Thanks blup, that's the plan :)
Found out that M10 Thunderbolts have a shear strength of 4300kg, so I reckon 1 pair per hanger should be plenty - sounds like M8 would probably work fine but will stick to M10
Looking to use space above bathroom for storage, its 2.8 wide (beam length) and about 4m long
Currently has 3x2 "beams" at 18" centres holding up the bathroom ceiling - so its not really usable for storing stuff
Plan is to add 6x2 C16 joists with 47x147 hangers bolted to the walls - slight...