Modular flooring assemblies

A component of a flooring system comprising

• a flooring component,
• an adhesive,
• a tray substrate having
• a tray substrate surface which is an upward facing horizontal surface,
• a tray substrate bottom with a padding attached to the tray substrate bottom,
• a plurality of tray substrate vertical tray edges which protrude upward and extend around a perimeter of the tray substrate surface
• a plurality of tray substrate edges defining an outside perimeter of the tray substrate,
• the tray substrate edges having a plurality of upward tabs and downward tabs with the upward tabs and the downward tabs extending alternatively from the plurality of the tray substrate edges,
• wherein the upward tabs each have a convex surface and a valley, and the downward tabs each have a concave surface and a lip,
• wherein the flooring component is smaller than a tray surface defined by the tray substrate vertical edges and said flooring component is adhered to the tray substrate surface with the adhesive, further comprising a plurality of grout holders each having an angled shape that widens towards the bottom of the tray substrate, with the grout holders located between the altering upward tabs and downward tabs.