First, get a black light and locate all the areas that are soiled.
Second, go to the pet store and buy a LARGE (gal.) container of the enzymes made for cat pee. Nature's Miracle makes one and there are other brands. You'll need to saturate the subfloor and let it dry thoroughly before sealing, and you'll also need to saturate the carpet, walls and anywhere else the cats could have sprayed.

Your best approach may be to: 1. Remove the offending areas, treat the carpet and sub-floor. 2. Seal the sub-floor. 3. Have the installers return and lay padding and carpet.
If you're a DIY person and intend to only cut out certain sections, then you can pull back the carpet and cut out the padding yourself. That will save the carpet layers having to charge for 2 trips.

Yes, there is padding that has a moisture barrier and replacing it may help. But you may find it more economical to just buy regular padding and replace it as needed. (See link below). Are you planning on replacing only the perimeter of the rooms?
Is the sub-floor concrete or wood?

Here is a link that might be useful: moisture barrier padding

I can only offer sympathy, no solutions for you. A friend of mine had a female cat that peed when she got urinary infections & I had a cat that peed for unknown reasons. We used to say we were going nutty, coming home & sniffing floors, furniture, etc.

It's maddening, & sorry to say wait till it gets really warm out, I would come home & it hit me like a wave of stink. It's awful, I the only thing I can think to do is to take the carpet up....I went through many gallons of natures miracle, it works for an occasional spot, but when you have multiple large areas saturated to the floor underneath, it's like trying to put out a forest fire with a handheld extinguisher. Good luck, hope you find a solution before you go crazy!

Feel for your situation too. I had that issue with a cat once and I had wall-t-wall carpet and padding over wood plank floors. I also did the routine with enzymes. It helped for awhile, but humidity brought it out again. When I ripped the carpet out, it was obvious why. Once a spot becomes an habitual potty area, the wet goes all the way to China. I mean clear into the wood beneath. I had to scrub the wood floors and clean the cracks between the planks and scrub it again. (two hundred year old-growth planks). This would not be feasible in a modern wood floor.

The rug has been gone a year now, and the room has no residual aroma. It's finally OUT. A cat's nose will pick up smell a human's can't. If there is any trace of it, it'll get peed on again. My husband also didn't want smooth floors. I've got him converted. LOL. I don't ever want to go through that again. I'm the one who cleans them, it's my choice. If he wants a rug, a room size area rug will give him the same feeling under foot and warmth. Sorry I can't help, but you've got issues with the urine deeper than you think.

akircher, I sympathize. We ended up replacing all the carpet with tile, which is fine because we live in a warm climate. We scrubbed the concrete several times and painted it with 2 coats of kilz prior to the tile being installed. Doing all of that totally took care of the stench. Nowadays, people are surprised to see the cats because they can't smell them. :o)

We had an 18 year old dog who had lots of accidents. When we got ready to put our house on the market, the carpeting had to be replaced. After tearing out the carpet and padding, we scrubbed, then coated the concrete with kilz as well. Otherwise, the new padding would wick it back up (that's what we were told to do by the carpet cleaning people). It was extra work, but we didn't want the new people to get a stinky surprise on the first hot, humid day in their new house!

In order for Nature's Miracle to work, plenty of the product has to permeate the stain/soiled area. When most people do not have good results, it is because they did not get enough product to the affected area.

We bought a repossessed house 4 years ago. The real estate agent warned us about the odor before we went in the first time. This is in a winterized house in late January---outside temps were in the teens---as were the interior temps inside the house. The smell even at 18 degrees was strong. Strong enough that many people simply turned around and went back out.

The reason for the smell? Previous occupants had at least 5 dogs(three were tied in the back yard) and the other two probably did not go outside at all. Those people lived here for over 4 years. They had removed the carpet from the upstairs, but not the basement. There were literally hundreds of pee stains all over the main floor.

We bought the house, took until April---because I knew I could remediate the odor.

Three gallons of Nature's Miracle later, when the furnace had gotten the inside temps up to 80 degrees---NO odor. None.

Now, a year and a half later, while changing the water heater, a couple gallons of water got loose and soaked the bottom of a wall between the basement storage room and the basement hall---and Boom, odor. Why, I had simply not treated that area. Couple cups of Natures Miracle---odor gone. About two months ago the condensate pump failed and the water again soaked that same area. NO odor.

Three of the neighbors finally got to know us well enough to ask about the odor, one figured we just lived with it like the other family. Invited them in and they could not believe there was no odor at all.

So, the stuff works, as long as it is applied well enough and in ALL the affected areas.

Make sure the cat has no infection or stones.....I would suggest to make sure the food is grain free....I have an 18 year old cat who has stones....has had surgery twice, but then I found out what to feed and to make sure he is getting enough distilled water....wet food is the best bet....but make sure it's grain free....Wellness, Taste of the Wild....as far as the smell and carpet....all the others have great advice....Good Luck!!

I know that you said you aren't looking for solutions, but I lived in a rental house with a bad urine spot and had no luck with the enzyme products, even when I soaked the area, covered them with aluminum foil to prevent them from drying to quickly, etc.

What eventually worked for us was pounds of baking soda. We coated the area in baking soda, worked it into every nook and cranny we could and left it for several days before vacuuming it up. It did control the odor surprisingly well. I can't recall, but we may have done it a couple of times. We lived there for several years afterward.

The one thing I did want to mention, since it sounds like your DH wants carpet again, is to be sure to replace the tack strips as well when you do the carpet. They do not generally replace them, but they are wood and hold the odor. The guy who came to measure for the carpet in the house we own asked why we tore up the tack strips. We told him the house had a bad odor (not pets, I have no real idea what, which is a little scary) and that we were eliminating anything we could that might hold the odor. He said tack strips do in fact hold a lot of odor and especially with pets it's not unusual to replace all your carpet and padding and have the odor rise up again in time because it was in the tack strips. The guys who laid the carpet were a little jerky about having to put in new tack strips, but hey buddy, isn't that your job?

Good advice & I knew nature's miracle was good but not how good - I'm impressed that 3 gallons was all it took. I need to deal with a corner of the basement that was used as a litterbox by PO's.

Sometimes if the pee gets so far down deep into the wood subfloor and even joists it can be a lost cause - youd have to either remove all the wood or apply Kilz to every single surface. Keep fingers crossed that its not that bad - hopefull it would have stayed in upper carpet layers and not soaked downward.

OK, you can't afford new carpet now but you can certainly afford to remove what's there - no? The poor cat, all he knows is if it smells like a litter box, that's where he goes. They operate by smell a lot more than we realize. And texture - carpet is soft like a layer of litter is, so in his mind - he's not doing anything wrong!

I have cheap indoor outdoor carpet from Menards I have laid down on the floors until I can get them refinished. Nothing beautiful but I sure would rather live with that than old peed-on carpet. Because carpet is so absorbent I think you'd probably need a lot more gallons of Natures Miracle than the 3 the one poster used - might as well apply that cost toward new carpet IMHO.

One argument for getting rid of it sooner rather than later - the cat might develop a bad habit and keep thinking carpet is a toilet, even if the smell is gone.

Hope it works out!!!

I have five cats, and before these 5, I had 2. IMHO, you have to lose the carpeting. And, never leave any type of plastic bag/wrap laying around. Having done those two things has forever solved any problems I have had. (Except for the one boy I have, who is fixed, but gets a randy in the Spring and has to be watched closely. Fortunately, I have a cat-fenced yard, so he spends a lot of time out there.) Every time I ever had problems with cats peeing, as soon as I removed the carpet, problem solved. Some of the carpet was not mine to begin with and some of it was brand new. For some reason, it was appealing. No amount of cleaning ever seemed to be enough. I do use Nature's Miracle; I should own stock in the company for all the NM I've bought over the years. For the last 20 years, I've had hardwood floors and area rugs and no problems. Even if I didn't have pets, I would not have carpet. I think it's easier to keep floors and rugs clean.

Below is a link to another recent thread on this subject.
A friend of mine moved into a house with her fiance, after living in a condo with her cats, and one of them starting not using the litterbox. After trying various remedies, her vet suggested that the cat could be stressed, so they put him on anti-depressants (Paxil, I think), and it stopped.

Here is a link that might be useful: Cat peeing outside of box

We had to remedy two crawlspaces that cats were permitted to use as litterboxes.

We cleaned out the crawlspaces with sifters, then spray the dirt down at least 3-4 times, allowing it to dry in between. Amongst our spray solutions were: a mix of dishsoap, water, vinegar, baking soda, and/or Nature's Miracle, and after that just plain Nature's Miracle.

My neutered cat has recently contracted a UTI (Urinary Tract Infection), and started peeing on soft things, since he began associating his litter box with pain. I've found that Dreft (laundry detergent for babies) has started to work wonders! Granted, cat urine is way more potent than baby urine, but the idea is the same.

You'll need:
--Rags/Towels
--Dreft Laundry Stain Remover (to pre-treat the area)
--Dreft Laundry Detergent
--Something to scrub the area with (I use the little brush that came off of an old vacuum)
--Spray bottle

Step 1: Soak up any moisture you can from the area with some of the rags/towels.

Step 2: Spray the Dreft Laundry Stain Remover generously over the area (probably about six inches from the outside of the stain/area incase it spread). Rub it in with a rag and let it sit for about 30 minutes.

Step 3: Mix half a cup of Dreft Laundry Detergent to a gallon of water (use half of those measurements for a smaller area). Place it into a spray bottle and soak the area. Use a towel to absorb the moisture so you don't have any mold/mildew.

Step 4: Keep children/pets off of the area until it's dry. If you are still able to smell the urine, repeat as needed.

My friend had several cats who destroyed her home by peeing. In order to fix it so she could sell it, we had to rip up the carpet, replace the subflooring in all the corners that had been peed in, remove the actual drywall of the wall corners and replace---a real hassle, but it worked.