Firstly, you need to check the building’s by-laws. It may have a specific by-law about flooring or there may be a renovation by-law for your own Unit that dealt with flooring and noise transmission. Most older buildings would have the “default” recommended by-laws, which includes a by-law that says an owner or occupier must not use their lot or common property in a way that causes a nuisance or hazard.
The Owners Corporation of your building must maintain and repair common property. If the age of the building has led to the floor joists and flooring degrading, so they now allow noise to create a nuisance to other lots, then it’s the responsibility of the Owners Corporation to fix that problem. Namely all 4 owners will share the cost (proportioned by Unit Entitlement).
In practice, noisy floors are a common problem, and are complicated to fix. If the issue can’t be easily resolved by negotiation between you and your neighbour, then escalate the problem to the Owners Corporation, and add it to the agenda of the next general meeting, or strata committee meeting. Discuss how to do this with your strata manager, if you have one. Or call a meeting of all owners to discuss the issue.
What generally then happens, is for the OC to engage a suitable expert, such as a sound engineer, to carry out testing, and provide a report about the noise. They will determine if the noise transmission is a problem (ie, noise is above generally accepted levels) and to determine the likely cause of this. Alternatively, if the flooring is old and suspect, then get a structural engineer to report on that. Then the OC will need to fund, and arrange the necessary repairs.