Flat roofs aren't just for commercial buildings. We've also installed lots of flat roof systems onto residential structures, such as home additions. If you're in the unique position of choosing a roof design, than you're probably wondering what the advantages and disadvantages are of a flat roof. Depending upon your requirements, desires and budget, a flat roof might suit you well or it might not. If you're considering a flat roof, review the following flat roof advantages and disadvantages.
Flat roof advantages
a. Installation and repair
The same applies to repairing a flat roof system. Patches are available for the various flat roof systems, so it takes less time to repair. If an asphalt shingle needs repaired, for example if a tree branch punctured it, often the surrounding shingles need to be repaired as well. You see, asphalt shingles are layered - half of one shingle is underneath half of the one above it so there's always at least 2 layers of asphalt shingles at any point on your roof.
b. Roof deck
What happens when you put anything on a hill? It wants to roll down the hill, doesn't it? Because a flat roof is almost flat, equipment such as air conditioning units can be installed on them.
b. Rooftop patio or garden
With a flat roof, you have the option of having a rooftop deck or patio. When designing your flat roof with your general contractor or structural engineer, be sure to mention you want a rooftop deck because some changes will need to be made, but at least you have the option.
3. Low profile
It's much safer and easier to walk on a flat roof since they're basically flat. Because sloped roofs are often at least 3/12, or 14º, there's a greater risk of slipping and falling.
Flat roof disadvantages
This is a matter of opinion, but some think flat roofs are less stylish. In the mid 1900s, flat roofs were popular. Today, although they are less popular than sloped roofs, they are seeing a come-back (can I call it a come-back?)
Flat roofs have a tendency to be less stable, especially large flat roofs. The larger the flat roof, the less stable it is. To compensate, additional structural stability must be built-in to other areas of the building.
Flat roofs do not drain as well as sloped roofs. The greater the slope, the fast water runs down it. Water tends to pool on flat roofs. Pooling water tends to break down the roofing material. Also, extra precautions need to be taken to ensure seals are made around pipes and flashing.
4. Less space inside
5. Less insulation
Again, because there's no sloped roof and therefore no attic, there's less insulation space. Insulation is basically empty space between the undesirable (the outside) space and the desirable space (the inside). With a sloped roof, that insulation is your attic. With a flat roof, there is significantly less insulation. As a result, your home or building might be effected by extreme fluctuating temperatures.
If you're building a new commercial structure or home addition, you need to consider whether you're going to have heavy equipment on your roof, or if you're going to have a rooftop patio or garden. You can install heavy equipment onto a sloped roof, but it is more difficult, and it can be more difficult to get to that heavy equipment. Consider the above flat roof advantages and disadvantages carefully and consult your roofing professional to make sure you get a roof that works for you.