In Summary

When it comes to choosing a roof for your home, the last thing you might think of is a flat one. Although often overlooked, you will be surprised at just how many benefits flat roofs have as Derrick Wandera writes.

Simon Mutumba opened up bar on top of his commercial house in Najeera, a Kampala suburb. “I knew the space in the house would not be enough for parking and accommodating the large number of people I anticipated. I decided to use the space atop my house,” says Mutumba.

Why a flat roof
There are several benefits of having a flat roof for your home. Firstly, flat roofs are less expensive than other types. They are quick to construct and require fewer materials which also helps to reduce the costs.
Flat roofs are also safer and more accessible than other types and there is less chance of slipping once you are on top.
Flat roofs are lower in maintenance as there are no slopes or ridges to clean and maintain.
With these roofs, you can use all of the space underneath the roof, and you can even use the surface of the roof itself. Steven Opio says a friend put up a swimming pool on his roof top which saved land and provided for privacy.

Walls
When planning for the walls, Dickens Lubowa, a consultant civil engineer in Katwe, recommends wide walls. “These can be achieved through using big blocks and strong cement. The strength of the roof is paramount because flat roofs can also be used for other purposes, he says.”
Paul Tiboti, a civil engineer, advises the use of blocks rather than bricks for walls that support your flat roof.

Drainage
This is one of the most important features of a flat roof design. If a flat roof drain is too small, it can easily become blocked or simply not be in the right place for accurate draining of water. A flat roof drain can also fail when detached from the roof. Tiboti recommends the following:

Gutters
Gutters are the most common drain system for all types of roofs because they:
• Are inexpensive and are the easiest types of drain systems to get and install.
• Protects doorways and window openings.
• Can keep water from pooling and building up near the building’s foundation.

Inner drains
The drains are usually placed near the centre of the building. They attach to pipes that drain the water down through the building’s roof. This keeps the water away from the walls and foundation preventing cracks.

Scuppers
These are openings in the outer walls along the roof line. They allow water to run through the wall via a metal box protecting and surrounding the scupper.
Tiboti notes that it’s the kind of house that will provide for thermo-installation because it keeps the house aerated.

Areas to watch
The house is costly to build and requires skilled manpower.
Tiboti says you will need strong machines since you are going to use heavy materials. “When roofing a pitched roof house, you can use cheaper materials but with a concrete rooftop, you have no choice but go in for the strong materials,” says Tiboti.

Tips
Roof decks
• Extend your home’s garden with a flat roof deck. If your home is making the most of the available space on the plot, then a flat roof, even one with a garden, can add to your outdoor space.
• If you have a single storey extension to your home, then making the roof a decking area, accessible from the first floor is another fine idea. Not only will you extend the usable space, but you will be able to enjoy the views.