Dimensioning pergola and at least 5.20m long beams (pressure-treated)

[noone70]

Hey

I'm about to build a pergola and plan to use pressure-treated wood.

Two questions:
1. Where in Stockholm can I find pressure-treated timber beams that are at least 5.2m long? The longest I've found is "only" 4.5m.
2. What dimension should I choose for the beams if they need to support a span of about 4.9m? Is 145x45 sufficient?
The only load will be the cross beams and some plants.

 

[noone70]

I've found 5.40 long studs.
But does anyone have any idea what dimension I need?

 

[hantverkare1]

45x145 is more than enough.
Available in 5.40 as you found.

Keep in mind that you need something to absorb the lateral forces. Otherwise, it easily becomes wobbly.

 

[noone70]

Thank you!

Sideways there are no problems, on one end it will be attached to the house wall and on the other end there is also quite good support

Could one go down to 120 studs?