The minimum size of any building drain serving a water closet shall be 3 inches.
Upc roof drain sizing.
A minimum 4 inch vertical drain is required.
When sizing roof drains the limiting factor for the amount of water each drain will carry away is the size of leader therefore increasing leader size decreases the number of drains required.
Roof area is 300 x 500 ft.
Each 4 drain size in a 6 hourly rainfall area will accommodate drainage of 3 070 sq.
What that means is under a heavy rain occurrence the roof drainage piping is pressurized rather than flowing under an open channel flow condition.
In sizing roof drains and storm drainage piping one half of the area of any vertical wall that diverts rainwater to the roof shall be added to the projected roof area for inclusion in calculating the required size of vertical conductors leaders and horizontal storm drainage piping.
Step by step sizing of zurn drains step 1.
The end result is roof drains 6 in.
2 500 4 x 3 75 2 344 sq ft.
Each vertical drain must carry 2 500 sq ft of roof area at 3 75 inches per hour of rainfall.
Calculate total roof area.
300 x 500 150 000 sq.
Enter table 1108 1 until you find a diameter pipe that will carry 2 344 sq ft.
1 inch 25 4 mm 1 inch per foot 83 3 mm m.
1106 5 parapet wall scupper location.
To size the vertical roof drain for the same parameters 5 000 square feet of room area and 6 per hour of rain consult table 1106 2 figure 3.
The maximum number of drainage fixture units connected to a given size of horizontal branch or vertical soil or waste stack shall be determined using table 710 1 2.
According to the chart for 1 8 slope per 12 of pipe for 5 000 square feet of roof area with a 6 per hour of rainfall the required pipe size is 8.
Select a reference of a roof drain size with hourly rainfall together with the roof area square footage you have estimated and then determine from the chart below how many roof drains you require.
In sizing roof drains and storm drainage piping one half of the area of any vertical wall that diverts rainwater to the roof shall be added to the projected roof area for inclusion in calculating the required size of vertical conductors leaders and horizontal storm drainage piping.
To convert to an area for a 4 inch per hour rainfall to enter table 1108 1 do this.
Uniform plumbing code upc.
