how much ventilation does a flat roof need

How Much Ventilation Does a Flat Roof Need

Many people falsely assume that their roof doesn’t require ventilation. It makes sense, as all of us know that the most humid rooms in the house like the bathroom and kitchen need it. However, we rarely think like that for roofs even though they undoubtedly require ventilation.

That’s also the case with flat roofs. Roof ventilation ensures your home is cooler in the summer and warmer in the winter. It also makes sure the roof lasts for as long as possible

With that in mind, we wanted to talk more about flat roof ventilation in today’s article. Most importantly, we’ll give a definitive answer as to how much ventilation you need for your flat roof.

What Is Flat Roof Ventilation and Why Does It Matter?

Flat roof ventilation comes in many shapes and forms, but it always ensures that there’s a proper amount of air circulation throughout the year. It’s almost always needed, except for houses that already have warm flat roofs.

As for cold flat roofs, which are more common, they need this type of ventilation because they collect higher amounts of condensation during the winter. The homes are much warmer during winter months, and the hot air sticks to the cold roof, which becomes very moist. If you don’t deal with this moisture, the roof will become damaged. That’s because humidity causes dampness to spread over the roof, which causes structural damage. In time, rot develops throughout the roof, which significantly reduces its stability and longevity.

Additionally, dampness can spread to the interior of the house, which leads to more structural problems. 

So, by having flat roof ventilation, you can avoid this problem from ever occurring. As the hot air moves upwards, it won’t stick to the roof. The ventilation will allow it to move outside. However, how much flat roof ventilation do you need to ensure all the hot air escapes?

How Much Flat Roof Ventilation Does Your House Need?

To take care of flat roof ventilation, a thermal insulation layer is first positioned beneath the roof. This ensures that the hot air has a chance to move and finally escape through the air ducts. However, another layer called the vapor control layer needs to be installed. It prevents hot air from sticking to the roof by acting as a sort of barrier between the two. 

Besides these layers, for adequate flat roof ventilation, you also need vents. These can either be made to fit on the roof ridges or stand vertically on the roof like a chimney. It’s essential to have both of these. Plus, you need to have enough of the roof covered with them to allow all the air to have a way to escape the house. 

The exact amount of air vents depends on the type and size of your roof. If you want to find out how many of these vents your roof requires, feel free to schedule a free roofing estimate with 1-800-HANSONS. We do complete roofing jobs, including roof ventilation, and a lot more, so we can help you with everything you need for your roof.