Share of freehold - how long before I must agree to repairs

arciere

I live in a converted flat with 2 flats in total and 4 owners (2+2). We also own a share of the freehold (joint freeholders, no company).

Recently, we've had an issue with a pipe leaking from our flat (first floor). This was fixed and a claim was filled in with the insurance company. However, the owners of the downstairs flat blocked the claim (because they say it will increase the premium next year). We paid thousand of pounds ourselves to fix the issue (that is covered by the insurance), obviously, but now we can't claim the money back. Besides, we've also been victim of some violent acts by one of the owners downstairs.

Fast forward a few weeks, and with that said, we now seem to have a very minor leak that seems to be coming from the roof all the way down to the downstairs property (it doesn't seem to be affecting us) alongside a waste pipe. According to the builder, who also fixed the previous leak, this is a totally separate issue.

Today, while I was working from home, I received a 30 minute notice from one of the owners downstairs saying that someone was coming to survey the roof. After a 10-15 minute inspection, they knocked on our door and the builder explained very briefly what the situation was (nothing drastic, but some improvements as there's likely to be a small leak somewhere). I was pretty much asked on the spot to agree to the repairs "because we're in the area today and it will be cheaper".

Obviously I said that I couldn't agree on anything on the spot and that I needed time to discuss with my wife too. But my question is, given the extremely rude and violent behaviour of the neighbours (it's not just the leak thing, there are so many other things, feel free to check any of my previous threads), how much time do I actually have before I must agree to the works?