partner drinking problem

Me and my partner are madly in love but the one thing that lets him down is his drinking. He works sat/sun/mon/tues and when he gets home on tues he drinks straight away and won't get home till about 6am the following morning. He goes out by himself and drinks constantly. He gets himself into situations too whenever he is out drinking. I'm not a drinker myself so I don't see why he feels the need to drink from Tuesday onwards after work. It annoys me because we are newly engaged and just got a house together and about 50% of the time I'm by myself whilst he's out drinking. I've tried to talk to him about it but he doesn't seem to understand. Any advice I can take :(