Thread: How to plumb in a sink in a garden shed.

Thin walled back poly is not intended for continuous water pressure either, but threaded or compression thick wall black poly can be used.

In 1985 I built a laboratory at work that had to be as metal free as possible. A cyclone rated demountable 6 x 3m shell with ply lining was delivered to us and set up on blocks in a car park. It came with one copper connected tap, a PVC sink and waste connections, couple of power points and lights, but I gutted the lot and started from scratch. I rewired all the electrical - the two breaker box was replaced with a 20 breaker box (13 breakers- every lab hot plate had its own breaker). New plumbing consisted of 2 PVC sinks, and 3 taps in thick black poly. The PVC waste had to be replaced as it needed to be rerouted. I relined the internal walls, constructed the false air return walls and recirculating HEPA air filtration system, benches, fume hoods and acid distillation system, all in HDPE/Polypropylene/Polycarbonate. Testing showed the air inside this lab was as clean as a hospital operating theatre,

When the time came for the Uni plumber to connect the water up he looked through the lab and said - not legal - both because of the materials used and the fact that I did not have a license. I said, - OK I'll strip it all out and you can come back and reinstall it

Suddenly things weren't quite so illegal and he went around the lab pointing out a few small changes - like he didn't like our 2 plastic taps and made us change them for powder coated ones which cost $350 each!
I installed the new taps and then replaced them with the plastic ones after he connected us. Even the plumber recognised that at worst if the system leaked, the water was just going to flow into the car park. The lab was supposed to be a temporary (5 year) operation as we were going to get fancy new labs in another building. However as usual it took 17 years to get the new labs so the lab was in continuous use up until then. No leaks. If I was to do it again I'd use the blue stripe stuff - don't remember it being available back then.

When the old lab was finally replace in 2002 it was gutted and everything inside the lab went into a couple of skips and I score several items from the skips. The still brand new white powder coated goose necked tap, and the sign on the front of the lab.
Now they are both in/on my shed

sink2.jpg Sign2.jpg

Inspiring story. Thanks for that. Enjoyed every bit of it.

Listen I'm in comms with a guy at an irrigation store and he knows exactly what i want, he says, but he won't tell me or show me a picture until I give him the exact measurements of the garden tap and the sink flexy thing.
Even though both of them are pretty standard in Aus.

Do you think you could point me towards a description, maybe p;cs, of what I need to make these connections?

Standard garden taps have a 20mm (3/4”) thread, the bigger chunkier ones are 25mm (1”)

If your flexy thing is standard it will be 15mm (1/2”)connection

Originally Posted by abrogard

Well that sounds pretty great to me. No 'ifs' and 'buts' - just blue line irrigation will do the job.

And fittings are available for each end of it to connect to the two different taps - or the T piece at one end if I put that in?

Every type of fitting and option is readily available including threaded connectors for brass or galvanised fittings so will easily join up to your existing water source and to a tap fitting
Plumbers use this product often

what are they called? any place I can view a selection of them maybe?

I found this place but their pics don't clue me in on what they do, how they do it, which I'd need (if any of them)

Originally Posted by abrogard

what are they called? any place I can view a selection of them maybe?

I found this place but their pics don't clue me in on what they do, how they do it, which I'd need (if any of them)

3G Metric Compression - Philmac

They are on the shelf at Bunnings or any plumbing supplier

Thanks for that. An interesting story. Make it all come to life.

I have another little question maybe not worth asking:

any hints or wrinkles, dangers, advice, about putting the hole in the wall of the tin shed?

I'm thinking there's nothing special. Just do it however you like. But thought I might ask.

I can see there's maybe the possibility of cutting to a size to take available grommets?

Or perhaps cutting so's you get 'spikes' of tin project outwards and lay along the pipe make a better connection - easier to make waterproof, draughtproof?

Nothing, I imagine. But just thought i'd ask while I"m here.

You can pretty up the hole with grommets etc to look nice and perhaps keep out vermin
The poly pipe is extremely resilient and the sharp edges won’t worry it at all if you don’t

Cheap hole saw of the closest size to OD of waste pipe 54mm from memory and slow to moderate speed in a drill, remember to put a bead of silicon around the pipe on the inside of your shed when you finally fit the pipe

That's a good one. Thanks for that.

I just got a quote. For 25mm polypipe with elbows at 25mm too, of course. And they're $13 each.

we need 21m of pipe and

I'm thinking maybe I would be better with 20mm pipe and fittings, if they make it?

The tap the water comes from is 20mm and the flexhose fitting it goes into is 20mm. Though went i sen the young fellow to get me an adapter he came back with a brass 20mm to 25mm.

I don't know why.

I assume there's a difference in threads somewhere along this chain that I don't know about. And that's what this 'adapter' is doing. Changing between the tap hread at 20mm and some other thread ( pipe thread ?) at 25mm. But why go to 25mm ? I wonder if there's any truth in any of that?

But either way it seems silly to have 25mm pipe choked at each end. Not that there's much differenc in the price for my hob - about the same for 21m of 25mm as for 50m of 20mm ( which I have to buy because they don't cut up 20mm)

I think. If I found the right stuff. I googled and found some black polypipe which it said has a blue stripe. But it might be entirely wrong for this job, I don't know.

But there might be a significant difference in fittings costs.

The blue strip denotes potable water use only, the green strip denotes non potable water ie: dam, bore, etc but is still ok to use for potable. If there is a irrigation supplier near you, see them for pipe and fittings, they will cut to required length or nearest metre. Also try one of the specialist plumbing suppliers ie: Reece, Tradelink, etc

Hey thats good to know I was thinking it had more to do about pressure and ability to bear being out in the sun.

Seems like really I could anything at all except garden hose?

And perhaps the while poly we we see everywhere won't take the sun?