4 yr old-needs to be potty trained

Question
I have a bischon frize that is 4 yrs old that was not crate trained as a puppy and needless to say, he has never been potty trained either. I am at a loss for how to correct this aweful behavior that keeps me very busy cleaning my carpets. For example, today he came right from being outside into an area in the home that we normally have baby gated off and went directly over to the couch and peed on the corner. Do you have any suggestions? We have a fenced back yard that I let him go out in but I do not usually go out with him (though I do see him potty out there). Another weird thing is that when he does go potty outside he tends to lift his leg on the leg of the patio chairs or deck railing and he poops on the concrete patio near the fence gate...  

Answer
Hi jen,
sorry for delay there was a problem on all experts and I couldn't sign on

I would definitely confine him until he is house broken.  Remember, dogs need to be house broken in each room.  They must learn to keep their den clean.  when you are not around, put him in a bathroom/laundry room  with his bed and then paper the floor about 4 inches away from the bed.
Hopefully he will start using the papers and also narrow down where he goes.  Now, if he isn't neutered, he may be marking, or if he was neutered late.  In this case, do the same and pick up some sprays that you can use on the furniture to keep him away.  This spray must be renewed frequently.
When he is not in his "den" (the room you have allotted) he must be on leash so you can keep an eye on him and correct him immediately if he even sniffs like he wants to go.
good luck nancy