Tumbled Talk

By Jolynn Bennett, Pavestone Company

Tumbled pavers require at least one of two products: one, polymeric sand, either pedestrian grade, or vehicular grade; or, two, sand joint stabilizing paver sealer. It's difficult to seal a freshly installed paver project because of the danger of trapping efflorescence, especially when using non breathable sealers. Photos: Pavestone Company

Who could predict that the antiqued, time-worn, distressed look of tumbled hardscape materials would be as popular today as the simple, smooth-faced rectangular paver in the early days of the concrete paver industry? The sharp edges and corners of various paver shapes can be beautifully processed to resemble the texture and appearance of ancient cobblestones.

Many of today's architectural styles call out for such a finishing touch. Walkways, patios, driveways, pool decks, plazas, grand entrances and streets laid with tumbled pavers can look as if they have gracefully survived decades of use.

Modern style vs. old world, smooth vs. textured, crisp-edged vs. weathered, the pull is toward a more natural stone-like appearance, reflecting a desire for a classic sense of permanence and elegance. Rumbling around in a mixer on the job site or through the manufacturer's secondary processes used today, the rustic finished paver retains the benefits of its more pristine predecessor: ease of installation, durability, flexibility, all in a variety of shapes and pattern combinations.

C-33 concrete sand must be used with tumbled pavers as the tumbling process eases the edges on both the top and bottom of the paver, so the aggregate size is imperative for maximum lock up from the bottom of the paver upward after the compaction process.

History: A Chip off the Old Block

Tom Davis, General Manager of the Pavestone Company plant in Grapevine, Texas comments, ''I don't know of a single contractor who tumbles his own pavers in a mixer or other similar apparatus any more. It is much less expensive to order the product already tumbled from a manufacturer.''

Tumbling Process Today

Davis continues, ''Mostly automated drum or in-line tumbling equipment lowers the per-unit process cost substantially, but you have to have enough unit quantities to keep the fixed costs (on the capital expenditure for the equipment) low. The price of automated tumbling equipment is high enough that it is not economically typically viable for most contractors.''

In the past, landscape contractors and paver installers employed the old and very slow mixer process to chip off the hard edges of concrete pavers for the softer appearance requested by customers. The result was high labor cost per unit.

Installation Tips

Contractor Charles Graves, Decorative Paving Systems of Forney, Texas, counts tumbled paver projects as a majority of his business. His customers prefer the more natural, softer look that the tumbling process produces.

Miller adds, ''We generally use polymeric sand 99 percent of the time, and educate and persuade the client to apply the sealer 90 days after the installation to insure the paver is fully cured. This way good Ol' Mother Nature has a chance to wrap up the final naked appearance of the project, as she naturally weathers the project with rain and decomposing organic materials that help fill any remaining crevices.''

There are multiple shapes and sizes of tumbled product to meet a vast array of architectural themes. In most cases, any concrete paver can be tumbled provided its overall shape is not too large. Size of tumbled product is relevant as most current tumbling processes may incur excessive broken corners on larger units. This is dependent on the tumbling process and is specific to the level of tumbling technology utilized.

Design Considerations

Tumbled pavers blend harmoniously into most residential or commercial settings and complement the equally strong current trend toward natural surfaces in segmental retaining wall products. Although developed for use in standard concrete paver applications, there are some considerations to acknowledge when designing a project with tumbled pavers.

Richard Bodie, Vice President of Commercial Sales for Pavestone Company notes that the durability of tumbled pavers has not been questioned in the paver industry for the past decade. ''Tumbling technology has been in practice Europe for many years prior. Creating the distressed corners and edges is accomplished thru various in line and off line production techniques. The end appearance invokes tradition and character to the paved paver surface. A key component to quality of the tumbled product is that it has been cured adequately prior to the tumbling process. Manufacturers understand this requirement and allow for the material to be sufficiently hardened. Being familiar with your local producer and capabilities will insure satisfaction from the design professional to the end user.''

The Value of Patina

As those of us who frequently watch PBS television's Antiques Roadshow have been taught, real or simulated patina is a valued asset?EUR??,,??character. Patina is defined as a change in an object's surface from natural aging, wear, and exposure. The beauty of age, the mellowness that comes with years of usage, is a welcome contrast to the slick, high tech world we live in today. With tumbled hardscape products, contractors, homeowners and landscape designers can give a comfortable nod to the past without sacrificing quality and durability.