Are you about to build an attached carport? Are you trying to figure out what style of roof will suit your needs? That is a common conundrum. Attached carports typically have one of two different types of roof. These roofs can be single slope (with various angles of slope) or they can be a flat roof. Both types of roofs have distinct advantages and disadvantages.
Most contractors have their own opinions about which type of roof line is better and often their views vary wildly. As far of ease of construction, both roof lines are fairly simple and easy to construct. A single slope carport roof line takes a wee bit more engineering and you have to make sure the angles are precise. Flat roof carport attached carport construction can be slightly more forgiving. Furthermore the cost of building materials for each type of attached carport is very similar (with the exception of building in locales with heavy snow fall which is an issue to be discussed below). There is slightly more roofing material needed for an attached carport with a single slope. However, the additional cost for the additional material is so negligible that it shouldn’t factor into your decision making.
The biggest detractor in building a flat roof carport is dealing with the weather. You need to consider how you will get the rain and the snow off of the roof. If you add a slight slant to the roof, it will help with rainwater runoff but can defeat some of the advantages of a flat roof. Some advanced construction can incorporate rainwater channels into the roof that can direct the rain towards eaves troughs and /or rain barrels. The more troublesome issue is snow. If there is only a light snow fall, then snow really is not much of an issue at all. If there is a heavy snow fall you need to address to additional issues. Firstly, how to remove the snow from the roof and secondly, you must factor the snow load into the engineering of the carport. A flat roof attached carport that is required to hold a few feet of snow will require stronger supports. The additional structural support will add to the costs of construction. Unless you are willing and able to shovel off the roof whenever needed you will have to incur additional costs.
The over whelming advantage of a flat roof attached carport are the additional other options it allows for. The flat roof can provide the base for a second story. This second story can be as simple as a deck or it can be as elaborate as a studio apartment. The second story can be access in various ways. The easiest way is via an external staircase. Alternatively, it can be accessed via a stairway that is internal to the carport. The third and decidedly more complicated manner of accessing the second story would be by building a door through the side of your house. The decision to add a second story does not even have to be made at the time of initial construction of the carport. A second story can be added years later. However, if you think there is a possibility of adding a second story you should add more structural support to the base level and that way keeping your options open.
As you can see there are both pros and cons to building a flat roof on an attached carport.