Fix It

How to replace bathroom basin ?

When I moved into my house 2 years ago, it had one glaring problem…. a strip of rust around the front of the bathroom basin. Because I’m not the best at prioritising things (and there happened to be some great sales on Steam, and I have 2 young kids, etc etc), my solution was to put a piece of white duct tape over it for 2 years and get on with my life.

I happened to impulse buy a sink a few weeks ago (I had the old sink measurements saved on my phone!), I decided to have a go at installing it.


You only need two tools for this:

  • 2 adjustable spanners (wrench for our friends in the US and Canada)
  • a paddle pop stick (yes really)
  • a spray bottle

material list for replace bathroom basin


It’s surprisingly easy to stuff this up. Learn from my stupidity…

Measure twice

Most import, make sure you have measured the basin accurately! I thought I had, but actually hadn’t – so I had to rush to Bunnings 30 minutes before closing.

Check your connectors

Make sure you have the right hose/pipe fittings! I didn’t the first time. My taps and my water connection both had *female* fittings – so it was off to bunnings again for a coupler (those 2 things in the middle of the photo)

Time to fit that basin!

1- Take a final look at your old sink, yes that is duct tape. Yes, I am embarrassed.

2- Turn your water off. Some of you will be lucky enough to have a tap under your sink to do this. I don’t, so I had to shut off supply for the whole house.

3- The old sink may have a few clips holding in place underneath. Undo those. The old tapware will (hopefully) have braided lines with screw on connections. These can be removed with a shifter spanner. If you have copper lines that are soldered in place, you are going to need a plumber to replace them with braided lines.

Once the taps are disconnected, and any screws undone, unscrew the pipe connected to the drain. I found wrapping a rag around it helped me get enough grip to unscrew it. If you are wondering, that is rust around my old sink.

4- Before putting your new basin ready, we need to fit the tap and drain. Before you do that, measure the old sink hole to check the new basin will fit.

Your new tap will look something like this, with two braided lines (hot and cold).

5- Slide the braided lines from the tap through the hole in the sink. Note in the photo the brass nut. That has to end up underneath the sink. Once you have done that, use the shifter spanner to tighten that brass nut. The idea is that you tighten it just enough to stop the tap rotating. If you over tighten, the sink will crack, so go easy here mate.

6- Screw the drain into the bottom of the basin. Some basins come with a drain, some have to be purchased separately. Generally, they all require you to push the drain in from the top, and then screw one or more plastic rings onto the bottom (sometimes with a rubber washer between the sink and screw on ring.)

7- Now you can settle your sink into place. Connect up your braided lines first. I hit a snag here. Both ends of the braided line had female connectors. This is where I had to go back to Bunnings and get a female-to-female coupler.

Once you have done that, it’s time to connect the drain. Notice something about the pipes under my sink? They suck. Yeah, they probably could be fixed, but a new trap is all of $5. Do yourself a favour and buy one.

8- This is in the new trap, ain’t she a beauty. If you are wondering, this is an S-Trap. An S-Trap does a full S, with the entrance pointing up, and the exit pointing down. If the exit points sideways, you have a P-Trap.

9- Here is the new trap plumbed in. On the bottom left, I used a 90 degree bend with an inspection opening. The inspection opening is handy if anything gets stuck in the bend or I need to clean the pipe. I also used a straight section of pipe and joined it to the existing with a slip coupling. Anything that can’t be screwed together is held in place with plumbers cement – that blue glue seen in the picture. For cutting pipes, a hacksaw works best.

10- Nearly done, but missing one thing – silicone!
(Note: you may notice that the basin has mysteriously changed between here and step 6. I had to swap it with a different basin because I didn’t measure properly, and the first basin was too small!)

11- I used Parfix Bathroom and Kitchen silicone, with the cheap $5 caulking gun from Bunnings. Make sure the area is dry before you start. You will need more than you think – we are going to wipe the excess off and smooth it after application. You want enough to fill the gap between the basin and the bench top. After you run the initial ring around the basin, spray it with a light mist of dish washing detergent and water.

Use a paddle pop stick over the silicone to give it a nice smooth edge. You will need to wipe the excess off on a rag pretty frequently. This detergent stops the silicone from bonding with the paddlepop stick.

12- Ta-Da!

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