Pto Roof Drain Spacing

Mechanically fasten all tapers using two fasteners per board.

Pto roof drain spacing.

Each vertical drain must carry 2 500 sq ft of roof area at 3 75 inches per hour of rainfall. 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. Taper roof insulation to drain sumps using tapered edge strips. The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures.

Take the roof s total square footage and divide by the total square footage handled by one drain. The result is the number of drains needed. To convert to an area for a 4 inch per hour rainfall to enter table 1108 1 do this. The sizing of roof drains must be large enough to quickly carry away all water entering the roof drains.

A minimum 4 inch vertical drain is required. Z110 green roof drains are available with enclosure heights ranging from 5 to 18 or as specified. 2 500 4 x 3 75 2 344 sq ft. The roof drain or gutter or drain piping or downspout leader size diameter other size constraints e g.

Enter table 1108 1 until you find a diameter pipe that will carry 2 344 sq ft. Intensive layered green roof intensive green roofs have a deeper soil depth therefore the roof drain enclosure height is typically 12 or more. If insulation layer is 1 or less taper 12 from the drain bowl. For example in the u k.

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. An additional roof drain should be added for each 10 000 square foot area. 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. A good rule to follow is to provide two roof drains for a total roof area less than 10 000 square feet.

Typical range 0 25 to 0 5 inches day. The drainage coefficient is the design capacity of the drainage system and is typically expressed as a depth of water removed in 24 hours inches day. 50 000 4 400 11 36. The required parameters for the drain spacing calculator with typical values for the upper midwest and a reference diagram are as follows.

Or 12 drains required. Z110 green roof drain shown with 18 height for intensive green roofing applications. Designers specify compliance with bs en 12056 3 2000 that includes a calculation for the allowable capacity of the rainwater pipes.