With that stated, we are about to drop to freezing in the next 24 hours. Heads up Winter is coming
early and it's going to be a bad one!!

In zone 6, it warms up to snow. My comment had to do with the insulating value of 10 mil when its too cold too snow, not how well it lasts. I moved from zone 8 to zone 6 - the difference 2 zones can make is beyond amazing.

Yeah that would be my concern as well, how much insulation would 10 mil provide. Maybe if I do two layers? One around the metal on the outside and then one around the metal on the inside?

Mntgoat, I just run a small heater on out 10X20 Brug House but this year I'm going
to put a back up one on the other end. Beings that I'm from the NE area I sure would
run two. The 10 mil is much heavier than the 6mil that some folks put up and we only
remove the top in the summer month but your carport is metal and would also help
keep the heat in once it's warm. The company had many sizes to select from and
you would also need light due to the metal top. Have you given any thought to what
you would do for a door?

Weedwhacker said:@mntgoat you might need to "customize your home page" to show you the updated watched threads and forums (at the very bottom of your home page there is a "customize" prompt).

Is there no way to get this site to email me when there is a reply?

karmahappytoes said:Mntgoat, I just run a small heater on out 10X20 Brug House but this year I'm going
to put a back up one on the other end. Beings that I'm from the NE area I sure would
run two. The 10 mil is much heavier than the 6mil that some folks put up and we only
remove the top in the summer month but your carport is metal and would also help
keep the heat in once it's warm. The company had many sizes to select from and
you would also need light due to the metal top. Have you given any thought to what
you would do for a door?

No idea what could do on the door or back side. Maybe I can make a wood frame on both ends that would allow for ventilation on the summer?

Do you have a link to the 10 mil you got?

Also I see some 10 mil listed as 4 year, does that mean it is only meant to last 4 years? For example https://farmplasticsupply.com/...

https://www.amazon.com/s?k=10+...

Expose is the brand we got, but there is a lot to select from.
There is a lot one can do with the carport you have if one is crafty!

New question: What's holding the carport to the ground? You are about to make a giant sail.

mntgoat said:

Is there no way to get this site to email me when there is a reply?

I believe you can only get email notification for private messages.

With the greenhouse film, they "guarantee" it to last for 4 years, but I think a lot depends on your climate; for example, the UV exposure that my GH receives is a lot less than one further south.

After reading Karma's post, I'm curious about the metal top on your carport - are you planning to leave it on? (I was assuming that you were going to remove it)