I have a bathroom (at the church I belong to) that has a hard type of vinyl tile in it. A toilet has overflowed 2 times in the past and flooded the floor. As a result, a lot of the tile has come loose. I have the replacement VINYL tile, but need to know how to continue. Under the tile is black adhesive that was laid on a concrete floor. I searched prior forums for info and have an idea what I may be up against, but am not sure. Can I lay the new vinyl tile over that black adhesive without causing any problems? I know it must be free of bumps. If I can - great! If not, do I really need to remove all the prior adhesive? This is a ladies bathroom with four stalls and it a lot of surface area to tackle. Also - does the black adhesive potentially contain asbestos - it was laid in the around 1990. Any info you may be able to direct my way would be greatly appreciated.

If the tiles are 8"x8" these are ore than likely asbestos tiles. You say the tiles have been installed in the 90's so this is unlikely. (same with the adhesive)
What you may have is a VCT or Vinyl Composite Tile. These are thick 12"x12" tiles that are glued down instead of "peel and stick". You see these in hospitals, schools, commercial buildings, etc. You can purchase these at Home Depot or Lowe's.

As for re-installation, try scraping the black adhesive up or knock down the rdiges of the glue. These type of tile are usually installed w/ tile contact cement. Purchase an adhesive rated for concrete installation. If you can't budge the old glue, I see no other choice except for just re-gluing over the old stuff.

They are the 12 x 12 thick tiles and definitely not the peel and stick type. The tile is in a ladies room in a church and is definitely a commercial grade so it does sounds like the VCT. Read about the stuff, just didn't know the name. I have the replacement tiles, but now I need to get the "tile contact cement". I also need to get the old ones up first since I plan on replacing all the tiles. A lot are loose, but a fair amount are not.

Do you know off hand how long it takes for the floor to set before it can be walked on? It is a rather busy church and I will not have a lot of time for the whole process. I need to make sure to plan accordingly.

Thank you for your prompt answer. It is greatly appreciated and a tremendous help!

When you put the contact flooring adhesive down it has to be dry to the touch. Usually about 15 min to 1/2 hr depending on the humidity and how thick you put it on. I've installed adhesive on large floor areas with a roller or it can be installed with a fine knotch trowel. The brand I use is Parabond Vinyl Tile Adhesive.
Once the adhesive is dry, start sticking the tiles down. You can walk on it immediately.
It is recommended that you rent a flooring roller. This is about a 80lb roller that you roller over the tile to help make sure all areas of the tiles are stuck. Again this can be done as soon as you install the tile.

Skiberger - you have been a wealth of information for me. Obviously, I am a newbie at a lot of the fixing the church needs done. Would love to contract it out, but funds are an issue. I have to save them for all the things I definitely cannot do - like boilers! If you think of anything else a novice should know - I am all ears (or should I say eyes)! Thanks again for all your help.

We removed 1979 VCT tile for the gym at our church... there is black adhesive on the cement... the construction will bring in a week and the adhesive will be exposed for several months until the floor is ready to be put down... is it safe to allow children to use classrooms with the adhesive exposed.

Cutback adhesive from that era has a high probability of containing asbestos, but it needs to be tested.

I certainly would not allow children to walk or play on a floor like that. Allowing children on that floor would be a sure case of someone bringing a suit in court, especially if there was no testing.

The grow up members of your church need to re-think this.

Jaz