The result is the number of drains needed.
Roof drain sizing.
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.
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.
The sizing of roof drains must be large enough to quickly carry away all water entering the roof drains.
3 size of leader required.
The first step in sizing a roof drain is to calculate the surface area of the roof that the.
And then determine from the chart below how many roof drains you require.
The four things you will need to know are.
Product name manufacturer color bolt hole style lip to lip bolt to bolt 180 bolt to bolt bolt holes type of bolt used material.
And 4 area handled by each drain.
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.
Each 4 drain size in a 6 hourly rainfall area will accommodate drainage of 3 070 sq.
Factors which affect proper roof drainage are deck slope drain size and placement of drains.
The rain storm the flow of rainwater on the roof surface the ability of the roof drain to move the water from the roof to the piping the vertical piping the horizontal piping and the connection to the point of discharge.
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.
Conventional gutter systems such as those used on most houses are suitable for some low slope roofs.
50 000 4 400 11 36.
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.
Click the table headings to sort by that column.
For the purposes of this appendix the following metric conversions are applicable.
Area roof will require 100 000 3070 32 5 or 33 roof drains for ideal drainage.
Roof water drain types and sizing sizing a roof water drain.
How to measure roof drain parts.
Or 12 drains required.
Take the roof s total square footage and divide by the total square footage handled by one drain.
Zurn makes it easy to size roof drains.
2 total area of roof.
Therefore the 100 000 sq.
1 rate of precipitation.
