Roof Joists Noggins or Purlins?

[ManchesterDIY]

Hi,

I am in the process of completing our pergola. But I have had a massive set back. The roof joists twisted after all the hard work of painting and making all the required cuts. So, I have decided to changed. In order to avoid this happening again I know I have to use noggins but I don't like the look of them.

So, I was thinking of putting in a cross beam (I think they are called purlins) which would be notched into the main joists. Would this be enough to stop the joists from twisting?

Thank you.

 

[martin hill]

Hi Again. Put noggins in but use a whole saw to put a pattern in them or crossed noggins from 3 by 2