Although residential homes can incorporate flat roofs and commercial buildings often have pitched roofs with traditional asphalt shingles, there are architectural paradigms as to what roof suits the needs of a particular building. In general terms, homes can accommodate a more appealing style which suits the taste of the homeowner while a commercial building requires function over form with a practical design that is proven to hold up under the most dire of weather. There are some more subtle differences in roofing design which distinguish how a roof is built for a house or a commercial building.
Roofs are designed for the building they protect. A typical pitched roof you expect to see on a house follows a proven design which is functional and durable, and therefore looks nice because it is what people from Western Europe and America are accustomed to seeing. Flat roofs on commercial or industrial buildings are also acknowledged for their rugged durability and the practical function of holding HVAC systems or backup generators without using up land the building needs for parking the people who need to conduct business inside. Both roofing styles work well in the American climate and provide the first layer of protection for the house or building on which they are installed.
Residential Roof Replacement
There are new eco-friendly options such as metal or fiberglass roofing, or tile roofs in the Southwest portions of the United States, but the typical home has a pitched roof with asphalt shingles. Such a roof has a designated lifespan based on the idea that normal weather occurs and the homeowner is going to take care of the roof on a regular basis. The roof can last longer with an annual maintenance routine, or not as long if it's never looked at and simply rots away over the years with no further consideration. Regardless, a roof is going to have to be replaced eventually and it's important to discuss options with a professional roofing contractor before deciding what new roof style you want applied to your home.
Commercial Roof Repair
Commercial flat roofs are much more durable over time than asphalt shingles, but require annual maintenance. You may not think wind can move gravel, but it does, and the gravel holding down the rubber sheathing needs to be spread out evenly each year. Exhaust vents, piping, and chimneys are sealed with tar to prevent water from leaking in, and those seals need to be inspected and replaced before a leak starts and causes water damage inside the building. A commercial flat roof will last for as long as you take care of it.