Moving collar/rafter ties

[paulharmer]

Hi all, I'm looking for some advice on moving some beam in my loft to make the space a little more useable. It lends itself to a loft conversion but is cost prohibitive at present.
It's a 1930s roof which we are having replaced due to leaks and dust. The loft has beams across every rafter 4.5m in length at a height of 1m. The top of the roof is 2.7m.
I read somewhere that collar ties van be anywhere from 1/3 to 2/3 of the height meaning should be 90cm to 1.8m. if I can move to take each one off and move to the highest point it would make the space more useable.
Have I understood what I read correctly or is there something I'm missing?
I've added pictures which hopefully are useful.
Thanks in advance

 

[ree]

Maybe its best to leave all your roof timbers alone - there has been previous work, possibly remedial work for whatever reason(s): dont mess with it.
It would be possible to re-build the loft & roof under the direction of a SE.
IOW's a fully engineered loft conversion. But you are already having the roof cover replaced?
FWIW: why not get a SE in for a heads up - contact them with an email attachment of the above pics.

 

[freddiemercurystwin]

You'll need a structural engineer to do some number crunching and give you a proposal, it matters not what you have read online or on this forum. Except this post obviously.

 

[paulharmer]

Maybe its best to leave all your roof timbers alone - there has been previous work, possibly remedial work for whatever reason(s): dont mess with it.
It would be possible to re-build the loft & roof under the direction of a SE.
IOW's a fully engineered loft conversion. But you are already having the roof cover replaced?
FWIW: why not get a SE in for a heads up - contact them with an email attachment of the above pics

 

[paulharmer]

Maybe its best to leave all your roof timbers alone - there has been previous work, possibly remedial work for whatever reason(s): dont mess with it.
It would be possible to re-build the loft & roof under the direction of a SE.
IOW's a fully engineered loft conversion. But you are already having the roof cover replaced?
FWIW: why not get a SE in for a heads up - contact them with an email attachment of the above pics.

Thanks, We decide to have tiles and felt installed and also sort out gutters and facias as it was just tiles which meant it was dusty and we had a few of leaks. That's going on now and now we can see the space better had thoughts on the space inside.