Roof Drain Sizing

The full flow capacity of a drain is not realized until the water reaches approximately 2 5 above the inlet in a four inch drain and 3 5 in a six inch drain.

Roof drain sizing.

Click the table headings to sort by that column. Conventional gutter systems such as those used on most houses are suitable for some low slope roofs. Area roof will require 100 000 3070 32 5 or 33 roof drains for ideal drainage. Factors which affect proper roof drainage are deck slope drain size and placement of drains.

And then determine from the chart below how many roof drains you require. 1 rate of precipitation. Zurn makes it easy to size roof drains. The first step in sizing a roof drain is to calculate the surface area of the roof that the.

The result is the number of drains needed. The sizing of the roof drainage system must consider all components. Therefore the 100 000 sq. 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.

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. Take the roof s total square footage and divide by the total square footage handled by one drain. Designers specify compliance with bs en 12056 3 2000 that includes a calculation for the allowable capacity of the rainwater pipes. For the purposes of this appendix the following metric conversions are applicable.

Or 12 drains required. 2 total area of roof. 50 000 4 400 11 36. Roof drain system and size the scuppers denoting the required head of water above the scupper for the structural engineer.

For example in the u k. Roof water drain types and sizing sizing a roof water drain. 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. The roof drain or gutter or drain piping or downspout leader size diameter other size constraints e g.

Product name manufacturer color bolt hole style lip to lip bolt to bolt 180 bolt to bolt bolt holes type of bolt used material. How to measure roof drain parts. The four things you will need to know are. 1 in 25 4 mm 1 ft 305 mm 1 ft2 0 0929 m2 100 0 figure a101 1 example roof plan 4 a 101 2 solution.

3 size of leader required. The sizing of roof drains must be large enough to quickly carry away all water entering the roof drains.