I need some advice about training my dog.?

I have a 3 year old pomeranian, and I must say he is a real menace lately. He goes to the bathroom in the basement when he is alone and barks when he doesn't get to come up. People say that this is because he doesn't like being down there alone and wants to come join the rest of the family. It is a finished basement so it's not like we lock the dog down in a dirty basement. We go down there all the time but when we come up, he barks. Any advice on how to train him to stop barking and peeing everywhere. We've tried letting him up but he still pees on the carpets and goes into the trashcan and rips stuff up. He really is a menace. We want to try everything we can without getting rid of him.