Allrighty!
I've seen a fair amount of people having to work with doorless grow rooms, or grow rooms with inadequate doors, and questions arising on this topic. Both of the potential grow rooms I have chosen in the past have had this problem. After looking around I decided on making a Panda Plastic zipper door, and figured I'd write up a little how to to contribute what little I can to the site that has already taught me so much!
I know several people have used this method (or with velcro) but I couldn't find any write-up on it and I figure I might as well share my experience to others' benefit. So without further rambling...
Setting up a Panda Plastic Zipper Door
As you all know, finding a place to grow indoors isn't always easy, and often times there are hurdles one must jump in order to create a healthy environment for the room's future inhabitants. However one issue that is relatively easy and quick to fix is a lack of door or inadequate door.
Here's what I'm starting with:
This kind of door can barely pass during veg with a 24/0 light cycle, and of course there's simply no way this would fly in regards to lightproofing once 12/12 switch has been made. So, what I need is a fix for this, a door I can manipulate to my liking that will keep my room light-proof and leave room for ventilation.
Enter Panda Plastic. I chose this stuff because the black on one side white on the other design helps keep the lamp light in, and keep the outside light out. So far I love the stuff.. it's just thick enough but not so thick that it's awkward to manipulate.
What you need 
1 length of Panda Plastic: PP comes in either rolls or by the foot. Unless you have a large grow room you plan on lining completely I'd recommend doing it by the square foot, which runs a little over $1 per at the usual hydro/garden shop. I didn't bother to measure before hand and just picked up a generous amount so I would have extra to use as needed.
1 (or 2) zipper door(s): These are usually sold at the same shops that sell panda plastic, though you can order them online. They're relatively cheap and you can either use 1 to open the room with two flaps, or 2 and create a roll-up door. For mine I chose to use just one as I'm on a budget and the door didn't need to be large.
Ruler Sharpie/pencil/pen Exact-o knife or box cutter: You CAN use scissors, but an exact-o knife works soo much better for cutting straight lines.
Measuring tape Industrial Stapler: This thing was KEY in making my work 10 times easier. These staplers punch through wood, dry wall, or nearly any other reasonable surface with ease, and if you're working in a tight space (as I was) it's a handy tool, even if just to hold your PP in place before you seal it with another medium. Plus the holes it creates are tiny compared to push pins.
Duct Tape (optional): I used this for the ventilation but you could theoretically use it to hold down the PP/seal the edges.
Measuring out your door
First you need to measure your grow space door frame. If your grow space already has a useless door like mine, I would recommend measuring on the inside of the frame, leaving room for piping/air. Try to be pretty precise for the width, but for the length I was pretty generous as I'm using the extra length staple down/light seal the bottom.
My measurements came out to: 35 1/2 " wide, 86" long.
After writing down your measurements, return to your length of panda plastic. If you have a garage floor or hardwood floors it will make your life easier in regards to laying out this large piece of PP.
Take your tape measure and measure out the length and width on the panda plastic, marking them with your sharpie. As I said, I was generous with length so I used the crease closest to my length as my stopping point for length. For width, measure out your width every foot or so and make a mark on the panda plastic. This will allow you to use a ruler to make the cutting line straight.
Next, take the ruler and draw 2 straight lines for length and width following the marks your made. Once this is done you should have yoru door drawn out relatively neatly.
I say relatively because the panda plastic is difficult to smooth completely and you will most likely have minor variations. As you can see wrinkles, coupled with kitty interference resulted in a need for correction:
Make sure you double check the measurements as you go because of this.
Making the cut and attaching the zipper
If you did manage to get your hands on an exact-o knife, you'll want to use something like a cutting board under the plastic so you don't damage your floor and/or to provide a harder surface (if you're on carpet). Simply slice along the lines and experience the ease of the tiny keen blade.
Once you've cut out your door, flip it over to the black side and
wipe it clean with a damp towel. Dirt and dust will detract from the stickiness of the zipper door. Next you need to decide how you want your PP door to open.
To create the door, all you need to do is attach the zipper door, unzip it, and make a cut within it and voila! But first you need to position it.
There are essentially 2 ways you can stick this fella on here. You can either:
1. Position it at the very base of your door, so that when you open it it opens into two separate flaps
or
2. Position it a little further up, creating a large "hole".
The benefit of #2 is that with a length of PP at the bottom that does not come apart into two pieces, it is easier to seal the bottom down and completely lightproof it.
I chose to do a combination of both. I positioned my zipper a little up from the bottom, but made the cut within the zipper and past it, all the way to the bottom. This way, with a piece of duct tape covering the the cut I made past the zipper, I can more easily lightproof the bottom and feed/make minor adjustments on my plants, but with a quick removal of the piece of tape, the two sides will come away into flaps I can pull back when I need to do some serious work in the room. It really just comes down to what you need for your room.
Here's what mine looked like after the cut, the zipper beginning at the bottom:
Hanging the door
Now, none of this is difficult, but if there is any part that takes special care/time/energy it is hanging the door, and setting up ventilation and lightproofing. The latter 2 I'm only going to lightly touch on.
Now that you have your door, take it to your grow room to hang it. It helps if you have a friend. Step inside the growroom and get the door to a height that seems right, but also leaves some slack at the bottom for sealing. If you made a cut similar to mine, ideally you'll have the zipper end right at the floor, and some extra length trailing inside for you to staple/nail/tape/pin/velcro down.
Edit: After working with making the door air/light tight, the best solution to sealing the bottoms of the door would most likely be velcro, as you'll need at least one side's bottom to be able to be moved when you're getting in and out. Completely sealed top and sides + velcro bottom will do the trick.
This is where the industrial stapler became my best friend. Hold the door as taught as you can and staple down every few inches, both at the top and along the sides, and if decide you need it, the bottom as well.
As you can see the zipper hardly shows through at all.
Keeping the PP taught is a difficult task, especially if your cuts were a little off here and there, but just take special care and it will reduce the amount of light leaks you'll need to fill later on.
Once the door is hung, you're going to want to light proof it. Probably the easiest way of doing this would be to simply tape the sides, top, and bottom down. However, I will be lining the rest of my grow room with more panda plastic and will be overlapping the layers of PP to solve this. Thus I did not worry too much about tiny light leaks (my ladies are still vegging on 24/0).
Step outside, and your new door should look something like this!
Test your light proofing by stepping inside the grow room and turning off the lamp, making sure there are lights on/sunlight outside of the grow room. Fill in the light leaks using whatever medium you see fit.
Huzzah! A door!
Ventilation
Now, my ventilation is still in the process of being finished, as I will be adjusting the height of my light, shelf, and lining the walls with panda plastic before I go to flowering. However, obviously I needed to set up some sort of ventilation for the moment or my babies would cook.
So, first decide where you want your vent ducts to be. Arrange everything as you want it to be before hand (bending piping, setting fan positions, etc.), as even if you're like me and you're just setting up a temporary ventilation fix, whatever cuts you make in the panda plastic will be permanent.
**Let me take a moment to stress that my ventilation is a work in progress and most likely should not be replicated. HOWEVER, the cuts and sealing of panda plastic in the piping worked very well and I will share this portion at least with confidence.
For mine I used the standard bendable piping you can find at your average hardware store. I first bent my piping as I wanted it, positioned it inside the grow room and attached it to the wall/ceiling using a double bound loop of strong duct tape pinned into the wall. I am currently using one intake and one outtake. My piping is a bit long and may be cut down some in the near future.
If you're like me and still have that useless door in front of the panda plastic one, you'll most likely want to position the piping so that all of the bulk is INSIDE the grow room, resulting in 2 (or more) holes in your door, leading into the ventilation.
Once my piping was set up I returned to the outside of my grow room and, holding the piping firmly against the PP, made a cross cut on the plastic WITHIN the circumference of the pipe, then made 4 more cuts to make it into a star and release some of the pressure and prevent tearing the original 2 cross cuts further. Next, I folded these pieces of plastic back into the pipe, creating a nice seal. Out comes the duct tape, taping down these pieces inside the pipe, then reinforcing the inner taping with larger pieces. It ended up looking like this:
Here's what it looks like on the inside.. as I said it's still a work in progress so for the moment it's not too pretty.
This intake will most likely be cut down, and do note the cords were cleaned up right after the pictures
. It may not look like it, but both pipes are completely light proof sealed against the plastic.
I will also note that I moved my balast out of the room, and with that extra flap of plastic I left trailing at the bottom I was able to easily make a seal over the cords.
Well, there you have it! I hope this helped those people looking to solve their doorless grow room problems, or at least gives you ideas on how to go about your own personal set up.
I'll appreciate and comments and suggestions on how to improve! As I said, this is just one grow newbie's attempt at helping others learn from his experience.
