Double Vanity Drain Pipe Size

Below our tables 1 and 2 summarize common plumbing code specifications for fixture venting and vent pipe sizes and distances that a plumbing fixture can be located horizontally from the vent stack.

Double vanity drain pipe size.

Some older sinks may have drains that connect to a 1 1 4 inch tailpiece but most modern drains have a 1 1 2 inch outlet. Water runs down the sink drain into a p trap so called because it s shaped like the letter which fills up with water to prevent sewer gases and odors. This is the minimum size to use for building sewer or drain pipe that is connected to the toilet. For example if two pipes are specified to be 10 inches apart you measure 10 inches between the centers of the pipes not 10 inches between the edges of the pipes.

The bathroom sink s water lines are roughed in 3 inches above the drain. Minimum drain line size for a double bathroom sink vanity. Therefore a 1 1 2 inch drain will accommodate a double bathroom sink vanity. As with the term on center which is used for construction the term centerline is an imaginary vertical line drawn through a key reference point usually the drain pipe.

Bathroom vanity with cooper sink. Measure 21 inches approximately above the finished floor. A single bathroom sink lavatory drain is 1 drain fixture unit. Make sure you follow p3005 1 drainage fittings and connections and the reference table p3005 1 which specifies the proper pipe connections fittings to use to connect it all together.

This line empties into a 3 line after about 10 feet and has a drop of over 6. The last size is 4 inch drain pipe that can be connected to 160 units in horizontal stack and 240 units in vertical stack. All the pipes that connect to the tailpiece including the p trap assembly. I am replacing a single sink vanity with a double sink.

This diagram of a typical dwv system is called a plumbing tree. A double vanity can offer a his and hers sink. This pipe size is commonly used for sanitary drainage. The current drain line in the crawl space is 1 1 2.

Cut the tailpiece extending vertically down from each drain using a hacksaw so the pipe that extends from it can maintain a downward slope. Also notice the drain is centered right in the middle of this 30 inch vanity. You ll see these distances also in our sketch at left. You probably haven t spent much time observing the pipes beneath your vanity but take a look and this is what you ll see.