CHIKO hanger bolt apply to install on both wooden rafter and steel purlin. Both types can be applied with L feet and plate.
You may find Chiko hangerbolt with L feet is very popular in Southeast Asia with its undamage installation. Here is another project in Chiengmai, Thailand, even the roof is very old.
Good waterproof and seal function.
Chiko hangerbolt can protect the roof and install perfect with CHIKO #7 rails for wavy tin roof.
It is economic & time saving due to the high preassemble, almost no limited by roof area.