What rafters to use for pergola design?

diy_hausdesigns

Hi all 

Just seeking some advice. I'm planning to building a simple pergola (none covered with no purlins). I am unsure whether to use 90x45mm or 140x45mm for the rafters over a 3.8m span

Sketch of plan 

Sketch of the connection

The 90mm looks good and makes the whole project easier to build and manage. Here is a sample with some leftover 90x35.

But I suspect the 140mm may look better despite it taking a bit more time and effort to build.

Would love any input !!?

Dave-1

Afternoon @diy_hausdesigns 

Id definently go with the 140mm, mainly to stop any potential sagging down the track. Are you going to replace the house attachment points or cut the timber to suit?

I think it will bring the corner together nicely, It will provide a bit of shade and just make it feel more contained. Just having a second look at the way you have extended the posts up from the fenceline has me wondering if it may be better spreading the weight down the whole wall instead of just that top section? I know the open pergolla may not appear to be weighty but as soon as it gets wet and windy it will be heavier then what you may think.

Dave