I have a villain who opens 65%, and flats 3bets 50% of the time.Other 45% he folds and 4bets 5%.

Intuitevely I know I should weight my range towards value heavy.
The question is what is the minimum equity required for me to have against his range in order to maximize overall expectation?

My first thought was I should at least have 50% versus him, but given the fact he is folding too, does it have to be so high?

Any guidelines are very welcome.