carolyn get a quote from the roofing company who is doing the work to replace the roof of how much it will cost to insulate the roof, and then submit it as a motion to the OC alongside the quote to replace the roof. This is going to benefit half the owners and state you just need a simple majourity of votes cast for it to be approved (as this is an improvement a Special Resoloution might be required but just hope no-one else realises this)
You could also imply that if the OC dosn’t agree to pay the cost you will consider getting a CTTT ruling that it’s the OC duty to install insulation, and if you win it is going to cost considerably more installing it after the roof has been replaced than if the job was done whilst the roof was being replaced.
My opinion is your chances of winning are 50-50 (depending on how well you present your case) and it will cost you approx $150 to obtain a ruling.