OSF,
Welcome back, glad you are here.
There comes a point in our life when dealing with an addict is no longer bearable. I think its great that you are "locking" him out, but this is his home. Is he on the lease or on the title of the home? You need to check with the laws of your state if you can keep him out. You might not have any legal course to kick him out.
So you have made a decision that you don't want him in your home, wonderful. Whats your plan? Chances are you can't keep him out, he has lost his job so he will be around 24/7. Can you live with a 24 hour drunk? We are only in control of ourselves, trying to control him is going to be impossible. Is there some place that you and your kids can go, family or friends. He is going to get really really angry with you for defying him. I am not sure you are safe under the same roof.
Back to the plan. Do you have any money stashed away. Do you have copies of all the important papers you need. Do you have a car that you can get out quickly if you need too and is it in your name? Please start thinking about these things and work on an exit strategy. You have to remember, if you leave, you might never be able to get back in. Get a bank account in your name, make sure important bills are in your name and that they go to your email address so he won't keep them from you and get these things turned off for non payment.
Sorry to overwhelm you with these things, but try and think what you want for you and your kids future and how to obtain them. This is not something you need to do in 24 hours unless you are in danger, but start making notes and keep everything under wraps, do not discuss any of this with him, or your kids, you do not want him to know your plan. Please stay safe. We are here to help, keep posting so we know you are ok.