Pebble-Flex® Product Specifications

Product: PebbleFlex® surfacing system for playgrounds.


Top Layer

PebbleFlex two-component aromatic polyurethane primer, PebbleFlex aliphatic thermoplastic polyurethane pebbles, PebbleFlex two-component aliphatic polyurethane Binder. PebbleFlex clear two-part aliphatic polyurethane grout in high-wear areas.

The colors shall be as selected from the drawings, submitted as samples, and mixed on site to the ratios in the samples. Black material, if included, must be an aliphatic thermoplastic polyurethane pebble and not a rubber such as EPDM or TPV.

Impact Layer

The impact layer is to be made of foam and rubber. The foam material shall be 100 percent recycled cross-linked closed cell polyethylene foam that is heat sealed together. The rubber is to be select SBR rubber strands of not more than 1 inch in length.

Equal Materials: The PebbleFlex pebbles are an aliphatic thermoplastic polyurethane pebble. The system is 100 percent color throughout. The two-part PebbleFlex binder is 100 percent solid aliphatic. Any equal product must be urethane based, not rubber based such as EPDM or TPV, must include an aliphatic polyurethane binder and must be 100 percent color throughout. Any black rubber recycled material is not considered equal.

Finish Texture: Pebble grain.

Color: Selected from manufacturer’s color chart by owner prior to bid.

Surface Preparation

New or Existing Concrete: New concrete must be light broom finish and at least 28 days old, and can be prepared simply by acid etching. Add acid slowly to water in clean polyethylene buckets at a ratio of eight parts water to one part acid. Care should be taken to prevent splashing on workers. Protective clothes such as safety glasses, rubber gloves, boots, etc., should be used. The acid solution should be used on the concrete at a rate of 100 square feet per five gallons of acid solution. Concrete needs to be damp before applying acid. Using a stiff broom, scrub acid solution into the surface where the solution was poured and continue the process to other areas. Never let the concrete dry with acid on it. After five minutes, rinse the concrete with large amounts of clean water to remove all the acid solutions, and then allow the concrete to dry. Old concrete that is contaminated with grease or oil can be cleaned with a power-washer. Use a degreasing agent before power-washing. For concrete where a power-washer cannot be used, a diamond grinder can be used to lightly grind the surface to remove contamination. Concrete shall have a minimum of 1/8″/foot. slope to ensure proper drainage.

Asphalt Preparation: New asphalt must be 15 days old. Broom scrub using a degreaser to remove any surface oils. Power-wash any contaminants off the surface. Allow 24 hours for the surface to dry. PEBBLEFLEX CANNOT BE INSTALLED OVER ASPHALT CURED FOR LESS THAN 15 DAYS.

Compacted Crushed Stone: Minimum depth is 4 inches with the top two inches being a stone dust. Compact the base to 95 percent proctor. Slope the base at 1/8″/foot. to accommodate proper drainage.

Curb Preparation: Cut a 3/8″ x 1″ keyway groove into the existing surrounding curbing. Groove shall be swept clean and be free of all residual residue.


Thickness: The total depth of the surface shall be installed in strict accordance and conformity to the manufacturer’s drawings and these specification requirements. Surface thickness will vary in the impact layer. The thickness of the impact layer will be installed according to the fall height(s) of the play equipment called for. These requirements must be verified in the field prior to starting the installation of the impact layer.

Impact Cushion Layer: The impact layer is to be made of a composite of foam and rubber. The foam material shall be 100 percent recycled cross-linked, closed-cell polyethylene foam that is heat sealed together. The SBR rubber is to be a strand of not more than one inch in length.

The manufacturer’s minimum depth or greater shall be installed as required by the fall height(s) required by the playground equipment that exists or is to be installed and to meet the test results of the finished surface as expressly required within this specification.


The foam panels should be laid out in accordance with the playground design including the appropriate use zone. Cut the foam to fit around the legs of the equipment. Leave a gap of one inch between all the panels during the installation. Over concrete or asphalt, adhere the foam to the sub-base using a thickened polyurethane binder.

SBR buffings bond the SBR to the foam by applying a coat of aromatic polyurethane binder over the entire surface. Be careful not to prime too far if it is hot and humid, otherwise primer will cure before SBR is poured. Apply a minimum of 1-1/8″ SBR buffings over the top of the foam panels creating a consistent and even surface.

For surrounding curbing, prime the vertical surface of the curb using the PebbleFlex primer. Mix two 50-pound bags of SBR buffings with two gallons of aromatic polyurethane binder so that the buffings are covered evenly. Spread the mix and trowel to the appropriate depth immediately after the application of the primer. Against curbing, taper the SBR at a 45-degree angle so that the mixture is no less than one inch lower than the keyway cut in the curbing. Let cure for 24 hours.

Top Layer: The overall thickness shall average 0.375″ and be composed of PebbleFlex material with an aliphatic polyurethane binder supplied by the manufacturer.


Roll or brush PebbleFlex two-part primer mixed with fumed silica onto the surface being sure to liberally cover the entire area. Mix an amount of primer that will be used in less than 30 minutes. If it is warmer, the primer will cure faster, and less material should be mixed. Be careful not to prime too far if it is hot and humid otherwise primer will cure.

PebbleFlex Mixing and Finishing

Mix 100 pounds of PebbleFlex pebbles (50 large/50 small) in a mortar mixer. Pre-mix nine pints of PebbleFlex aliphatic, two-component (five parts A to four parts B) polyurethane binder in an appropriate plastic container with a paddle mixer. Add the premixed nine pints of binder to the dry pebbles in the mortar mixer. Mix thoroughly so that each pebble is covered evenly. Dump the mix onto the primed area and spread it at an average thickness of 0.375″, keeping the surface as level as possible. Hand or power trowel using a solution of soapy water to spray the surface of the trowel. This will allow easier manipulation of the trowel. Let the surface set for 72 hours or until dry to the touch before using.

High Wear Areas: Under all high wear areas, such as under slides and swings, apply a layer of PebbleFlex grout. Mix three parts of PebbleFlex grout A with two parts PebbleFlex grout B and apply using a roller or squeegee. Confine the application of grout to square or rectangular areas using tape applied before the application. Allow 24 hours for the grout to dry.

Large Areas: All areas in excess of 2,000 square feet, or areas that require adjacent color pours due to designs, shall have this work done in strict accordance with the manufacturer’s installation requirements with adjacent poured cap layer surfaces being flush throughout. Large areas or adjacent color patterns can require the poured layer cap to be installed on different days. The installer shall employ proper techniques to ensure that no gaps or separation will occur. All cold joints must be coated with binder prior to the application of the adjacent PebbleFlex layer.


The contractor should clean the job site of excess materials, and, if necessary, backfill any excavation around the perimeter with earth or other appropriate material. The contractor shall instruct the owner’s personnel on proper maintenance and repair of the PebbleFlex surface.