Any span tables for slightly pitched patio cover?

Are there any span tables I can use for a patio canopy? UK based. It will have polycarbonate roof (probably 16mm). So the only weight would be the roof itself and then need to cater for snow on top. So I guess would be a bit more relaxed compared to tiled pitch roofs, or floors, or decking, that need to carry people. I can only find tables for those, or US based canopy ones like this https://www.hometips.com/buying-guides/maximum-beam-rafter-spans.html. Or various forums where people ask for sizes for their own particular design.

I am building a patio canopy so connected to the house and it will have approx. 5 degree pitch. The beams will span 3.3m, and are C24 6 x 2s. The main beam on the posts holding the roof beams will span 4.8m across, and is also a C24 6 x 2 in my plans.

I initially wanted to centre the beams at 800mm but reading up online maybe they should be 400mm or 600mm for a 3.3m span. The main front 4.8m beam originally was to have a centre post and the two spans will be about 2.2m, but I am also thinking maybe I should have 4 posts, 2 close to each other on the end, to reduce the main span.

Attached is my plan with beams 400mm centre, but the wider I can have them the better to let more sun in.

Problem is I am not sure what tables to use to know for sure. I want to maximise centres.

Thanks

Using 6x2 C24 on a 3.3m span polycarb roof you would be ok with them @ 800 centres.
Your snow load would be around 0.75kN/m2, and your dead load will be minimal. You would best have cross-pieces at mid span to take any bend out of the sheeting, as you have shown.
For the front beam, a 6x2 C24 would probably be OK, but it depends on the span-length in the middle, and the outer two spans.
Your main issue will be fixing the rafters to the main beam to prevent wind uplift.

Thanks for that. I’d like to both the rafters onto the main beam and use brackets to fix them.

do you know of any tables to double check? Probably ok sounds good but I don’t really know what the max span should be. I’d be resting several rafters on that span. If there are none I can also put in some braces too.