roof wall plate connecters

hi, i want to convert my attic space into a playroom, nothing fancy. there are two metal bars that span the length of the attic from one wall plate to the other. the problem is this, the wall plate at the front of the house is 18" higher than the back so the metal brace rises to the front of the house preventing me from laying a floor.
the attic structure consists of a two purloins joined together, at some point the roof has been repaired and a new purloin was added to the old one and bolted together. there are two purloin either side of the roof halfway up the rafters. there are no other beams or supports.
is it possible to remove the braces and replace with something else.
is it possible to put heavy duty brackets on the top and underneath the purloin connected to the rafters.
any help would be great...cheers...rob

purloins

Click to expand...

purlins!

really dont think it would be wise to touch the purlins! a photo would be better for more accurate info from some of the other guys in the know.

You need to assess the purpose of these metal ties ie.is there a problem with the structure of the building.Are there any steel plates on the external walls.(are these ties holding the top walls together to prevent collapse outwards).Does the loading on the roof allow too much spread to the eaves.It sounds a bit complicated,but most things have been put there for a purpose.It does not mean to say you can not make ammendments,provided stability is maintained.There is normally something you can do.For example lowering the ties down to within the required floor level.The main consideration is having a triangle structure of the roof being tied across at the eaves(Wall plate level)You can not however play,with the weights and stresses of a building.You probably need someone experienced to have a look at this,perhaps you can find a good local builder,who can offer advise.Look for the Federation of Master Builders sign on a van/cafe.to save a few bob.' I'am sorry to bother you but could you have a quick look and offer me some advise,this might be all that is required rather than pay the expense of a structural engineer.The people who fitted these ties probably never imagined the roof space would ever be used for anything,so probably slotted them through for convenience,as loft conversions are generallya more modern idea.