How to Build a Simple Greenhouse Out Of PVC Pipe


Occasionally, when cultivating a stealthy marijuana crop a greenhouse is necessary for a few different reasons: first and foremost, your crop is less likely to get ripped off or busted if it can’t be seen. Second, some areas of our cannabis loving country have incredibly cold start temperatures in February and your tender young sprouts need to be protected from the elements.  Last but not least, the third most likely reason a cultivator might need to set up a quick and inexpensive greenhouse, is to try and create a light dep grow op as a means of potentially increasing their number of summertime harvests.

Construction materials needed:

All supplies easily purchased at Home Depot

All supplies easily purchased at Home Depot

For this chronic DIY project, the home cultivator will need some 1-1/4” PVC, a handful of 1-1/4” PVC T’s, a few four-way PVC fittings, about 20, 1-1/4” 45° elbows and some PVC glue; in addition to two, 12 foot lengths of 4” x 6” pressure-treated lumber and a handful of lag bolts to cinch it all together.  While the quantity of 1-1/4” PVC fixtures may vary based on the size of your greenhouse under construction, all of these items can be easily purchased at your nearest hardware store. For those with a power jigsaw handy, you’re in luck. You get to save a little elbow grease. The rest of you will need to use a hack saw for cutting the plastic PVC to its required lengths.

The below directions detail how to construct a PVC greenhouse that is 12 feet long and 8 feet wide:

Choose your greenhouse location wisely

Choose your greenhouse location wisely

Step 1). After first locating the best spot for your greenhouse – think Southern exposure –  the most important step, and one that will determine how easy your PVC greenhouse goes up, is determining how big you want to grow. With the average 4” x 6” pressure-treated post being pre-cut in 12 foot lengths at most lumber supply stores, two 12’ 4” x 6” pressure-treated posts will provide a 12 foot long greenhouse without any cutting required. As for the width of your new PVC pipe greenhouse, the sky’s the limit; with one small caveat. The narrower the greenhouse the more sturdy it will ultimately be – 8 feet wide would be just about perfect.

Making Your PVC Roof

Make sure to glue your joints

Make sure to glue your joints

Step 2). Take two 1-1/4” PVC T’s and one of the 4-way 1-1/4” joints and glue a 5” piece of PVC pipe – creating a short side on the 4-way joints. For the construction of this roof, there will be one four-way fitting located every 4 feet of the greenhouse length. Meaning that, 3 of these 4-way PVC joints will need to be prepared. Glue two 1-1/4” 45° PVC elbows at each end of the 5” segments of the PVC tubing.

Step 3). Allowing a few minutes for the glue to set, now take two equal lengths of PVC pipe and glue them into the 45° elbows. At the end of each equal length of PVC, now attach another 45° elbow.  This step is repeated in order to create the structural truss of your greenhouse.

Making your PVC walls

Step 4). Place your two 4” x 6” posts on flat ground. The post can be nailed to other foundation posts, dug into the ground for extra support, or they can be bolted to a cement footing provided one is available.

Step 5). As a means of providing greater sheer strength, holes can be drilled through the pressure-treated 4” x 6” post, now being utilized as the greenhouse floor’s sill plate. When done properly, the holes for the 1-1/4” PVC should be big enough for the tubing to fit snugly – but not too tightly. The use of a 1-5/8” drill bit should suffice for making the perfect size hole for your PVC.  For the sake of simplicity, drill the holes on a 2’, 3’, or 4’ center. This way the 12-foot sill plate will have either three, five, or seven evenly spaced holes in the pressure-treated wood.

Step 6). Measure twice, cut once. Make sure to cut the fat ends of the PVC off, then measure. Depending on where you purchase your plumbing supplies, PVC typically comes in 10 foot pieces – any longer is cumbersome and hard to transport. For the sake of keeping the math simple, let’s say we’re going to cut four pieces at approximately 4 feet in length. These pieces will be used in the construction of the walls. With the remaining side pipes connected to four-way 1-1/4” PVC T’s.

Step 7). Place the 4’ lengths of PVC in the holes of the 4 x 6 pressure-treated wood.

Step 8). Glue and connect each side to the other with the 1-1/4” PVC Ts.

Step 9). Through the 4” x 6” post and the 1-1/4” PVC pipe, drill a hole and screw in the lag bolt. To ensure a stable greenhouse, make sure the PVC is at the very bottom of each hole and be sure the drill bit is not oversized for your intended bolt.

Step 10). Now it’s just a matter of cut, glue, and cover. Glue the appropriate length pieces of PVC pipe to the top of each vertical four-way and PVC T.

Step 11). Secure each of your greenhouse trusses to the appropriate length pieces of PVC with glue. Then connect the four-way and PVC T’s at the top of the greenhouse with PVC pipe glue. (For those cultivators that live in wind prone locations, be sure to secure the greenhouse roof to the 4 x 6 pressure-treated foundation with some type of cable or turnbuckles, in order to avoid a repeat of the Wizard of Oz.

Step 12). Next up, cover and secure the greenhouse with some 4 mm visqueen plastic, and you’re off to the races.


About Author

Born in Long Beach, raised on the central coast: I surf, dab, burn, and blog – though not necessarily in that order. I'm a husband, a father and a lifelong consumer of connoisseur grade weed. I don't drink alcohol or consume any other "drugs." I consider myself to be living proof that weed is not a gateway drug. If it were, I'd be in some serious trouble. Instead, as a 50-year-old ex-realtor that has been smoking weed for nearly 80% of my life (just did the math) ... I can only say, marijuana is safer than prescription pills or alcohol could ever hope to be for calming what stirs the savage beast.