I removed my carpet and found these things. What are these black rubber patches?






Are they for sound? I cleaned the floor with vinegar and these things absorbed it. I didn’t hurt anything did I?

 

Sorry this thread got ignored. yeah, it's sound deadening material. No clue if vinegar hurts it, but if degradation becomes an issue you can replace that stuff with aftermarket sound deadening mats or whatever you decide is best

 

Just curious, did you remove your carpet just to clean underneath or are you replacing the old carpeting. If you are replacing where did you purchase replacement carpet ?