How to Install a Flat Roof Drain

What You'll Need
Shop vacuum
Drain pipe
Flat roof drain
Push broom
Caulking gun
Plastic pastry bag

A flat roof drain is one of the most important features of a flat roof design and they need to be taken care of. If a flat roof drain is too small, it can easily become blocked or simply not be in the right area for accurate draining of pooling water. A flat roof drain can also fail by becoming detached from the roof. Follow the simple steps below to effectively install a flat roof drain.

Step 1 – Clean the Roof

To prevent your new flat roof drain from becoming clogged quickly and to protect yourself as you work, you should always clean off the flat roof. Use a shop vacuum to suck up any puddles of pooling water on the flat roof. Once the water has been removed use the push broom to clear the roof of debris. After you have installed the flat roof drain and it would rain any of the previous debris could block the new drain.

Step 2 – Choose the Location

Where you place your flat roof drain is very important. 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. The most logical place to put the drain is at the lowest area of the roof. Even though it is called a flat roof, it is not actually flat and instead has a very minor slope to it.

Step 3 – Fit the Drain

Use the chisel and hammer to remove bricks from where the flat roof drain will be placed. Never remove more than you absolutely need to in order to make it. Mix up the mortar according to directions, and fill a plastic pastry bag with it and fill the space between the wall and the flat roof drain. You can also use a premade mortar. If you have a wood construction and siding, then pry off the siding and use the saw to remove what you need. Place the flat roof drain and use silicone to seal it around the site.

Step 4 – Downspouts

If at all possible, do not allow water to cascade down the wall of the home. This can cause damage and makes downspouts very important. Downspouts are very simple to install and fit inside the bottom of the flat roof drain. Some use a screw to maintain their placement while others can be crimped by hand. Make sure to install enough downspouts to reach the yard, but then add more pipes to move water away from the foundation of the home. Test the flat roof drain by dumping a bucket of water on the roof.