Trying to add Materials to Interior

As some of my feedback stated, I needed focus on the texture and material within my design. Describing this more through my drawings. Convey the atmosphere that is created. What is the texture and material on the walls. If it is wooden plywood walls, show draw this on my renders.

I have decided to go back to my sketch-up model and continuing on the idea that I want my float to be comprised of laser cut plywood cuts stuck together, and trying to relate it back to the river that it is floating on, I have created forms that emulate 'splashes' to occupy the interior walls. Once I had made this however, they could be interpreted as paint splashes further conveying a street aesthetic. So I suppose this could be a matter of an individual's perception. 

Adding materials in sketch-up:

I have then rendered these with materials and added entourage / lighting to try and create atmosphere. Because I have only had overnight to remodel this, render it and then add entourage, unfortunately my renders aren't as crisp as I would have liked..