We just took up 50 year old vinyl tile off of our basement concrete floor. Under the tile was a black glue/adhesive that won't come off. We even used a commercial strength adhesive remover but it didn't help at all. We have scraped it until the floor is smooth but we didn't know if we needed to take the adhesive completely up.
We are wanting to paint the flooring with waterproofing paint/sealant. Then we will be tiling the flooring.
So our question is do we have to completely take up the adhesive? And after we "paint" the floor with the waterproofer then can we just grout over it and tile?
Also it is a basement floor but the house is almost 70 years old and does not have any settling cracks. So do we need a tile membrane to prevent the tiles from shifting and cracking?
Thanks so much for your help. We just want to do this correct the first time so we don't have to redo it.