A permanent darkroom should ideally have a size of approximately 75 to 100 square feet or more. One side of the darkroom should be your sink or "wet" area. This is where you will do all of your processing, both for film and prints. The "wet" area should include adequate space to arrange your processing trays. The opposite side of the darkroom should be the "dry" area, where the enlarger and paper are located. It would be a mistake to align the wet and dry areas on adjoining walls where you might accidentally splash water or chemicals onto your enlarger, easel or paper.
See - Kodak Corporation's PDF Document "Darkroom Design for Amateur Photographers" - A free technical bulletin from Kodak.
Here in Canada, walls are constructed with 2x4 wooden or metal studs covered and finished with wall board (commonly known in North America as sheetrock, gyproc or drywall).
The walls of my darkroom are painted a cream color. I prefer light colored walls, however, if you do a lot of work requiring longer than average exposure times (example: 16x20 inch prints) or a lot of "burning in" or "dodging", then a darker, less reflective wall color in the vicinity of the enlarger might be a better choice. As long as your wall color isn't too bright and reflective, you should not have any trouble with unwanted reflected light. Painting your walls black is just ugly and unnecessary.
I have wired my darkroom with 7 electrical outlets in locations that are convenient for use, 3 of which are 6 feet off of the floor to provide a power source for the safe lights. Positioning the outlets at this height allows you to mount the safe lights right beside the outlets and avoids dangling electrical cords. I installed one 3 foot long, 240 volt baseboard electric heater with a wall thermostat, which provides more than adequate heat for a room of this size. Ventilation is provided with a fairly powerful exhaust fan in the ceiling, which has been wired to a variable speed control, mounted on a adjoining wall.
Room lighting is various for different needs - the main room light is provided by two 4 foot
fluorescent tubes on the ceiling in the center of the room. I have one safelight a few feet
from my enlarger and two more over my sink area. I have three ceiling lights
all with 7 watt bulbs, each controlled from its own wall mounted dimmer
switch. I have one of these lights over my enlarger area, one over a large
dry work area and one over the sink area. The 7 watt fixtures allow me to turn on a
dim source of light after working in the dark, so that I may examine a negative or find a tool that I need.
I can then turn off the light again and my eyes will adjust much quicker to the darkness, than if I had
turned on the main room lights.
Your darkroom door should emulate the construction of an exterior home door. A cheap hollow core door is fine, but you need a threshold, complete with weather stripping. The weather stripping will allow you to make a light tight seal with relative ease. You will also need to caulk any gaps between the door jamb and the wall framing, using a black or dark brown caulk. Make sure that you also caulk under the threshold. Once the caulking is in place and everything is light tight, install a proper door casing (trim) around the door. Equip the door with a locking door knob or something similar - you don't want someone opening the door and letting in light while you have an $80.00 box of paper open.
Temporarily Light Proofing A Window Or Door
This is a great idea submitted by "Doni" and could be used on a bathroom window or even a door - "I had a problem with light coming in a window. I tried everything from foil (took for ever to put up and looked bad) to shades and blankets. I wanted something that I could easily put up and take down. I finally found the solution and it only cost $16.00 and a couple of hours to make. I went to the fabric store and purchased room darking back lining and a nice top fabric and some velcro. I have sewn the two fabrics together and on the inside have sewn one part of the velcro. The other part of the velcro had self adhesive sticky backs to it, which I stuck to the wall just past the window trim. It works perfectly, it's a snap to put up. It looks good when it's up or down".
I thought of another method - One inexpensive material, might be the insulating blankets that are made for the purpose of wrapping around home water heaters to retain the water temperature. They are thin - I think about an inch maximum and have an aluminum foil coating on at least one side. They can be easily cut with scissors and joined together with duct tape.
Leave the covering larger than the opening that you want to cover. They could probably be tapped in place temporarily using less agressive tape than the duct tape.
The covering could be easily rolled up and stored when not in use.
The dry side of the room has built in counters with shelving below. You need a generous working counter - nice to have an area where you can space everything out for loading film into processing tanks before you turn the lights out - remember you need total darkness for film loading. If you drop something while in total darkness you won't have to worry about banging your head if you have allowed adequate space during the room planning stage.
My original sink was a disappointment. Home built, L-shaped and large, it measured 9 feet by 5 1/2 feet by 9 inches deep and 2 feet wide. It was based on a 2x4 frame covered in plywood and then covered with black plexiglass sheets 1/8 inch thick. It was and is a nice dimension to work with. The plexiglass sheets were cut down on a table saw from their original 4 feet by 8 feet sheets and joined together on the plywood with silicone caulking. Because of this design the drains were a major problem - difficult to slope the sink so that water would not sit in the corners, and also difficult to mount the stainless steel drains because of the flat sink bottom. The stainless steel drains are far from ideal as they corrode readily when exposed to darkroom chemicals. I would recommend the use of plastic drains, if possible.
I have now redone the wet side of the room. I have replaced the large sink with two plastic laundry sinks. I use one of these sinks for mixing chemicals and cleanup. The other sink is a print washing station. I have constructed a ceramic tile counter between the two sinks, that is long enough to accommodate my largest trays.
I purchased a pair of shut-off taps and joined them with a copper T-fitting. I then formed the center supply tube from 1/2 inch copper tubing 20 inches long. I placed a flexible spring tubing bender over the copper and formed a nice gradual bend. What I was aiming for here was a similar look to the faucets in the North American High School Science rooms. I ordered the tapered chrome ends for the faucets and installed them onto the short end of my bent pipe. The other end of the formed pipe was soldered into the T-fitting. To complete the job, I cleaned the copper with steel wool and sprayed the whole assembly with a clear lacquer. This keeps the copper nice and shiny, preventing the copper tubing from oxidizing and turning green as it ages. Its still looks great after 15 years of service. Note - for the tapered ends of the faucets, slide onto the tapered end an appropriate diameter of clear plastic tubing that is long enough to reach just above the bottom of the sink. This will prevent water from splashing everywhere when you turn on the water.
- See Ventilation Page
DO NOT use carpet on your darkroom floor