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.
Toilet drain pipes are usually 3 inches in diameter. Washing machines and laundry sinks generally need 2-inch drain pipes. Shower and bathtub drain pipes are usually 2 inches in diameter. Sinks usually require a 1.5-inch drain pipe.
Traps are made from polypropylene (white or black), ABS (black), PVC (white) or brass (either chrome-plated or natural colored). Traps come in 1-1/4 inch (standard bathroom sink) or 1-1/2 inch (standard kitchen sink) inside diameter sizes.
Regular schedule 40 PVC pipe (here) is perfect for drains and wastewater. Like ABS pipe, PVC pipe is used for drain, waste, and vent piping systems and as insulation for electrical cables.
A standard sink hole is 1-½” in diameter and will accommodate most lavatory drains. This information is listed with drain products.
If you have a standard kitchen sink drain, then a 1 1/2-inch pipe is typically sufficient. However, for a double kitchen sink or a bathroom drain, you may need 2-inch drainage pipes.
PVC piping is generally used as part of a sink, toilet, or shower drain line, though it's sometimes used as a home's main water supply pipe.
The 1½-inch size is used to capture water that might flow out of a kitchen sink, a bathroom vanity or a tub. The two-inch pipe is commonly used to drain a shower stall or washing machine, and it may be used as a vertical stack for a kitchen sink. A three-inch pipe is what's used in homes to pipe toilets.
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.
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.
Whether it's a kitchen or bathroom sink, P-traps function similarly but come in different sizes. For instance, bathroom sink P-traps are typically 1 ¼ inches in diameter, while those for kitchen sinks are typically 1 ½ inches.
The difference between the two traps is simple: the shape. An S-trap flows down from the drain, curves up, then curves back down. The P-trap also flows down from the drain and curves, but the curve finishes on a horizontal pipe that takes the waste out.
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).
Oversized piping may contribute to health risks such as Legionella, sewage clogs, and odor fade.
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.
The “S” trap is prohibited under the Uniform Plumbing Code throughout the United States. This is because the “S” trap will siphon or suck water out from the trap which will end up releasing methane (sewer) gases into the home.
You probably know that drains need to flow downhill into your sewer. But do you know the proper slope? The ideal slope of any drain line is ¼ inch per foot of pipe. In other words, for every foot the pipe travels horizontally, it should be dropping ¼ inch vertically.
All traps need venting in all cases. Without a vent, the water seal in the trap gets sucked out and sewer gases can enter the room. There's also all sorts of examples where someone thought they were providing venting, but done in such a way that clearing the water seal was still a possibility.
What is an Air Gap and Why is it Important? In plumbing, an air gap is a vertical space (usually one inch or more) between the end of a pipe or faucet and the top of a nearby basin or sink. It creates a separation between the water supply and potentially contaminated water in a sink or other plumbing fixture.
Plastic is also a lot cheaper than most metal piping. Despite the immediate benefits, there is always one thing that plastic will never have on metal: it will never last as long. On top of that, while it can resist a lot of heat, it is nowhere near as heat resistant as something like steel.
PVC Pipes
Polyvinyl chloride pipes (PVC) are commonly used as part of a sink, toilet, or shower drain line. Its plastic tubing is ideal for this kind of usage because it protects the water from rust and corrosion better than other types of pipes. This capability also makes PVC pipe incredibly durable.
The exact plug size will then depend on what kind of fitting the drain has, but 1 ¾ inches is usually considered the 'standard' size for modern plugs. Most hardware and DIY stores will offer a range of plugs to fit that size, so you can choose whatever style or colour plug that you wish.
The most commonly used strainers typically range between 3-½ inches to 4-½-inches in diameter. Make sure to size the strainer appropriately to prevent leaks and malfunction. Most sink depths range between ⅛ inch to ⅜ inches.
1.5 bowl sinks make washing up easier by giving you the flexibility of two working drains. They are ideal for multitasking as the smaller bowl can be used for washing or rinsing vegetables while the larger bowl can be used for soaking dishes.