Structural underlayment support system and panel for use with paving and flooring elements
A paving system for paving or flooring includes a top layer of a plurality of paving elements, and an underlayment support layer of a polymeric material configured into panels. The panels are suitable to support the paving elements, the panels having a generally planar support surface.
1. An underlayment support panel for supporting a plurality of paving elements, the underlayment support panel having a core, a top side, and a bottom side, the panel being made from one of an expanded polypropylene bead material or an expanded polyethylene bead material and configured as a water impervious layer of the paving system, the core defining a recovery characteristic such that a deformation from a concentrated compressive load applied for a short duration onto the top side returns the top side to a generally planar condition, the core further defining a first thickness, at least one of the top side and the bottom side including a plurality of projections, the projections having a height extending from the core and defining a second thickness, wherein the ratio of the second thickness to the first thickness is in a range of 5 percent to 25 percent.
2. The underlayment support panel of claim 1 wherein the plurality of projections are spaced apart to define drainage channels having a width that in conjunction with the projection height provides water drainage from a first edge of the panel to a second edge of the panel.
3. The underlayment support panel of claim 2 wherein the drainage channels intersect with a plurality of drainage holes that extend through the panel core.
4. The underlayment support panel of claim 3 wherein the other of the top side and the bottom side include projections that define water drainage channels, and wherein the drainage holes intersect the top side drainage channels and the bottom side drainage channels.
5. The underlayment panel of claim 2 wherein one of the first and second panel edges defines an interlocking structure with an edge of an adjacent panel that is configured to be assembled with the underlayment panel to form a layer where the interlocking structure resists movement in one of a plane parallel to the top side or a plane perpendicular to the top side.
6. The underlayment panel of claim 2 wherein one of the first and second panel edges is configured to abut an adjacent panel configured similarly to the underlayment panel in a spaced apart relationship to provide fluid communication between the top side and the bottom side.
7. The underlayment panel of claim 5 wherein the one of the first and second panel edge interlocking structures is one of a dovetail projection, a dovetail recess, an overlapping hook portion, or an overlapping flange that mates with a complementary interlocking structure of the adjacent panel.
8. The underlayment panel of claim 7 wherein at least one of the first and second panel edges includes at least one projection that abuts a portion of the adjacent panel edge to provide a space between the adjacent panels capable of accommodating at least one of thermal expansion and water flow.