Minimum slope of a flat roof

Have you decided for a flat roof due to lower costs or a modern look? This roof offers many advantages, but it is necessary to know several facts about it, including the minimum slope of the roof.

What are the advantages of a flat roof

These benefits make a flat roof an attractive choice for many owners and builders:

• Lower construction costs – due to simpler construction and less material, a flat roof is cheaper to build.
• Better use of the roof – flat roof offers the possibility to use it as a terrace, garden or ecological green roof.
• Modern look – it gives the building a minimalist modern style, which is preferred in contemporary architecture.
• Easier maintenance – flat roof offers safe access, so maintenance and repair are easier than with a pitched or steep roof.
• Options for technical background – on the roof, it is possible to install solar panels, air conditioning, antennas, satellites and other devices easily.

Of course, you also need to think about the disadvantages of a flat roof, which include mainly the more problematic drainage of rainwater. However, proper waterproofing can easily eliminate this problem. It will also solve the minimal slope of the roof, which will allow the water to drain more easily.

What is the minimum slope of a flat roof

According to the STN 73 1901 standard, a minimum slope of a flat roof of 1° is recommended, i.e. 1.75 %. In practice, however, it is good to make the slope even greater, ideally around 3°.

This ensures efficient drainage of rainwater and prevents the formation of puddles. If the water stands on the roof for a long time, there is a risk of seepage and damage to the structure. High-quality waterproofing and a gutter system should be a matter of course.

Green or vegetation roofs are also an innovative solution, which will help with water drainage and bring many other benefits, such as energy saving, biodiversity support, thermal insulation or air quality improvement.

With the help of good planning, high-quality construction and insulation, a flat roof can be a practical and modern choice for your living.