Last week I posted an article on how to build your very own greenhouse. Click here if you missed it.
However we never got to finish our project since I never shown you how to build the door. Today we’re going to do just that.
The design that I came up with is light, strong, simple, and can be built easily using only a circular saw and a hand drill.
This greenhouse door design can be built on a set of sawhorses out in the driveway, but it will be a lot easier if you get someone to help you hold things while you saw, drill and fasten parts together.
Needless to say you can seriously hurt yourself with power tools, and you should follow all applicable safety measures for the everything that you use. No kidding, a friend of mine lost an eye about a year ago because he wasn’t wearing safety glasses. Don’t make a mistake like that. Be Careful! Now let’s get to the materials.
– 1 x 2 stock -Link-
– 3″ screws -Link-
– galvanized utility wire – Link –
– wood glue -Link-
– scraps of plywood
– sheet of plastic (the size depends on your door size, you can use the same type as for the greenhouse)
– hinges -Link-
As I mentioned in the original article, the dimension of the door varies depending on how big you’re going to make the green house. For the door you’ll need to have 5 pieces of 1 x 2 stock: two pieces to make the sides, and three pieces to make the top, bottom and middle brace.
The sides need to be the same length as the finished height of your door while the top, bottom, and brace need to be 3 inches less than the width of the finished door.
Pre-drill holes before screwing the frame together. If you don’t pre-drill you will probably have problems with your wooden parts splitting when you drive the screws. Use a bit that’s just small enough to allow the screws to get a good bite. Try it on a scrap of wood first to make sure that you aren’t pre-drilling too loose or too tight.
I used 3″ washer headed self drilling screws, but any 3″ screw would work. If there’s a gap between the parts after you screw them together – back out the screw and re-drive it. There is no point in gluing these joints because glue doesn’t hold very well on end grain.
After you screw it all together, the frame should look something like this:
Now drill a hole in each corner to thread the brace wires through.
Thread a loop of wire diagonally both ways and secure the ends by twisting them together, and then twisting the tags back around the main wires. If you have some wire left over from the greenhouse use that. I used galvanized electric fence wire for this. You can also use small rope/large string, but wire is actually better because it isn’t as likely to stretch.
Clip the ends off and bend them neatly so that they won’t stick out and snag people, clothes, or greenhouse plastic.
Check your frame for square by measuring diagonally across the corners. If they aren’t about the same then tweak the frame a bit to get it pretty close to a square shape. Although this is a pretty forgiving design and unless it’s really out of square it probably won’t matter much – within a quarter of an inch is great.
Now use some scraps of wood to tension the wires. You want them to be merely tight, but not like guitar strings – just without any slack. This will pull all of the joints together so that they aren’t likely to come apart or sag. Check for square again to make sure you haven’t torqued everything out of whack.
And this is how the scrap wood should finish off.
Now glue triangles of plywood at each of the frame intersections – the corners, and at the cross brace. Notice the pencil marks to help keep the glue in bounds. Use a water proof glue like Titebond 3, and secure the connection with screws or nails. I used scraps of 1/2″ plywood for this, but anything from 1/4″ to 3/4″ sheet goods would work, or even solid wood, but lightness is a virtue so mind the weight.
You will be amazed at how strong and light this structure is. You can certainly use other sizes of lumber instead of 1×2 to make your doors – 1x3s would also work great for the sides, and 1×4 or 1x6s would be fine for the other parts. However, your door will be heavier (although it might be stronger), and you will probably have to recess the screws that hold it all together so that you get enough penetration for them to hold – or find some really long screws. You will of course have to adjust the measurements to work with your door size and the lumber that you use. Keep in mind that if your door is very heavy it might be more than your greenhouse frame can support without some beefing up.
Now we’re going to add the plastic. One thing to keep in mind is that condensation and rain will collect at the bottom of the plastic if it can, so don’t fold the plastic around the bottom of the door just staple it flush so that water can run out the bottom. On the sides and top leave a little extra to fold it around and double it up.
Now it’s time to add the hinges. I used a plain old loose pin interior door hinges. If you want to use the same hinges be sure and install them right side up though so that the pins don’t work loose and fall out. The main reason I used this kind of hinge is that it makes removing the door in the summer much easier. But you may use whatever hinge suits you better.
Next I added a cabinet knob I had around the house. You could also use a cabinet knob, or just a piece of 2×2 for a handle, or even a strap of leather from an old belt.
With that, the door is complete and you’re all set to attach it to your greenhouse.
Put a scrap of lumber under the door first to space it off of the ground. Now just set the door down on the spacer and screw it temporarily to the greenhouse in just the position that you want. Stand back and take a good look for obvious problems before you continue.
Now, hold a piece of lumber that will be the jamb right against the side of the door and mark about a quarter inch above the top of the door. Cut it off at this mark, and do the same thing on the other side. Then screw the two resultant side jambs securely to the greenhouse leaving about a quarter of an inch of space between the jambs and the door.
The 2x4s that I used for jambs are 1/4″ thicker than the actual door. This turned out to be a good combination because it left enough space between the door and the greenhouse for the door to open and close easily. The polytunnel plastic will assure a fairly good isolation. However, if encounter problems with gaps you can weather strip with scraps of foam carpet pad (or even carpet) and your staple gun.
Once you’ve attached the jambs you can screw the hinges to them, and remove the temporary screws that have been holding the door in place. At this point the door should open and close easily – if it binds or rubs excessively, back up and adjust before you go on. A common error would be to make the space between the door and the jambs too tight.
Now cut a piece of lumber to use as the head jamb. I ripped an angle on mine so that it would shed water better. I stapled the strip of black plastic to the back before attaching the head jamb.
The strip that was ripped off is then attached to the front to extend the jamb and give an overhang so that rain won’t run over the door. You could actually accomplish the same thing by just using a 2×4 that lays flat for the head jamb and letting it stick out.
Then, just staple and trim the plastic strip.
I added a simple turn bolt both inside and out, but you can do this however it best suits you. Be creative.
With that last touch the door is complete … but the greenhouse isn’t. You still need to make another one for the back. Follow the same steps and then you are truly done.
Now it’s time to grow whatever your heart desires. With the help of this greenhouse you’ll be able to eat healthy, clean vegetables and save a pretty penny on your grocery shopping.
How else would you build the door for the greenhouse? Share your thoughts in the comment section below.