Barriers to keep raccoons out of my back porch

"Hardware cloth" should stop him. It's available at home and garden centers. Is there something nearby that's attracting raccoon (pet food, etc.)?

What is on your back porch that they are going after? Generally they are in search of food or water. Is there bird seed or pet food? If so, remove it and store elsewhere. In some cases they are looking for a safe place to nap.

I have all kinds of wildlife and have several fig trees. Many backyard fruit trees in my area. They were climbing and eating my figs and the ones that were not ripe, they just tossed. They nibble on the tomatoes and strawberries too. Annoyed the heck out of me so I went out and talked to them. I told them to be more respectful and i am happy to share, but be nice! Yes, it sounds cat lady crazy, but it works. At least for me. Once the dogs start to bark, that scares them off too.

Live trap...if you catch take him for a long ride and release

They have low shock, solar electric fence hook ups now that you may consider. There is also predator urine~ which can stink {for awhile but the essence remains} which for awhile should keep them at bay. You will have to reapply. I mean no disrespect here when I say this~ any type of urine will draw them because of the salt in urine so if you have a dog, cat, or even human...well, you know. You can try hang mothballs in jugs with a V cut into it, put water an inch or so deep and place 3 mothballs in each jug. This may help. PESTCHASERS~ go with the one who has the most highest ratings that have been rated AFTER use. Be sure to have enough to cover the area needed without anything blocking it. They do work. I bought six to keep cats out of my garden. My neighbors hated me because of the peeping sound that went off because they are motion activated and a leaf could set them off but they worked. Be sure to move around just a bit. This may sound a bit cruel but animals don't like sharp objects poking into their feet~ just to get you thinking on that possibility. Hope some of this can help. ~D

Two things I've done to keep them away from trash cans, garden, etc. is to put cotton balls or pads soaked in peppermint oil (6-8 drops each) all around--they don't like the odor of peppermint, and peppermint isn't offensive to most human noses. You could put peppermint cotton balls all around your porch. For another solution, we installed a motion detector spotlight aimed at their favorite spot--they don't enjoy a spotlight hitting them, and we cut back a tree they could use as a bridge to the house. I also liked the idea of hardware cloth over your screens. We used that at every possible vent or screened opening; We learned the hard way to keep raccoons away because they've invaded neighbors' and our attic through the roof vents. They can do tremendous damage, and rectifying it can be a very expensive haz-mat job.

While you’re looking at Hardware Cloth, you might look at chicken wire and cable staple it in the wood framing,

It’s made to keep foxes out and I’d put it over the bug screen.