How to make waterproof a pergola ?

The polycarbonate or PVC sheet will protect you from the rain and all weather conditions. Your outdoor space would prefer a polycarbonate sheet, as the PVC one is less resistant. However, it's also less expensive. What's more, PVC sheets turn yellow over time, which is not the case with polycarbonate sheets.

How to insulate a pergola from the rain?

Install a roof or awning. This is the most effective way of keeping the rain out of your pergola. You can install a permanent roof or a retractable awning that can be opened and closed as required.
Use weather-resistant materials. When building your pergola, use weather-resistant materials such as cedar or redwood. These woods are naturally resistant to rot and decay, and will help keep your pergola dry even in wet weather.
Seal pergola joints. Be sure to seal all joints on your pergola's roof or awning to prevent water from seeping in. You can use a transparent sealant or a paint specially designed for outdoor use.

How to avoid water pockets on pergolas?

Tilt the roof or awning. The roof or awning of your pergola should be slightly sloped to allow water to run off easily. A slope of 1/8 inch per foot is generally sufficient.
Install gutters and downpipes. If you have a permanent roof, you can install gutters and downpipes to keep water away from your pergola.
Inspect the pergola regularly. Check the pergola roof or awning for signs of deterioration, such as leaks or cracks. If you find any damage, repair it as soon as possible to prevent water from accumulating on the pergola.

How do you strengthen a pergola?

Add diagonal bracing. Diagonal bracing is an excellent way of increasing the strength and stability of a pergola. You can add diagonal bracing to the top of the pergola or to the posts themselves.
Use thicker posts. Using thicker posts will make your pergola stronger and less likely to wobble.
Secure the posts to the ground. Be sure to secure the posts to the ground so that they don't move in high winds.

How to stiffen a wooden pergola?

Use thicker beams. Using thicker beams will make your pergola more rigid and less likely to sag.
Add cross-members. Crossbeams help distribute the weight of the pergola, making it more rigid.
Use metal supports. Metal supports can help connect beams and posts more securely, making the pergola more rigid.

How much weight can a pergola support?

The weight a pergola can support depends on a number of factors, including the size and type of pergola, the materials used and the way it's built. As a general rule, however, a pergola can support a weight of between 45 and 90 kilograms per square meter, depending on its structure.