The Pros and Cons of Building an ADU with a Flat Roof

In the construction of an ADU, it is critically important to pay attention to every component, whether it is the foundation, the shape of windows, the layout of the room, or the roof. One of the key roles is played by the choice of the roof because it affects both the appearance of the ADU and the comfort of living. A well-chosen roof can become the main feature of the new ADU.

Architects distinguish more than twenty types of roofs, which differ in the level of inclination, shape, and material. Among all the options, one of the most advantageous and at the same time non-trivial is a flat roof, which has a wide range of possibilities.

In this review, we will talk about the pros and cons of a flat roof for your accessory dwelling unit, as well as reveal some of its hidden properties.

Flat Roof Basics

A flat roof is a roof that has a slope of less than 2.5% and for the human eye, this deviation from the plane is almost imperceptible. Construction costs of such a roof are minimal but do not think that a flat roof is needed only to cover you from rain or sun. Flat roofs belong to the so-called exploited things. In other words, you can use them for various household, design, or entertainment purposes, however, more on this in the next part.

Flat Roof Advantages

There are types of roofs for ADU that fulfill only a direct purpose, however, a flat roof does not belong to this category. This option has a wide range of both construction and practical advantages. In particular, we highlight five main benefits.

Low price tag

Every homeowner is looking for a way to cut the budget for the construction of ADU to direct the saved funds to different businesses. Flat roofs provide such an opportunity, because, firstly, the period of their installation is very short, which means you will not need to pay for the services of builders. Secondly, flat roofs are made of affordable materials. Thirdly, the design of a flat roof is not complicated and there is no more concise and simple option to be found.

Win-win design option

The flat roof opens up the scope of flight for design ideas. The final appearance of a flat roof is very minimalistic, however, its modification can be carried out in any style. A flat roof can be furnished with plants to make something like the Hanging Gardens of Semiramis, you can place beautiful art on the roof, or equip a patio for family dinners with a sunset view.

Multifunctionality

Here we continue the thought on which we ended the last paragraph. Imagine an ordinary sloping roof. How can it be used? There’s no way outside, but inside only as an attic. In the case of a flat roof, we see a different alignment, because the open-air space can serve any purpose. Some homeowners organize a sleeping place on a flat roof, others put table tennis there, and someone performs art in the open air. In general, the functionality of flat roofs is unlimited.

Convenience of Cleaning

With the onset of winter, especially in very snowy areas, there is a need to clean the site, including the roof. In the case of a sloping roof, this is very difficult and, on par with this, a traumatic task, because climbing is risky, and waiting for the snow to fall on someone’s head is also not the most pleasant prospect. With a flat roof, there will be no such problems, you can easily get into it through the upper floor and throw the snow down without risks.

Manufacturability

A flat roof is an ideal space for installing solar panels since the sun’s rays can fall on the entire surface and thus the usage will be maximized. In addition, the installation process also does not require much physical effort, because as we noted earlier, any actions on a flat roof are practically not associated with risks.

Overall, as you can see the decision to install a flat roof can be a winning variant from all sides. Flat roofs will allow you to finish repairs faster, will benefit in everyday life, and will also contribute to the purification of ecology and energy efficiency of residential use.

Flat Roof Disadvantages

Like everything else in our world, flat roofs have several disadvantages. For you to have the most detailed idea about this type of roof, we decided to reveal the nuances that are associated with the weak side.

Here we can focus on four aspects:

Difficult drainage of rainwater. Perhaps the most obvious drawback of flat roofs is the lack of a sufficient angle of inclination for the flow of melt or rainwater. Precipitation falls on the roof and stays there. In the summer, this is not a problem, since everything evaporates quickly under the sun, but in the off-season, it can cause difficulties, so it is necessary to artificially create a slope.
Low insulation capacity. Flat roofs are quite thin, especially in comparison with other types, so in the cold season, you will most likely have to spend more resources for heating them, which in turn will increase the cost of utility bills.
Not Suitable for certain climates. Flat roofs may not be suitable for certain climates, particularly areas with heavy snow or rainfall. In areas with heavy snow, a sloping roof is necessary to prevent the buildup of snow on the roof, which can lead to damage or collapse. In areas with heavy rainfall, a flat roof can lead to drainage issues and potential water damage.
Risks of breakage. Here we again refer to the thickness of flat roofs, which is insufficient in terms of wear resistance. Heavy rainfall, scorching sun, or hail can cause damage to flat roofs, which will reduce their service life. Fortunately, this issue is easy to solve if additional supports are installed on the inside or the top layer is covered with a special protective coating.

On the whole, it is noteworthy that all these disadvantages can be easily wrapped into advantages, for example, you can ask builders to add a layer for extra insulation and then the issue with the lack of insulation will be resolved. This is the main feature of flat roofs for ADU, they are versatile and multifunctional, and these are the most important characteristics for any homeowner.