Building a Raised Bed Cover/Greenhouse from PVC on the Cheap

[Greg_Midi]

We're trying to grow things here in the Mojave Desert where Summers are brutally hot. We have a couple of raised beds; one I built from what used to be a gate and another that was ordered via Amazon. We've been at it for just a couple years here with some limited success and hope to improve our odds with a cover.

We're in a small NV town on the AZ border about 70 miles NE of Vegas. Very nice house we have but outdoor space is at a premium, the smallest back yard I've ever had. Although most landscaping here is rock there is an area in our backyard that had grass and sprinklers, likely for pets. This is the spot where we placed the raised beds and I've removed and capped off the sprinklers except two that are used for irrigation.

I've waited until cooler Fall temps to get started and the project is underway but there is much to do and I'll share the progress here for any who find it interesting.

As with any project it started as a concept, I wanted to keep it as simple and low cost as possible. After watching some youtube videos I came up with my own design.

I'm using 1" PVC pipe and fittings along with 1/2" PVC on lower sections under the auspices of stabilization. I'll leave it here as the first post.

 

[Greg_Midi]

I've hopefully bought all the materials I should need according to my drawing. In my list are also tools I bought for this project but will go in the toolbox for possible future use. I'm up to $223 but haven't yet figured out the actual covering yet, there appears to quite a variety and we may want to try different types at different times.

Where my design veers away from others I saw is my method for holding the thing to the ground. I'm using metal rebar type stakes and then will use silicon sealer to secure the PVC to the stakes if needed. Originally I had some smaller 16" stakes but those seemed a bit wimpy and I found some better ones at Vevor, 24" and 1/2" diameter.

 

[Greg_Midi]

So this type of project goes better when things are square and level. That was never considered when we put the raised beds there but fortunately they aren't terribly out of wack and it's not been too difficult to deal with.

I started out by squaring out the stakes around the beds. Originally all I had was string and a square but one restless night I got to wondering if there was a laser square I could buy. There was and cheap too, $14.00 was a no brainer!
Even then working on the uneven outside ground wasn't easy and I eventually figured out that it worked best sitting on a board that I could level up with cardboard shims and such.

With furthest ends done I used string to help place inside stakes.

 

[Greg_Midi]

With all the stakes placed and pounded 10" in I was ready to start cutting PVC.

I cut 4' pieces of 1/2" for outside corners and shorter ones in the middle.

I have a laser level and rigged up a mount on a camera tripod but it just seemed to be more trouble than it was worth getting the base level and going old school just seemed quicker and easier.

A 2x4, bricks, wood & cardboard shims seemed the easier way to get level for making height cuts.

 

[Greg_Midi]

About this time I got real busy doing some math figuring, the old adage, measure twice, cut once. PVC is real flexible but it makes sense to try and be as precise as possible. I calculated my lengths according to the original ground stakes and then added and subtracted according to measurements I took on the connectors.

I find it helpful to sit down and draw some things out, helps me visualize what I'm doing. A pencil with a working eraser really helped haha! The elbows and tees have an insertion depth of 7/8" but realistically 5/8" is about as deep as you'll go. The 3 & 4 ways have an insertion depth of 1 1/4" but again you're not likely to shove anything in deeper than 1 1/8" so all that has to factor in.

Also at this point, because there are so many pieces and I may need to disassemble for silicon, I really had to come up with a labeling method. I used direction (E for east, W for west), upper/lower, north/south, etc. and created another drawing with all my labels.

So at this point in time I've managed to get all my pieces cut for the lower section of my wood bed including a somewhat weird extension that goes back to line up with the longer length of the metal bed.
We're taking a short trip starting tomorrow so I'll leave it here for now.

 

[Greg_Midi]

We returned late Thursday night from a brief trip to Moab UT and I soon got back to work on this. I finished the pipe around the bottom of the shorter bed using the same techniques to keep it all level.

It became decision time as far as how tall I wanted my outside ends to be. I'd decided early on to set the middle height at 6'3" so I can get in and out of there without ducking down or bumping my head. I decided to go with 5'6" on the taller bed and 5' on the shorter bed.

I worried a bit about how I would level the upper ends front to back but then it occurred to me that because the lower sections are already level I can simply copy the front and back pieces, however, because of the difference in height between the two beds I did need to level across the front threshold. Having done that I shouldn't need the level anymore.

I began to worry a while back that I was going to run out of pipe and that's what happened about this time. Obviously my original estimates on how much I would need were awful far off hahah!

I suppose it's better needing to get more pipe than having extra I don't need but it also has forced me to take a closer look at what I need to do on the top. Because the raised beds are different lengths it complicated my design and so I went back to google drawings and came up with a new one to help me visualize the overhead view while helping determine how much more pipe I need.

I've got some calculating to do and then I'll make the trip up to Lowes in St George UT to get what I need.

 

[grayoldnproud]

We returned late Thursday night from a brief trip to Moab UT and I soon got back to work on this. I finished the pipe around the bottom of the shorter bed using the same techniques to keep it all level.

It became decision time as far as how tall I wanted my outside ends to be. I'd decided early on to set the middle height at 6'3" so I can get in and out of there without ducking down or bumping my head. I decided to go with 5'6" on the taller bed and 5' on the shorter bed.

I worried a bit about how I would level the upper ends front to back but then it occurred to me that because the lower sections are already level I can simply copy the front and back pieces, however, because of the difference in height between the two beds I did need to level across the front threshold. Having done that I shouldn't need the level anymore.
View attachment 2553498

I began to worry a while back that I was going to run out of pipe and that's what happened about this time. Obviously my original estimates on how much I would need were awful far off hahah!

View attachment 2553512

I suppose it's better needing to get more pipe than having extra I don't need but it also has forced me to take a closer look at what I need to do on the top. Because the raised beds are different lengths it complicated my design and so I went back to google drawings and came up with a new one to help me visualize the overhead view while helping determine how much more pipe I need.

View attachment 2553523

I've got some calculating to do and then I'll make the trip up to Lowes in St George UT to get what I need.

Should work fine since you shouldn't have any snow/freezing rain load to content with. That's what took ours down last year. 1" just wasn't thick walled(rigid) enough for the ice and snow we had (not much btw). We had to order the 4 ways online since no one had them.

I'm sure you've realized PVC isn't cheap.

Good luck I look forward to seeing how it comes out.

 

[Greg_Midi]

Should work fine since you shouldn't have any snow/freezing rain load to content with. That's what took ours down last year. 1" just wasn't thick walled(rigid) enough for the ice and snow we had (not much btw). We had to order the 4 ways online since no one had them.

I'm sure you've realized PVC isn't cheap.

Good luck I look forward to seeing how it comes out.

I'm pretty sure it should last quite a while around here, night temps do drop occasionally in the winter but it's a world away from all my years in IA where it gets frigid and stays that way.
Last year we had some tomatoes late into the year and they were looking great but suddenly one night it got cold enough to kill them. This might help with colder temps also.

I did some serious analysis, put some figures into Excel and got it figured that eight more pieces of the 10' 1" should get the project done. I ordered at Lowes for around $34 so it's hard to complain about that price.

Thanks for having a look, I'm like a dog with a bone getting after this project. When the structure is finished I look forward to really spiffing up the mess of an irrigation setup that's currently there.

 

[grayoldnproud]

I'm pretty sure it should last quite a while around here, night temps do drop occasionally in the winter but it's a world away from all my years in IA where it gets frigid and stays that way.
Last year we had some tomatoes late into the year and they were looking great but suddenly one night it got cold enough to kill them. This might help with colder temps also.

I did some serious analysis, put some figures into Excel and got it figured that eight more pieces of the 10' 1" should get the project done. I ordered at Lowes for around $34 so it's hard to complain about that price.

Thanks for having a look, I'm like a dog with a bone getting after this project. When the structure is finished I look forward to really spiffing up the mess of an irrigation setup that's currently there.

Have you gotten your plastic yet?

 

[grayoldnproud]

I'm pretty sure it should last quite a while around here

This might help with colder temps also.

I ordered at Lowes for around $34 so it's hard to complain about that price.

Thanks for having a look,

It should. The one we built was a lot larger hooped and we had braces up like you are doing but it wasn't enough. Which brings up the question, are you pitching the heights or hooping?, you need to have water shed or even dew will pool.

It should help some but it will still get cold in there, plastic sheeting is a sucky insulator. Add anything big and black that can retain heat, paint rocks, black buckets of water, trash cans of water. The larger the thermal mass the more time for them to release heat before equalizing.

We got ours at $19 and that sucked in my opinion. And that was at Home Depot just a couple years ago.

You bet.

 

[Greg_Midi]

It should. The one we built was a lot larger hooped and we had braces up like you are doing but it wasn't enough. Which brings up the question, are you pitching the heights or hooping?, you need to have water shed or even dew will pool.

It should help some but it will still get cold in there, plastic sheeting is a sucky insulator. Add anything big and black that can retain heat, paint rocks, black buckets of water, trash cans of water. The larger the thermal mass the more time for them to release heat before equalizing.

We got ours at $19 and that sucked in my opinion. And that was at Home Depot just a couple years ago.

You bet.

I'm totally winging it here, never built anything from PVC before. I'm not too concerned about rain or dew here but I imagine issues may pop up that I'd never thought to consider. This is all rather experimental and so time will tell and hopefully I can deal with any problems or issues that arise.

There won't be any hooping, the sides are angled and I can probably ad some pitch to the top section if needed.

 

[Ninjadogma]

I just loosely perused and didnt see what you're using to enclose it on the sides and up top, and hopefully you learned from my fail and factored in some sloping on the top so water doesn't pool anywhere.

 

[Greg_Midi]

I just loosely perused and didnt see what you're using to enclose it on the sides and up top, and hopefully you learned from my fail and factored in some sloping on the top so water doesn't pool anywhere.

The covering is yet to be determined, not sure what might be best or may want to change it based on the season, want to stay flexible on that for now so nothing permanent.

 

[Greg_Midi]

With a few estimates I used Excel to help calculate and split up the 10' pieces I still needed efficiently so I needed to number them. I'm still trying to base calculations from the ground stakes but I'm also getting a little more fast and loose with the tape measure. Busting out the trigonometry for the top angles would definitely be over and above.

 

[Greg_Midi]

Well this project is now finished as far as the structure is concerned I hope.

I figured it would sag a bit in the middle but I really didn't want to have vertical pieces in the middle of the beds. It seems sturdy enough for any of the lightweight covering material we'll use but I have left over pieces if I do feel the need to modify. I'm also going to hold off on using any silicone for now.

Next up will be redoing the irrigation there. I've already bought some parts to use and it will be real nice being able to zip tie the hoses on the lower pipes. I'll likely add misters in the top also.
I'll probably throw up a couple photos of all that later.

Not really an overly complicated project but I certainly did spend plenty of time figuring and planning. Glad to get to this point. Thanks for taking a look and I look forward to more serious growing adventures next year.

 

[Greg_Midi]

I spent a little time out here today. The last thing left in the metal raised bed was a jalapeño plant that surprised us by really producing. I plucked dozens of peppers off this little plant but it seems to have mostly run it's course now so I went ahead and pulled out the irrigation.

It had a Rainbird fitting that took the place of the popup sprinkler that had been there. In hindsight I now realize how unnecessary the extra expense of this fitting was after I discovered these extenders.

I used plenty of plumbers tape and put a cap on the extender and then used plenty more plumbers tape on the 1/2" fitting down in the ground.

The extender brings the line up above ground level, same as I've done to others nearby. Depending on whether I decide to use a filter I may tap into it for irrigation there again.

 

[Greg_Midi]

A quick update on this project. I've gotten the irrigation tubing into place and we can add the 1/4" tubing and sprinklers where we need them, my wife will have primary input on that.
Nearby I have bricks and 15 gal bags for the weed plants. I'll set up irrigation for those also but not needed yet. I'll plant those in March after we return from a road trip to TX and hand water for a while.

 

[cpurola]

Looks so clean and ready to be planted, great job!
(can you come over to my house and make mine look like yours? )

 

[Greg_Midi]

Looks so clean and ready to be planted, great job!
(can you come over to my house and make mine look like yours? )

It would be fun but I have to say, I wouldn't normally get up around your area until at least April!

 

[cpurola]

It would be fun but I have to say, I wouldn't normally get up around your area until at least April!

That's good, 'cause the way the winter's going, we may have snow in April. LOL