Workshop bathroom that can do double-duty as a darkroom

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So there's no guarantee that I'll do this, but figured I'd look into it before making decisions that specifically rule-out the possibility.

I have a detached 24'8" by 38'8" workshop that was built with the house that includes plumbing in the ground for a bathroom in one corner. At the moment the only thing installed is an old plastic shop sink. Since I'm strongly leaning towards installing at least a half-bath, if not a 3/4 (shower, commode, sink) and I'm also thinking about leaving room for laundry (admittedly on the fence about that) I wanted to find out what kind of space and layout would be needed to be able to use this space as an occasional darkroom as well.

I'm attempting to keep this room as compact as possible. Prior to the idea of a darkroom I'm leaning towards 8' by 5', partly based on what I know of what's in the ground for that plumbing.

My prior experience in a darkroom was 20+ years ago in high school, and of course that darkroom was sized for three or four students to use simultaneously. I assume that short of any hypothetical enlarging equipment, this darkroom would be considerably smaller. How small can I reasonably go and not hate hat I've created?

For what it's worth I'm not in a hurry.
 
From the standpoint of working comfort IMO standard kitchen base cabinets would be best. The cabinet itself is 24" deep. Standard countertops are 25" deep. Standard base units come in widths of 9" up to 36" wide, so it wouldn't be hard to match up with either direction. Layout depends partly on where you put your door and will it swing in or out? If you put your counter all the way down the 8' length, which wouldn't be overkill if you have a sink also, it will only leave you a 35" wide isle, which is tight. A 30" door with trim requires roughly 37" of wall space so you'd either have to stop short on your base cabinets, notch/cut the trim, or go with a smaller door (which isn't a good option) if you put the cabinets along the short width, the door would'nt be an issue but your counter space would suffer. Ideally increasing your overall dimension to 6x8 minimum would allow you to utilize an 8 ft wall, and put the door in the end. You could use the 5x8 but the door would need to swing out and be in the 8ft wall. This doesn't include space for a commode either.

That's not to be said you couldn't use a 5x8. If you go with standard bathroom cabinets they're roughly 20-21" deep. You'd gain just enough that you could swing a 28" door in end, get roughly 6' of counter space (minus sink) and still have room for a commode. You'd also lose about 6" in height.
 
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Door is most likely going to be on the narrow end.

This is an exerpt from a drawing I'd done for the workshop back in 2015:

workshop-bathroom-area.jpg

Shop Layout Lift-Concrete-3-simplified_1.jpg

Basically there's an area 8' by 24'8" on the end where the floor is 4" higher than the rest of the workshop. Since I'm going to have to have some sawcutting and repouring for other purposes anyway, this gives me the opportunity to prepare for the bathroom by leaving the concrete at its location up that 4", while re-pouring the rest of the raised area flush with the main floor. In the process I might as well make effort to keep the bathroom design flexible, insofar as the smallest bathroom I can design that suits purposes such that it doesn't take up too much shop space.

The vent pipe is probably not realistically moved. The capped toilet drain is right in front of the vent pipe and the shower floor drain is to the left close to the upper left corner.

I'm also considering putting a shop sink outside of the bathroom somewhere on the 8' wall, depending on what I do for a door.

"Sink Area" is where the current utility sink sits. I do not necessarily plan to retain that fixture as it is now.
 
I always found it easier to add a bit to what think I need then try to figure out how to make it work after the fact. :cool-48:
 
How deep, wall to the front edge of the counter, do you find that you actually need?

I ask because I'd probably be building the cabinets myself, and wet-bar counters are often smaller than kitchen counters. It would be relatively easy to go that kind of route instead, to keep the sizes down.
 
How deep, wall to the front edge of the counter, do you find that you actually need?

I had always used 42" as a working width. Current OSHA is 48". If you go with a 28" door and put toward the corner on the 5' wall you'll still need to allow at least 37" for framing and trim. So 42" in a residential isn't far off.
 
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How deep, wall to the front edge of the counter, do you find that you actually need?

I had always used 42" as a working width. Current OSHA is 48". If you go with a 28" door and put toward the corner on the 5' wall you'll still need to allow at least 37" for framing and trim. So 42" in a residential isn't far off.
I meant in the horizontal plane, from the back wall of the counter at the backsplash to the lip of the counter right in front of one's self.
 
How deep, wall to the front edge of the counter, do you find that you actually need?

I had always used 42" as a working width. Current OSHA is 48". If you go with a 28" door and put toward the corner on the 5' wall you'll still need to allow at least 37" for framing and trim. So 42" in a residential isn't far off.
I meant in the horizontal plane, from the back wall of the counter at the backsplash to the lip of the counter right in front of one's self.

Standard kitchen counter top is 25". Bathroom counters are 21-24" depending on the base cabinet used. If you build your own custom cabinets it's not that hard to build a cutom top to match.

I guess the other thing to consider is just how much you plan on doing in the dark room. If you're just developing film, your counter space requirements would be less then if you had an enlarger and trays for prints.
 
Other things to think about
You will want to build a light tight vent and fix an extraction fan
As consider v carefully what else you use the room for
Dust and fibres from washing tumble drying will ruin your chances for getting good prints
Wet negs just love to attract dust fluff when they are hanging to dry so does photo papers
Add to that the things you have to think about with the camera, the enlarger is the same
A hair on a neg looks like a tree trunk on an a3 print
You may want to look into waste disposal regs where you are re dumping used chess
 
@Original katomi brought up some good comments. Venting a small room like that is pretty important considering the chemicals. Hanging film up to dry may not be an option. I've seen several designs for film dryers made from PVC pipe and light bulb or small fan, but I found this one, that's nice because it collapses. Do It YourselfBuild A Low Cost Film Drying Cabinet
 
As consider v carefully what else you use the room for

You really don't want to think about what the primary use of that room will be for... *grin*

In all seriousness it sounds like perhaps I should refrain. The shop itself is used for woodworking, auto repair, and metalworking including welding. The room will get an adequate bathroom vent-fan, but it won't be anywhere close to hermetically sealed. Cleanliness would be a problem even before considering other uses of the room itself. I suppose that was part why I was asking how much counter would be useful, since setting up the room to do occasional darkroom stuff might be handy, but in the end the environment might be too harsh to get good results.
 
Cleanliness would be a problem even before considering other uses of the room itself. I suppose that was part why I was asking how much counter would be useful, since setting up the room to do occasional darkroom stuff might be handy, but in the end the environment might be too harsh to get good results.

I won't say its' impossible, but you're adding another layer of difficulty. My shop has a dust collection system and an air cleaner/filter, yet still leaves a little bit of fine dust in the air, depending on the operation. Rather then venting (exhausting), I'd probably use a pressurized venting that would draw clean air in from inside and keep any dust from in the shop from being drawn in. Still if you're only occasionally developing a roll of film, you don't even need a darkroom, load your film in a bag.
 
Get off the fence, forget the laundry! Have you no priorities??! lol

I used to use a local college darkroom available to the public. Even there with a drying cabinet, etc. as Katomi said - dust... I always had to wipe off the enlarger lens to avoid getting dust marks on my prints.

That darkroom had great ventilation. You don't want to walk into even a darkroom with it running all the time where chemistry has been left sitting out... whew!! College students are slobs, especially if it's getting close to the end of the semester or nearing spring break. (That developer was coal black, I don't know how they were getting any prints out of it.)

Anyway, ventilation and enough counter/sink space for 3 standard size trays, and sink for the rinse. A drain in case of spillage? I would! lol And if you plan to print, maybe a drying rack... I'd thought about screens used for silk screening, maybe stack them (I've done lumen prints which use vintage paper that's small, little trays, and only need diluted fixer and water which I can do in my kitchen sink). After using my own Kodak big black rubber squeegee I used to use a print drying book so I could carry prints home not fully dry and lay them out on the kitchen table.

If it gets close in there I'd only do so much at a time, then open a door, turn on the light, etc. Once you have prints in the fixer or the rinse, you can get out of the dark. But I'm a darkroom rat, I like it in there. Our high school darkroom was only big enough for a couple of people I think, I wasn't doing photography yet then, I was in the school newspaper staff room editing the paper and breathing rubber cement fumes. So if in a small darkroom I'd probably break up the time in there at a stretch.
 
Our high school darkroom was only big enough for a couple of people I think,

Definitely would've wanted to make sure you were in there "in the dark" with people you liked. LOL When I owned the newspapers, I had a nice darkroom custom built, that could handle film, prints, and the 20x24 graphics arts films of the newspaper pages. It was well laid out for production processing, everything had a place. We took turns in the dark.
 
I would do as @smoke665 suggested.
A filtered fan to blow air INTO the darkroom to pressurize it.
I would intake the air from the outside, so you are not fighting the shop dust. IOW, the air source should be from the cleanest source.

Although if you go into the bathroom from working on a wood project you will be taking wood dust into the darkroom with you. And as you move/shake your clothes, the wood dust will be entering the darkroom air. A "dust-off" procedure outside the darkroom door would be a good idea, to reduce this dust contamination.

I would think about some kind of door between the laundry and your darkroom, to reduce the lint dust.
Keeping an air filter running in the laundry will help to keep down the airborne dust level.

You will also need/want a chemical vapor exhaust fan near the site that you will have your chemical trays and where you process film.
Though there are now low odor chemicals, so the smell isn't as bad as it was in my day.

re film drying:
My issue with the garment bag is they are not tall enough for a full 36 exposure roll, without cutting.
I had this hassle in my own darkroom at my parents house. There was never a good solution. I ended up cutting the roll into 12 exposure sections, and hanging the cut sections individually.
You could make a small film drying cabinet, about a foot square and about 7 feet tall. Put a 40w bulb for heat, and a filtered fan if you want. My local community college uses an unheated empty cabinet, just for dust control. The film dries overnight.

re counter height:
Tip. for the counter, make the height of the counter + tray to match your elbow height while standing on a floor cushion.
Bending over for long periods of time is hard on the back, especially as you get older.
If you make a large sink, this should be the height of the edge of the sink.
Of course, this means it fits YOU, not anyone else.

re counter depth:
How BIG a print do you plan to make? That drives the counter depth.
A 16x20 tray requires a 23+ inch depth, an 11x14 tray requires a 17+ inch depth. The tray size drives the counter depth.
tip: As big as you think you will print, go up one size. I did 11x14, but sometimes thought about 16x20.

re: counter size:
Like the depth, the length of the counter depends on the max print size, and the size of the chemical trays.
You want space for at least four trays: developer, stop, fix, hypo clear/pre-wash bath.

re print washer
Also related to print size is the need for a print washer of that size.
BIG print washers are expensive.
You have to plan for the plumbing for the washer. You CANNOT lift a washer full of water, they are HEAVY.

re: print drying
You need a relatively dust free place to dry the prints.
You don't want dryer lint on your prints.

Tip, paint color:
Paint the darkroom walls and ceiling WHITE, with FLAT BLACK around the enlarger to reduce enlarger fog.
My high school darkroom was BLACK, and it was a difficult place to work in, if you were not right next to a safelight.
When I visited another school, I was SHOCKED. The white and light green darkroom was so much easier and pleasant to work in.
So when I made my own darkroom, it was white; walls, floor and counter top. Two small safelights illuminated the entire darkroom, and there wasn't a dark corner. :)
 

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