I took up the three layers of floor covering I have in the kitchen only to find a layer of what looks like tar on the sub-floor.

This may be glue that held the first covering down.

Problem is that I cannot remove this tar like substance.

I am afraid that the radiant heating will cause noxious fumes if installed over this stuff.

This is a ceiling to floor do-over; four years in the making and now we are at a stand still. Any one have any ideas or have the same experience?

In appreciation, Meri