A Longitudinal Study of Playground Surfaces to Evaluate Accessibility - Final Report

Tiles

There were two sites surfaced completely with tiles (TIL), while eight additional sites were combined with engineered wood fiber (EWF).  The 2 ft. x 2 ft. bonded rubber interlocking sections are marketed as easier to install and more flexible should they need to be reconfigured to accommodate new playground equipment. The cost for TIL ranged from $8.96/sq. ft. to $21/sq. ft.  TIL was the most expensive of the five types of surfaces identified for study.  This can be attributed to the number of small surface area installations where the use of TIL was less than 2,000 sq. ft.  These installations limited the use of the TIL to connect the accessible route from the playground perimeter to the transfer system of the elevated composite structure.  The remainder of the larger play area was surfaced with a loose fill material. 

For one agency which manages more than 50 playgrounds, their selection of TIL was based on the agency’s perceptions that installation by its own personnel would help to drive down the overall cost of the playground project, stretching more dollars when budgets are tight.  They also believed that the TIL would create an accessible route with less maintenance requirements than the EWF predominately used on their other playgrounds.  During the initial site visits, the TIL had started to shift on at least two playgrounds where the parks maintenance staff had installed the surface system as opposed to installation by a contractor certified by the manufacturer.  The playground owner attributed the construction error to the learning curve involved with installation of the new surface and reported each new site was improved based on the experience maintenance staff was gaining.  The agency’s third playground with TIL was bordered by a landscaped paver retaining wall.  Improper drainage from the landscape in the retaining wall was causing a build-up of silt on and under the tiles.  Within the first month of installation, at least a dozen tiles at the border were pulled up to remove the silt build-up, the section was thoroughly cleaned, dried and the TIL were re-adhered to the concrete sub-base.  Maintenance staff was on site making the repairs when the accessibility assessment was conducted.  The assessment team brought another area to their attention where the four tiles bordering the concrete walk at the entry to the playground were raised more than a quarter of an inch and adversely affecting the accessible route into the play area.  Maintenance staff was able to remove the four tiles, shave the underside and re-install so that they were flush level with the concrete walk all while the assessment team was concluding the field testing. 

As noted in Table 3, the Mean SDS for TILs continued to increase each year of the study.  The mean for the firmness and stability of the tiles tested in the sample was also under .50 inches, similar to the PIP.  Throughout the period of the study, there were reoccurring instances where the TIL were assessed with punctures holes ranging from .50 inches to more than 2 inches in diameter and where the seams had started to shift or buckle creating openings and changes in level along the accessible route.  It was unclear whether the puncture holes were products of intentional vandalism or unintentional damage from users stepping on rocks and other foreign objects with enough force to penetrate the surface.  One playground owner went so far as to install signage at a site “No high heels” with the image of a woman’s shoe.  The maintenance staff was also able to replace the TIL with puncture holes following the site assessments.

Deficiencies were identified at two playground sites surfaced with a combination TIL and EWF.  The intent of the playground design was to use the TIL as the primary accessible route to points of aggress/egress and fill the remaining use zone with EWF.  The loose fill particles of EWF were scattered throughout the play area, across the tiles, concrete walkway and in the grass.  Some of the particles had started to lodge in the TIL seams causing separation at the seams.  There were even instances where the particles had lodged so deep in the seams that the adhesive had degraded and the TIL had separated from the concrete subsurface.

During Years 3‒5, locations were identified where the TIL had cracked in the center unable to support repeated weighted foot traffic.  These instances occurred where either the subsurface or structural integrity of the surface product was compromised.