The most common size pipe for modern drains is 1 1/2 inches in diameter, but there are also 2-inch and 3-inch pipes available. Some older sinks may have even smaller pipes like 1 1/4-inch in diameter but these are not as common. If you have a standard kitchen sink drain, then a 1 1/2-inch pipe is typically sufficient.
There are three common drain sizes for bathroom sinks, 1.25", 1.5" and 1 5/8 (1.625"). You need to select a drain that is the same size or SMALLER than the hole in your sink. For example, if you have a sink with a drain hole of 1.75", than any of the drains 1.25", 1.5", or 1.65" will work.
In the kitchen and bath the standard size in Australia for the plug is 1 3/4 inch. For bathroom vanities the standard size is 1 1/2 inch.
Traps come in 1-1/4 inch (standard bathroom sink) or 1-1/2 inch (standard kitchen sink) inside diameter sizes. Be sure to check so you get the right size replacement at your local store. In this guide we'll show you how to replace a P-trap in a few easy steps.
A 32mm waste pipe is typically used for appliances that present low volumes of water to the system (e.g. small hand basins), while 40mm is normally used for kitchen sinks, showers and baths. 50mm, on the other hand, is large to suit commercial applications or connect multiple waste pipes to a single flowing system.
the simple answer is that basin wastes are 1¼” BSP (32mm), whereas bath and kitchen sink wastes are 1½” BSP (40mm).
40mm – Used under kitchen sinks and also bathroom showers/baths. 50mm – Less popular and usually found in commercial buildings, occasionally seen in larger residential dwellings.
Choosing the Right P-Trap
You'll need to identify the P-Trap you're replacing. Kitchen sink P-Traps come in 1-1/2” standard size, while bathroom sinks use P-Traps of 1-1/4” standard size. The traps also come in different material types such as propylene, ABS, brass (chrome-plated or natural), and PVC.
Bathroom sink P-traps are typically 1 ¼ inches in diameter and kitchen sink P-traps are typically 1 ½ inches in diameter.
Are basin wastes a standard size? Yes, basin wastes are all 1 ¼ inches (32mm) in size but you can find bath/sink wastes that are 40mm.
PVC Pipe Sizes in Australia
The external diameter of the pipe is 34mm. 20mm or ¾ inch pressure PVC pipe (in this case, class 12), has an internal diameter of 23mm with an external diameter of 27mm.
A standard sink hole is 1-½” in diameter and will accommodate most lavatory drains.
Are sink drains universal? Kitchen sink drains have a universal diameter. It doesn't matter if you're using a double-basin sink, or a single-basin sink, the drain hole diameter is 3 and ½ inches. This is larger than a bathroom drain, and the same size as a standard bathroom drain.
Drain Size
A sink drain can't have a larger diameter than the hole in the sink, which can be as small as 1 1/4 inches in a small bar sink. You can make the sink tailpiece, P-trap and extension arm all the same diameter, or you may increase their sizes to 1 1/2 inches, which ensures more efficient draining.
They average at around 510mm to 600mm in length and 450mm to 500mm in width. They typically have a bowl capacity range of 30L, 40L, 45L, and 70L for a larger one. Choosing the right size all depends on your laundry sink needs and the size of your laundry room and countertop space.
The most common PVC pipe sizes are 1½ inches (used as drain pipes for kitchen sinks, bathroom vanity, and tubs), 2 inches (used as drain pipes for washing machines and shower stalls), 3 inches (used in piping toilets), and 4 inches (used to connect homes to sewer system).
Land drain pipes are available in 60mm, 80mm, 100mm, 160mm and 200mm diameters.
Waste Pipes - 32mm for small hand basins, 40mm for sinks, showers, baths, washing machines and dishwashers, 50mm for commercial applications and connecting multiple waste pipes to a single flow.
Basin wastes and traps are 32mm and the pipework should be the same, no harm if you used a 40 to 32mm reducer to take the pipe up a size........but no need...
ABS waste pipes are available in three size options. 32mm is generally used for washbasins and bidets, 40mm is used for baths, showers, kitchen sinks and dishwashers. 50mm waste is commonly used for commercial applications or where a number of waste pipes come together in a single flow.
Easily fits the elbow bend of all 40mm waste pipes. Designed to be installed in standard 52mm core drilled holes.
A 32mm push fit waste pipe. Made from polypropylene, this is a quick and easy way to install waste systems incorporating a push-fit ring seal system. An allowance of a 10mm expansion gap on all push-fit joints is required for the expansion of pipes and fittings in each socket of push-fit systems.