Christian:
I did a lot of research into the most appropriate flooring I could install in my apartments before I chose vinyl composition tiles. You see, I own a 21 unit apartment block that had old worn out linoleum tiles and I knew they were already in need of replacement when I bought the building in 1986. And, of course, I didn't want to be kicking myself for not doing my homework and regretting the flooring choice I'd made and ending up with a mixture of different kinds of flooring in my apartments. Basically, I was looking for the most appropriate flooring for an apartment, not for a house, and there is a difference. Apartments are vacated every few years and the provides for better maintenance of the whole floor.
I chose Armstrong Excelon vinyl composition tiles in the commercial (1/8" thickness) and applied both sealer and finish to them. You can see pictures of the floors I've done anywhere from 5 to 20 years ago on my web site at:
Apartment rentals in Winnipeg, Manitoba
CONS of VCT tile floors:
1. The do require proper maintenance
That can be anything from scrubbing them down the high traffic areas by hand with a green Scotchbrite pad every 5 to 10 years and applying more sealer to a regular scrub and recoat every couple of years using a floor machine.
2. They simply aren't the most attractive flooring you can install.
PROS of VCT tile floors:
1. MUCH more durable than sheet vinyl (including Marmoleum), but not as durable as ceramic tile.
2. Repairability. In many cases damage to individual tiles can be invisibly repaired, and if push comes to shove, damaged tiles can be replaced.
3. Longetivity - If a VCT floor is properly maintained, then unlike other types of flooring, shoe leather will never come into contact with the tile itself. There will always be a coating of acrylic sealer and/or finish between the tile's surface and the dirty and abrasive shoe leather. It is this coating that requires periodic maintenance, so that there is never any wear on the tiles themselves. As a result, VCT tile floors can be made to last indefinitely because that coating over the tile is continually repaired or relaced. It's like asking how long a floor will last if you keep replacing the carpets on it as they wear out.
I'm very happy with my choice of flooring. HOWEVER, in my case, tenants will vacate apartments every 2 to 5 years or so, and that gives me the opportunity to go into that empty suite and machine scrub the whole floor down with a floor machine. That scrubbing removes the dirt embedded surface layer of the finish. I then mop on several coats of new finish to replace the finish scrubbed off, and the floor looks brand new again. I regularily have prospective tenants viewing my suites ask if the floor was brand new? (To which I typically answer: "Almost, it's only about 15 years old.")
When my sister needed new flooring for her kitchen, I installed VCT tile. I knew she didn't have the time to be maintaining the floor, so instead of putting on 4 coats of sealer and 8 coats of finish, I put on 12 coats of sealer. Sealer is put down to protect the tiles from stains. It can't really be maintained because it's so hard that it doesn't respond to polishing. Any janitorial company with a floor machine can strip it off, but it's not meant to be stripped off except if new flooring is intended to be glued down over the VCT tiles. With only sealer on the VCT tile floor, you simply wait for an area of your floor to start looking "dirty". That indicates that the sealer is worn off and dirt is starting to get embedded in the VCT tiles themselves. You then take a green 3M scotchbrite pad or a Magic Eraser and scrub the surface of the VCT tile clean, and apply another 12 coats of sealer in that area. Typically, it's only the traffic areas that get worn off, so it's typically only the traffic areas that are maintained by replacing the sealer. In my sister's case, it took about 10 years after the installation that we first scrubbed and recoat one area with new sealer, and that was in the entrance to her dining room; a very heavy traffic spot. She has two boys, and those boys used to roller blade and play ball hockey on her floor (cuz the rest of her house was carpeted). She's had a dog and two cats for most of the time she's had that VCT tile floor. And, about 5 years ago, my other sister needed a new flooring over her basement concrete flloor. That other sister ended up having VCT tiles installed largely on the recommendation of my first sister.
To answer some of your questions:
WATER SPILLS: I have VCT floors in all the kitchens, dining rooms and bedrooms in the apartment block and I've never had tiles lift as a result of water spills. (I have sheet vinyl in my bathrooms.) I have had the odd tile lift a bit in some areas (bedrooms, say) after a dozen years or so and I just stick those tiles back down. I just use a 15 watt mullion heater for a fridge, put it over the area that's lifting, put some insulation on top to keep the heat going down into the tile, place a weight on top of the insulation (to keep the tile pressed down tight while the old glue softens) and leave it overnight like that. In the morning, that tile will be stuck down as well as it was a dozen years ago.
DOG CLAWS:
VCT tiles are probably your best choice for flooring that'll stand up to dog claws. VCT tiles are actually quite hard. Also, as long as you scrub the dog claw areas once a year or so with a Magic Eraser to clean it and give the floor another few coats of sealer, it'll be the sealer the dogs are scratching off, not the vinyl. And, of course, if you don't maintain the floor, you can always replace the tiles in the damaged area without replacing the whole floor. (Always buy an extra box of tiles as replacement spares.)
QUALITY of TILES:
There are differences between different kinds of vinyl tiles, such as VCT tile, pure vinyl tiling and Peel & Stick, but the difference between one company's VCT tile and another's is minimal. Ditto for pure vinyl and ditto for Peel & Stick. The most durable vinyl tile floor is 1/8 inch thick VCT tile. You can also buy 1/12 inch thick VCT tiles, but almost no one uses them. That's because the major cost factor, the labour to install them is the same regardless of whether the tiles are a bit thicker or not. I used 1/8 inch thick tiles, but I can honestly say that since there's never any wear on the tiles themselves, the 0.080 gauge (1/12th inch thick) tiles would have served me just as well. But, the thicker 1/8 inch tiles are commonly available at home centers, so the 1/12 inch thick ones are harder to find in case you need replacements.
VCT tile is also fairly DIY friendly because the tiles can be cut easily with a jig saw. The fillers in the tiles are abrasive, however, so cutting VCT wears out jig saw blades very quickly.
In 20 years of looking after 21 vinyl composition tile floors, I think I've encountered just about every kind of cleaning/maintenance problem there could be with VCT tile floors. The single major drawback with VCT tile floors is that the sealer/finish coating over the floor needs to be maintained, and the better that coating is maintained the longer the flooring will last. This is why you can find old vinyl asbestos and vinyl composition tiles that still look like a new floor. It's because the sealer/finish wear layer over the tiling has been continually repaired or replaced so that there was never any wear on the tiling itself. Other floorings, like hardwood floors would last just as long if people maintained the polyurethane finish on them, but there simply isn't any technology available by which that could be done the way there is with VCT tile floors.
There is an awful lot to know about installing and maintaining VCT tiles that can't be covered in a single post. However, after having installed and maintained about 9,000 square feet of the stuff over 20 years, I like to think I'm pretty knowledgeable about the subject, so I think I can answer any further questions you may have.