Husky only pees when Im not around

Question
Hello, I have a pure bred Siberian Husky, and I'm having trouble getting him house broken.  I got him when he was 3 months old, and he is 4 months old now and will hit 5 in the beginning of May.  I've been having difficulty housebreaking him.  I would take him outside every hour and a half or so, and he'd do his business, and started to learn fairly quick to go outside.  He sits down, and cries or yelps at me when he as to go outside.  However, if I'm not around for me to hear him (I'm at class or taking a shower) he pees or poops on the floor, and will not cry or yelp to my roommates on a consistent basis even though they do take him out when I ask them to.  Is there something I can do to help with this?  Thank you for your time.

Answer
When you are at home, try having your roommates respond to his crying, and take him out and praise him, vs just having YOU do it, so that your dog learns that it's good to let >>them<< know, too!

When you aren't able to keep an eye on him, until he is reliably letting everyone in the home know when he needs to go out, put him in a crate. Take him out to potty just beforehand.