What did their chimney sweep say about the staining?

Don’t burn Blue gum. 

MadEngineer:

 

What did their chimney sweep say about the staining?

 

Don’t burn Blue gum. 

 

Chimney cleaner never mentioned any staining.

Aparently this has been the first load of Blue gum used.

So, I have asked him to take a closer look around the chimney to check if it is actually rust or perhaps resin staining.

If staining, I have suggested doing a test clean with meths or turps... solvents suggested in a Google search.

If it was my roof I'd want to lift the end of the pan flashing to check the roofing iron futher up. It looks like more is happening than is explained by the run off on top of the flashing. Maybe the area just below the flexible boot is already holed.

Get another sweeper. They should be able to advise on that.