HELOC for Deck rebuild?

So my FIL and wife are co-owners on the home. There’s no financing on the home.

The home itself is in decent shape and we’re not looking to make many updates.

However, we have two large decks on the property that badly need a rebuild.

I don’t know much about HELOCs and was hoping someone could help me out here. Can my wife and I take out like a $50,000 HELOC, pay to have the decks rebuilt and then just pay $100-$150 a month?