Since this is a male dog it may not be urinating but marking territory. Dogs will often do this , especially if they are not fixed. Having the dog neutered can cut this act in half.
You are going to have to clean the spot with a cleaner made for dog urine or the dog will always be attracted back to it. Once that is done you can sprinkle around his dry kibble in the area as dogs do not like to eliminate where they eat and sleep.
If this is not a marking problem then it is back to potty training basics. Give plenty of routine outings and praise and treat for all outside elimination to further reinforce that behavior. Use human food as the reward if possible. (hot dog pieces, cheese etc.)
Confine him, by gating or tethering , to one room in the house until his habit is broken. If you are working around the house you can tether him to you so he does not have the chance to make the mistake. Punishment in these cases do no good and cause more problems in the long run.
I am going to direct you to a couple of sites regarding this that may further help you.