cat pooping in basement. Help!

As some of you may know, we just built a new house with a concrete basement. We just built the stairs and have been leaving the door open for the cats because it gives them a place to escape the dogs. I realized after a few days that we needed litter boxes down there (I figured they would be able to walk upstairs to their boxes, but apparently, I was wrong). We now have 2 boxes in the basement, and 4 upstairs but we are still finding poop, mainly in between the studs (basement is unfinished). Thats where it was before and scrubed after the first time...we sprayed it with Boundary after the second time. The third time, we sprayed it with a spray that is supposed to take animal odors out of everything, even concrete. And they are still going! In the same places!!! The thing that really makes me mad is the litter boxes I put in the basement are only filled with pee! No POOP! They haven't peed on the floor once, that I can find (and with a drying basement, you can see EVERY bit of moisture!). As of now, they are banned from the basement, but I hate to do that because they love it down there so much.

What can I do? Any suggestions?????

Oh my!! I wish I could help you. All I can do is offer you some hugs and good luck vibes!! If I could get Lilly to stop peeing in my vents that would be a blessing!!

Thanks for the support! I remember reading about your kitty peeing in the vents. That must be SO much fun! I know they aren't hurting anything right now since its concrete but I don't want them to get in the habit since we are planning to finish the basement with carpet and everything.

Sounds like you have your hands full! Good luck!

Can you put the litter boxes in the exact spot they are pooping? For some reason that spot smells right to them and if the box was covering it they might use it

There is some great pet odor remover you can find at pet stores. We had moved to a house that had cat pee ALL over the carpet. The carpet was taken out but the wood under was soaked and stained! We cleaned the wood floor with this solution and the smell was gone and the cats never peed on the floor again. Go the the pet shop, it comes in a gallon sized jug, clean up the cement with it, cement does soak up smells and moisture. I think that should work?!...... I notice you used one kind of odor remover, give me a day or so and I'll find out the name of the stuff we used.