How to hang floating shelves on shiplap?


I put up shiplap in a small nook area. I attached the shiplap to furring strips because I did not want to damage the walls. The problem I am having now is that the holes I drilled are too deep and the screws I had for the shelf anchor I am using are not long enough. I also don't know if I got a stud or not because of the depth of the shiplap against the wall. What can I use to make sure I can get the screw into the wall? Do I need a longer screw? I will also prob need anchors to fit to secure the shelves.

The furring strips are .75"H x 1.5"W x 8ft L

The shiplap is .5625"H x 5.25" depth x 8 ft wide

The mounting screws I purchased are these

q how to hang floating shelves on shiplap
  17 answers
Your comment...