Lab/Basset cross is hard on door

[Jackson's mom]

We have a nine-month old lab/basset cross. He is HUGE! He is very hard on the door. He will beat on it until you open it and then turn around and go right back out. Is there a way to train him to quit beating on the door (and ruining it and getting mud all over it)?

[Bernard]

you could try this as your door is damaged yet:
Don't open the door if your dog doesn't sit down
If your dog doesn't stop to beat the door and does not sit, leave the room (not using the same door of course)
Once sitting and before taking the door knot, tell your dog to wait (if needed with a stop sign using your hand)
Take the knot and open very slowly the door, dog should stay and wait (keep the stop sign with your hand at the beginning)
If your dog moves, close the door and begin again the whole flow
If your dog stays waiting nicely until the door is fully opened, then tell your dog "let's go" using your hand simultaneously from stop sign to go sign (just point outside)
Let's go will be the reward