Pitched roofs have become so common on residential properties that children's drawings of their homes rarely lack a triangle on top of a box. But depending on the layout of your home, a flat roof may be more beneficial.

Describing a roof as flat isn't strictly accurate. While the roof may appear to be parallel to the ground, it is actually designed to slope gently away from the home. Dylan Chalk, writing for the real estate company Redfin, says this gentle pitch prevents ponding by allowing water to drain.

Instead of shingles, flat roofs will use a membrane covering to help prevent leaks. According to Angie's List, flat roofs also commonly feature a covering of tar and gravel, copper, or tin. Erin Vaughan, writing for the home sustainability resource Modernize.com, says rubber, PVC, and polypropylene can all help cool the roof and improve your home's energy efficiency.

Flat roofs can open themselves up to creative uses. You might be able to cover them with a deck, offering an elevated place to enjoy summer evenings. They are also good candidates for green roofs, which have vegetation in a growing medium atop the roofing material. These roofs offer extra insulation, cooling properties in the summer, and a good way to control stormwater runoff.

It will typically cost less to build a flat roof than it will to put up a pitched roof. Abbey Roofing, an English company, says flat roofs will require less material and fewer hours of labor to construct. As such, the final bill for the project can be considerably lower.

Pitched roofs will also be much heavier than flat roofs, easing pressure on the foundation and structural supports. However, this may make it more difficult to switch to a pitched roof at a later date.

With flat roofs, it is easier to have the overhang extend a significant distance past the walls. Chalk says larger overhangs will offer more protection for your siding, windows, and other parts of the home. Since the overhang won't be coming down at an angle, it also won't block natural light from entering the home.

In warm climates, reflective material used on flat roofs can be quite effective. Vaughan says roofs with flat or low sloped roofs were more effective than pitched roofs at reflecting heat away from a home, helping to keep the interior cool. Retrofitting a roof for this benefit is also easier than completing the change for a pitched roof.

Since flat roofs are less common on residential properties than pitched roofs, it is important to find a builder who is experienced in this type of construction. Angie's List recommends asking for references to show a builder's previous examples of flat roofs.

Finding out more about the installation process can also help reassure you about the quality of the construction. Chalk says some flat roofs will come with lengthy warranties to guarantee their quality.

One of the biggest disadvantages of a flat roof is maintenance. Leaves and other debris can easily collect on the roof, blocking drainage routes and causing water to puddle. You'll need to inspect the roof periodically to keep it clean and look for any problems.

Since a flat roof won't allow water to run off as easily as a pitched roof, there is a greater possibility of leaks. These can be difficult to find, and may require you to replace the roof more frequently than you need to update a pitched roof.

Flat roofs can also limit the amount of space in a home, since they will cut off a room at the height of the wall. A pitched roof leaves room for an attic or other storage space, and can also make it easier to create rooms with higher ceilings.

Pitched roofs are often the better choice for areas with heavy rainfall or cold winters. Angie's List says flat roofs are more vulnerable to ice dams, which can easily cause leaks.

But even if a flat surface isn't suitable for your home's main roof, it can still work well for other parts of the property. Abbey Roofing says flat roofs can be an easy and effective way to finish garages, porches, and other extensions.