Pergola Joist support brackets

I'm building a pergola and after many iterations in planning it have decided I need to have the upper framework supported by several steel wall brackets. Problem is that it will go between two levels. Bottom level is double brick but top level is timber and therefore unable to support much weight. So, I need to buy some brackets that I will anchor to the double brick wall. The bracket then needs to be offset from the double brick wall about 30mm and needs to be around 500mm higher than the anchor point at which point it needs to support a 150mm x 42mm joist. I've looked everywhere for these brackets but can't find them. Someone suggested I look for those steel brackets that attach outside power lines to your house but I don't know here to find those either. Can anyone help with a suppliers name.

I doubt you will buy them. You usually get them fabricated from an engineering workshop.

BTW why a 30mm offset, sounds too small.

The top level timber wall overhangs the lower brick wall by 30mm. Strange but true! Otherwise I would have simply been able to use a flat piece of steel with a hosting bracket on top to carrying the joist. At the other side of the pergola I will need to offset around guttering so about 150mm offset. I'm thinking you are right about buying them off the shelf. I'll proabbly have to get them made.

Can you use the brackets to support a bearer instead of individual joists - less brackets - also you can use same 150 offsets and have your joists (over the bearer ) overhanging - just beef up the guage of the brackets. - probably need to use some speed brace diagonally across the joists as well.

I think I know what you mean but either way I still have to find the brackets. Thanks for your help.