How do I stop my dog from urinating on the hardwood floor?

Red or Cajun Pepper should work. Unfortunately it is very hard to teach an old male (dog or human or horse) a new trick.

Bleach???? On wood floors??? Goodness no! They sell a bitter apple spray as a deterant. Works on some dogs but not all. Try one product and giving up??? Obviously you need to take him out more often and/or on a regular schedule and train train train! Here are some sites to get you started!

https://www.dogster.com/dog-training/how-to-deal-with-your-dog-peeing-in-the-house

https://pethelpful.com/dogs/Why-your-dog-keeps-peeing-in-the-same-room-of-your-house-over-and-over

https://www.thesprucepets.com/why-is-dog-peeing-in-the-house-1118305

When in doubt, call a friend or Google! That way you will not cost yourself extra money to repair. Never ever use bleach on hardwood floors.

https://www.dogingtonpost.com/what-to-do-about-dog-urine-on-your-hardwood-floors/

https://www.servicemasterclean.com/blog/residential-clean/how-to-get-dog-or-cat-urine-smell-out-of-hardwood-floors/

If he always goes in the same place, get the dog potty pads and put it in that spot. Once used to the pad, start trying to move it closer and closer to the door slowly. If you can, put a spot of his urine on the pad. I did this to a dog that didn't want to potty train. She was real small and scared of the big dog door. Once she got by the door, one of the big dogs started holding the dog door open for her and no more problem!

Here's a post that might help - https://www.cuteness.com/article/stop-dogs-urinating-floor

I have a 6 month old husky... was not potty trained, I take her out 10 to 12 times a day in 12 hours ... and still pees in the house. On hardwood floor, and now in the crate. You won't win . My dog constantly knows outside, but 30 minutes after inside peed on the the house floor. Tried all methods , don't go sprays, vinegar, bitter Apple, no use. My dog and many world wide dogs have medical issues, or behavior problem... it is a battle, that is hard to conquer. I soaked a towel with vinegar, and wiped it on the inside of the crate liner, to discourage my dog not to pee in crate... I get wait to see if it works... time will tell. Good luck with your dog.. to millions of dog owners, is there a solution? Yes... I believe it is .. but a dog , like a child, can only get mild discipline. Not punishment. If a child wets in his pants, and was not potty trained, it becomes our fault. Same with a dog, , but the training can take a long time... and if you succeed,,,,,the dog will still pee in the house... so we lose... pet owners , it is tough... my five year old female cat, pees on my bed, nowhere else,, still uses the litter box... but I call this a behavior problem. She does not get along with the mother cat... 10 years old. So I continue to wash blankets.