Roof Drain Direction

The most logical place to put the drain is at the lowest area of the roof.

Roof drain direction.

Connecting a trap to a vertical drain with a wye fitting and a 45 degree elbow seems like a good idea. For a large roof it is recommended to have drains placed at multiple locations within the area of the roof. They attach to pipes that drain the water down through the building s roof. The drain is typically placed along the edge of the roof but it can be placed anywhere that you think it will do the most good.

As water drains down the steep slope at the wye it can create a siphon effect such that water will be sucked out of the trap. Since water tends to collect in the center of the roof this can be an effective means of eliminating it. Gutter downspouts often carry huge amounts of water from a large area of the roof. Scuppers are open holes or channels cut into the roof edge or parapet.

These drains are distinguished by having higher rims. This will cause heavy drainage issues from your gutters and downspouts. The end result is roof drains 6 in. Or smaller in size have the ability to flow more water to the piping than the piping can handle using 33 for the vertical and full flow for the horizontal.

In addition to the primary roof drains there will also be overflow drains which are used for redundancy and sized in the same manner. Residential homes may also have this type of commercial roof installed. And the empty trap will allow sewer gas to flow into your home. The flow through the roof drain is very efficient directing the water into the drain.

Roof drains must be firmly secured to the roof with an underdeck clamp otherwise due to snow loads rain loads and reg ular expansion and contraction the drain will work in and out of the roofing causing roofing membranes to flex and fail. Where you place your flat roof drain is very important. The roof is sloped toward the scuppers and water simply drains out through the scuppers. The drainage system of any roof can be located at the edge or in the middle of the roof.

The drains are usually placed near the center of the building. Increasing the angle of a flat roof will always increase the speed of water movement across the surface. An interior drainage system makes use of several drains spaced across the surface of the roof most commonly near its center. Scuppers are commonly used on flat roofs that have a parapet or other type of perimeter barrier enclosing the roof.

Inner drains are found many times on large building roofs.