The root of many a dog's problem behavior is guilt, not his --- yours! You're away all day. You feel terrible that the dog is by himself. When you come home you give your poor puppy a wildly emotional greeting. You play with him for hours. You give him your undivided attention to compensate for your long absence.
Guess what?
You're making it worse for him -- not better! By giving your dog nonstop attention when you're home you are creating a huge contrast between when you are there and when you are not. Basically, you rev him up then... leave.
What can he do? He does what any revved up, red blooded dog does: he chews, barks, digs or dirties. His choices are limited.
To make matters worse, your free, profuse attention can only be interpreted as submission by your puppy. By default that makes him the leader. Most dogs are not cut out for the position and don't fare well with it. Imagine being the head of a company and your employees walk out with no explanation? Think you'd be tense? That's what happens to your poor dog every day when you leave for work.
If you want to make things easier for your dog then do three things.
First, exercise him. A long walk when you come home is the best reward you could give him for patiently awaiting your return and an excellent way to prevent problems.
Second, instead of showering him with attention for doing nothing, have him work for you. Have him sit then pet him. Have him come, then feed him. The more you direct him the more faith he will have in you as the one in charge and the calmer he will be.
Lastly, do a few formal obedience sessions a day for about five minutes each. You'll be amazed just how calming training is for the dog.
You can't make up lost time with your dog by throwing emotion at him. You can make him happier, calmer and more bonded to you by exercising his mind and his body every day.