How does a bioclimatic pergola with a waterproof roof work?

The particularity of bioclimatic pergolas is their adjustable blades. These slats allow you to choose between sun or shade while enjoying natural ventilation. Indeed, if you open the slats of a few degrees, you can be in the shade while believing yourself under the leaves of a tree.

One might think that a bioclimatic pergola would be less waterproof than a roof terrace. This is absolutely not the case, but you must be careful to choose your bioclimatic pergola.

We will explain what are the criteria to buy a quality bioclimatic pergola, and, what makes the difference between a waterproof and non-waterproof bioclimatic pergola.

 Bioclimatic pergola Ombréa 3x4

What are the criteria for buying a quality bioclimatic pergola?


Opt for a pergola designed 100% in aluminum, it is a light, strong, durable material that does not retain water and that does not rust in contact with it unlike steel which risks rusting and is heavy which is a source of dysfunction over time. Aluminum also requires little maintenance. It will be very resistant to bad weather.

Weather resistance

In addition to waterproofing, a pergola must ensure good resistance to wind, rain and snow.

To do this, the structure of the pergola must be taken care of. Wide posts and beams are preferable. Ombréa® pergolas have wide posts of 11 x 11cm and wide horizontal beams of 14 x 7.5 cm.

You should also pay attention to the announced weather resistance. The Ombréa® pergola will resist winds up to 110km/h and will support a snow weight of 55 kg/m²..

What are the criteria for a waterproof bioclimatic pergola?

Some exceptions

First of all, we would like to remind you that a pergola is different from a veranda. Even if bioclimatic pergolas can withstand heavy rain, it is not possible to guarantee 100% waterproofing. In case of exceptional climatic events (strong winds, heavy rains, ...), the waterproofness can be compromised.

Similarly, the waterproofing of lean-to pergolas can be compromised if your home's gutters are not effective. In this case, the pergola will not be able to support additional rainwater. You will also have to pay attention to the junction between the pergola and the facade to which it is attached.

Apart from these exceptional situations, bioclimatic pergolas are waterproof. But, it is important to choose the right model ...

Blade locking system

Bioclimatic pergolas have adjustable slats to regulate the temperature on a terrace. Once the slats are closed, they must be completely waterproof.

Therefore, when buying your pergola, you must pay attention to the construction of the blades.

In order to limit the risk, it is preferable to opt for pergolas with large double-wall slats. Then, the slats must fit into each other. At Ombréa®, the slats are built with "S" shaped ends and will interlock on the other when closed. Small gutters are also integrated on the slats to allow an easier evacuation of water. The closing system is totally hermetic.

Lames orientables Ombréa®

Absence de poutre horizontale

The absence of a horizontal beam limits the risk of rainwater infiltration. Indeed, with a central beam there will be more elements and more chances for water to infiltrate. Continuous slats are preferable for maximum waterproofing.

How does a waterproof pergola work?

The rain that falls on the slats of your pergola, will flow in a controlled way to the side beams, then, will slide in the side gutters (not visible) and will evacuate through the posts then the feet.

It will be necessary to regularly ensure that nothing hinders the flow of water in the gutters (leaves, branches...). It will also be necessary to remove the water which could stagnate around the feet of the pergola (raise the protections).

Here is an explanatory diagram:

Schéma d'évacuation de l'eau pergolas bioclimatiques

To conclude, a bioclimatic pergola can be waterproof. But, you must be careful to make the right choice. You should choose an aluminum pergola, with interlocking blades, without a central beam. At Ombréa®, we have the solution you need!

To consult the different bioclimatic pergolas offered by Ombréa®, we invite you to click ici.