New to CSC

[Fishnutz]

How does this stringer system compare to the 5 stringer system? I have looked through numerous posts and people usually just laminate ply to the tops to get the desired height, any ideas on how to raise this about two inches? Is there any wood in the large stringers? I was thinking about building a mold on each side of the existing stringer and then filling with a pour in expanding foam. After the cure, trim the top of the foam level and tie the floor to the old stringer and then right over the top down to the floor. Any suggestions?