Yes, you can install skylights on a flat roof. Your roof doesn’t need a slope to install a skylight. While the main issue skylights face on flat roofs is rainwater collecting on top, there are a few options to combat this. First, your installer can build the curb your skylight will sit on so that it sits at a slight angle to allow the water to easily to run off. Another option is to choose a skylight designed for flat roofs. These skylights are created with glass that curves slightly to allow water to flow off the top.
Skylights Made Specifically for Flat Roofs
A curved glass skylight for flat roofs is an ideal skylight as it features a curved edge-to-edge glass or polycarbonate cover that allows rainwater to disperse off the glass while installed on a zero-degree pitch roof. In other words, even if there is no slant at all to your roof, rainwater will not be able to pool on the skylight. Curved glass skylights still maintain the same standard in quality as other flat glass skylights. Some brands even offer warranties to cover any type of damage curved glass skylights may incur.
A curb-mounted skylight is a skylight that is installed on a curb built on the roof rather than installed directly on the roof itself. These curbs can be built at a slight angle so water does not collect on top of the flat fixed skylight. This is typically a more complex installation requiring the installer to potentially do some drywall work on the interior of the home to ensure that the skylight does not leak.
A sun tunnel is perfect for flat roofs as well. Sun tunnels are tubular skylights made of a dome that sits on the roof, a diffuser that connects to your ceiling, and a highly reflective tunnel light travels through. They can be installed on any type of roof, including flat ones.