We are putting down decking; a small area of the 12x12 is over an old stoop outside the back door. I’m almost positive that I saw a segment where Tom used glue or building adhesive to fasten the boards to that concrete. I haven’t been able to find anyone with any info. We were unable to remove the stairs and that top piece. We were thinking of using concrete screws to fasten then ends just to hold them in place and come back to remove the boards and reinstall them once we found a way to do it. The area is approx 3-1/2 by 4 foot.