Anyone know what this is?

What is this wood banner across the floor? It’s hollow when I knock on it and worried about removing it? I think the pipes may be running across it? Anyone have something similar?

I’m thinking of removing it, and plastering it to get a clean finish around the stairs. Anyone have any suggestions?

What is this wood banner across the floor? It’s hollow when I knock on it and worried about removing it? I think the pipes may be running across it? Anyone have something similar?

I’m thinking of removing it, and plastering it to get a clean finish around the stairs. Anyone have any suggestions?