You may want to check your strata managers agency agreement. I would be very surprised if they have the authority to spend such sums of money with out a committee resolution.
Also, speak with your other committee members and demand regular meetings. OC’s elect EC’s at the AGM to make decisions on their behalf. The Chairmen is not able to make decisions without agreement of the committee despite the fact that he/she may be the designated point of contact between the committee and the strata manager.