reinforcing roof joisrts for better acess

[muso58]

hi , ive recently bought a 180 + yr old property ,and found the roof joists to have been messed about with .IE cross braces removed ,and replaced with 2x2 box section frames (to walk thru) with steel straps bridging gap from th frame to main roof support. It seems to have done the job but looks a little unorthodox to me!
I was hoping to do it properly by putting new timbers in at a reduced angle to original main beams down to ,the new 9x2 timbers i have just put in (it had 5x2 in) and they had sagged badly due to too much weight in attic space .I suppose my question is ,is there any info available to help me with this .I have seen pictures while surfing of similar ideas ,including a new brace going from new timber base to return to old beams (a kind of a "W" shape.
I realise that a structural surveyor should be consulted ,but money is a bit tight at moment ,and anything would be an improvemnet on situation at moment . I have also seen suggestions that an I beam has been used in some sitiuations along ridge line but im not so happy with this as it would add a lot of weight .I would be happier doing it with substantial new timber and steel plates and bolts .Any guidance pics timber dimensions would be a great help .Thanks for looking

[stoneyboy]

muso58,
You really must get professional help with this. Find a local carpenter who specialises in cut roofs and seek their advice, then decide if you need the services of a surveyor.
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