Best Techniques To Combine Toilet And Sink Drains

The majority of bathrooms have several plumbing appliances, you’ll find a shower, toilet, sink, and in many cases a washing machine. All of these appliances need to be connected to the drains and different size pipes are usually required. For example, the toilet usually uses a 100mm pipe while the wash basin can be as small as 32mm or 40mm.

It’s not practical to run each pipe down through the house and to the sewage system by itself. Instead, all the waste plumbing should connect in the bathroom before moving onto the main sewers.

It is important to note that you aren’t just connecting pipes to take the waste and water away, you also need to create a vent to ensure everything flows smoothly. If you don’t have any experience with this it’s a good idea to contact a reputable Sydney plumber and have them deal with everything for you.

Joining Toilets & Sinks

If you’re going to do this yourself then the first rule to remember is that all waste pipes need to have a downward angle. Equally, all connections between pipes are done after the trap in the appliance. The trap is designed to prevent gases from escaping into your home, it doesn’t smell nice and can be dangerous.

To do the plumbing start with the toilet and work out the route it will take to get to the main sewer pipe. You can add this pipework in. But, it does need to use a ‘T’ junction when heading toward the toilet. One part of this heads straight upward and should be plumbed above the height of the building. It allows air to be sucked in, acting as a vent pipe.

Inside the bathroom, usually under the floorboards, you will be able to create a waste pipe from your shower and sink. These should stay under the floorboards and head directly for the toilet waste.

Remember, there must be a subtle slope in these pipes, ideally ¼ inch drop per foot of pipe. Your aim is to get the sink pipe and the shower pipe to reach the toilet drain pipe within six feet of where the toilet sits.

You can then add a ‘T’ into the toilet pipe. It should be an unequal tee. Two points are the same size as the toilet waste, the other is the same size as your sink or shower waste pipe. This will allow you to slot the shower/sink pipe straight into the unequal tee.

Don’t forget, once you’ve completed a trial run, you’ll need to glue all the PVC waste pipes together. Use the special adhesive you can get in your local store and leave it for at least an hour to set.

All you have to do then is check for leaks.

Showers & Sinks

Depending on the position of your shower and sink it is possible to join these two waste pipes before they connect to the toilet. All you need is a ‘Y’ connector to allow the sink waste to drop into the shower pipe and avoid backflow.