Thanks for the info. It wasn't a tile floor. From what I understand it was a big roll that was cut to fit the floor. I'd read somewhere that Armstrong Solarian flooring with asbestos was still being laid on floors until the mid 90s. I'm not sure what held everything down then since I don't see any nails or tacking. The tarpaper was probably an old roll that they had around and used it to place under the vinyl flooring. How dangerous would it be to remove tarpaper with asbestos from a board? Then I wouldn't have to worry about ripping vinyl flooring; I'd just have to rip the tarpaper up and hope the flooring comes with it.

From the information given, there would be next to zero chance of asbestos in the air. Unless you are sanding (not advised anyway) there is no way for you to breathe in dust.

Good to know because I've been panicking for days.

Tar paper (flooring underlayment) was usually adhered with a hard setting linoleum paste. If you look very closely, you may see this brown material between the plywood and tar paper layer. Typically, Armstrong Designer Solarian was not adhered to loose layed tar paper.

You had no exposure to asbestos, other than what is typically found in a litre of air in your region.

Thank you for your answer. It's an old house, so it is hard to tell what else I am being exposed to here. The more the think about it, the more I'm not sure if it was tar paper. It was a thick sheet of something. I actually reminded me of old roofing shingles. It may have even been thicker than the solarian. What kind of paper would this be?

Without examining a sample, no way of telling. Could have been 30 lb. Roofing felt or the existing Solarian was installed over an existing sheet flooring, which could have had an asphalt saturated backing. Whatever the case...you're good.

Thank you!

Not to be snarky, but if you're at all in doubt, do a search here on this subject. This issue comes along fairly often and the answers are always consistent.

After minimal and limited exposure to asbestos, the fibers are generally removed from the body by your mucous membranes, just like any other particulate that is inhaled. I agree with all of the other sentiments recorded above. You need not worry.

Installing a layer of plywood over your entry floor isn't likely to release any harmful fibers.