Unique Shower Vent Pipe Size

The required size of the drain shall be determined in accordance with Chapter 30.

Shower vent pipe size. The table indicates that the minimum slope for a building drain with 44 dfu is 18 per one foot of pipe and the minimum pipe diameter at 18 slope is 4 Finally you can use IPC Table 9161 see Figure 4 to size vent piping using the dfu values from step one and waste stack sizes from steps two and three. If the vent wall is parallel to the drain pipe install a 45-degree reducing Y and a street elbow to point toward the wall. A 3- or 4-inch duct connects to the outlet on the fan housing and runs to a side wall or to the roof and connects to a vent.

Vent pipes shall be not less than 1 1 4 inches 32 mm in diameter. In many an older home this drain pipe is perhaps 4 inches in diameter and stays that size all the way through the roof. The required vent shall be a dry vent that connects to the building drain or an extension of a drain that connects to the building drain.

Any increase in the size of the vent shall be made inside the structure a minimum of 1 foot 305 mm below the roof or inside the wall. The vent system serving each building drain shall have at least one vent pipe that extends to the outdoors. A bath vent fan duct that is too long may restrict air flow such that the fan is not functional.

Toilet Vent Option 2. Then the tubshower drain pipe and sink drain pipe are vented with 15-inch pipe and these branch off the toilet pipe. Such vent shall not be an island fixture vent as allowed by Section 913.

It also allows fresh air into the plumbing system to help water flow smoothly through the drain pipes. For a wet vent the vent should enter the drain line at a minimum of a 45-degree angle. A bath vent fan duct that is too short may violate the manufacturers installation instructions may not work properly or may be drafty.

In the IPC toilet vents are 15 in the UPC its 2 inches. Most 50 CFM fans will run well with 4-inch round duct. One popular way to meet this requirement is by plumbing one toilet with a 3 or 4 inch vent.