Carport covering cavity filling

Hello,

we have a large carport, on whose roof water unfortunately often stands and does not run off to the drain. I am considering increasing the slope. For this, battens with a slope would have to be placed under the roofing membranes, onto which probably wooden boards or similar and then new roofing membranes would be laid.

Currently, the carport is easy to walk on (for example for snow removal in winter). If I apply the above construction, the battens would have to be laid very closely together to maintain the stability -- or the resulting cavities would have to be filled.

It is a question of weight, but also of the shape of the cavities (wide, low) and also ecology.

What could be used to create such a very light filling that provides walkability under the boards? I thought of mounting foam but am skeptical because of ecology etc.

Does anyone know something better?

Thanks in advance

A

With standard roof battens, which are laid at a distance of 50 cm, you actually get enough stability. If you then place panels with sufficient thickness on the battens, the weight is distributed evenly. Then you don’t need to do extensive cavity sealing.