I am installing ducted air conditioning but there is not enough space amongst the trusses for the FCU to fit. I need to remove (modify) the 2 centre braces to make space. The trusses are 550mm spacing and the roof is 17 1/2 degree. Is this a feasible idea?
Modifying a roof truss is a bad idea. All of a trusses components are mutually dependent on each other and work as a system. Wrongly changing one piece renders the entire truss useless. You need an engineer to tell you where and how you can modify it. Hopefully one who designs roof trusses.