Building a dedicated darkroom

Ok, I'm a little surprised that there isn't a dedicated sub forum for darkroom design, just about any equipment you could ever want but nothing for the room it gets used in.

Anyhow, after years of blocking the light from our bathroom to enlarge a few negatives then taking it all down again so we have our bathroom back I have decided it's time to build a dedicated darkroom. Unfortunately we have no spare rooms in our house and I feel a little gutted that we don't have a basement so onto the next available area... the garden.

In the garden we currently have an 8x10' greenhouse that is looking a bit of a sorry state, we also have an 8x16' shed that's falling over , after a quick chat with our landlord we have been given the go-ahead to carefully dismantle the shed and the greenhouse and re-build in a more usable way.

The basis of my plan is to build an 8x10' brick foundation on top of the 8x16' concrete slab to allow for raised wooden floorboards and to add a little extra height to the greenhouse walls (yes, I'm making a darkroom out of a greenhouse, maybe not the most logical starting point!). The greenhouse frame will be re-built on top of the brick foundations and lined with the tongue and groove board from the shed, the roof will be lined with the OSB roof boards and felted, the door will also be lined with tongue and groove board. After the electrics and water have been added in I will be lining the entire inside of the room with polystyrene board for extra warmth in the winter. Conveniently my mum is having a new kitchen fitted next year so I will be acquiring some kitchen units, sink etc... to kit out the darkroom.

I will then be building a smaller shed on the remaining 8x6' space left on the concrete slab for the garden tools.

Hopefully this build will start to take place in a couple of months (weather permitting) and I will use this thread as a kind of build diary with lots of photos of the work and (hopefully) a nicely finished darkroom.

First of all I need to clear out the shed, having a large shed doesn't mean things get spread out more, it just means you hoard loads of rubbish!

Keep an eye out for updates (might be a little quiet for the next couple of months while I wait for the weather to warm up) but it will come!

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I'm liking the darkroom portrait thread, lots of ideas and examples on there.

shed darkrooms are fantastic. i got a used 6x8 ft shed on the cheap, insulated it, paneled the walls and built some inner doors. totally lightproof and totally brilliant. i run an extension cable through the kitchen window for electric and use the kitchen sink for print washing etc. see here: http://www.twelvesmallsquares.blogspot.co.uk/2013/05/for-i-am-man.html http://www.twelvesmallsquares.blogspot.co.uk/2013/10/improving-shed-darkrom.html

Thank you for that, I've bookmarked it as it's an interesting guide to follow on tea breaks while the build is going on. The shed that's in place already has electrics in it with sockets and lighting so a few modifications to add in the red lights and another few sockets (plus getting the father in law to change the RCD to a 40amp, luckily the cabling is already 40amp). We also have a drain not far from the shed a short trip along the fence, and for the water inlet I will add a hoselock fitting to the sink so I can just plug the hose in (cold water only unfortunately).

This one is being built on a virtually non existent budget so it will be fun.

I'm hoping that the greenhouse door will be simple to lightproof as it has a sliding door, that and I will use a huge light proof curtain across the inside of that wall too for added protection.

Jim

Assuming water and power are not issues, (Part P - What's that? ) the next biggest priority for you is going to be insulation! What I suggest is that you consider the frame and T&G as just weatherproofing and then build an insulated box inside it. This includes roof and floors. Not difficult - build a wooden frame out of 2x3 stud. On the outside of the internal frame staple a damp-proof membrane so there is an air gap between the membrane and your external wall. Fill the gap between the studs with polystyrene, or better still rockwool and line with plasterboard/ply or whatever. Your wall will then be inner skin => insulation => DPM => air gap => external wall. Make the floor in the same way suspended off the actual ground. Clip insulation board between the joists under the floorboards again so there is an air gap between the insulation boards and the ground. and insulate the roof. This might seem like a PITA but you will benefit 10 fold. How do I know? I did just this inside the back of my single skin garage. I now have a snug darkroom and office that takes very little heating. Even so, the darkroom, with its dividing door to the office is often <10 degrees if I forget to leave the door open and let the office heat get shared. The office has 2 x PCs which kick out some warmth plus a 3kW oil filled radiator which doesn't get used too much.

If you build in the garden, and don't have running hot water, you will be really struggling. If you do have running hot water but your darkroom is still freezing, you will still be struggling.

Another tip. Make a sink as big as you can fit in. Use exterior ply. Glue and screw it together using one of the high-performance waterproof gun sealant adhesives, and then paint with a couple of coats of two-pack epoxy. The epoxy isn't cheap (~£50) but you'll only do it once!

mr rusty said:

Fill the gap between the studs with polystyrene, or better still rockwool and line with plasterboard/ply or whatever. Your wall will then be inner skin => insulation => DPM => air gap => external wall.

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I'm currently looking at insulation products, and polystyrene is one of the more expensive options. It also gives off toxic fumes should it ever burn. Sheffield Insulation is probably one of the cheaper sources for rockwool. When you go looking for a DPM, ask for a breathable Damp Proof Membrane (for example, Tyvek) and don't use a polyethylene sheet. Doing so will trap moisture inside the building and cause problems in the long term.

breathable Damp Proof Membrane

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Agreed. I got "vapour control membrane" from the builders' merchants intended exactly for this use. I used rockwool between the wall studs and rigid foil faced celotex boards in the roof and floor. It works a treat. I also lined mine in plasterboard and learned to skim with plaster by watching youtube. At the start 90% on the floor 10% on the wall. By the time I'd finished 10% on the floor and 90% on the wall. I'll never make a plasterer but it's pretty good now its all painted up!

Oh yes, and one other thing. If your enlarger is going to be on top of a kitchen unit on top of a suspended floor, consider giving extra support blocks under the floor in the area where the enlarger will be. Stops the thing bouncing around on the suspended floor!

I think it's well worth it. My darkroom is only 60sq feet but it's so therapeutic making art.

Thank you all, unfortunately finances are a major constraint these days as I have ended up out of work due to health (the usual money with no time, or time with no money). The majority of the build will be done with recycled materials from the old shed/donation of my mums old kitchen with insulation being the biggest expense (that said though out loft has a good foot of insulation in it, wonder if I could skim a layer off the top).

Although I'm working with an 8x10' structure I imagine the final product will be around 60 square foot once insulation is accounted for, it will certainly be better than working in our rather small bathroom. The main thing is I will be able to enjoy it more often as the set-up/take-down puts me off, if I can leave it all in place it will be easy to nip out for an hour session here and there.

I would support the recommendations for insulation, floor, walls and roof. You have only one chance to install it and that is at the construction stage and the insulation should be as efficient and as thick as you can stretch to. The most efficient insulation is Celotex much better than polystyrene or rock wool but also more expensive. I built a shed in my garden for a darkroom and just wish I had put in more insulation but it is not possible now.

Tony

The extra £150 spent now on DPM+insulation will make a huge difference to comfort levels over the coming years.

Simple is good. Tar paper, plywood, caulk, and paint should do it. Never mind the cabinetry joints, just butt things up and screw it together w/ plenty of glue and caulk. Then roller paint it. I live in Florida, so there's no need for insulation. However, there's a need for a/c, which is why my darkroom is still the bathroom.

One trick I learned from having numerous contractors fleece me was to use good long screws instead of nails. Much sturdier, and you can put things together quickly w/ a power drill that has a screwdriver bit chucked up in it. Makes it a lot easier to take apart and set up someplace else if you move too.