Tilt-up's new face: here's an opportunity to join in this sector's growth.

Concrete block producers are finding a surprising new customer--tilt up construction. These producers are making a new veneer product for tilt-up wall panels. And they are uncovering a huge potential market for architectural products in the process.

Chameleon Cast Wall System of Brookline,

The units are economically produced on standard block equipment. Installation of the veneer fits into the tilt crew's normal procedures using existing workers. The amount of labor required at the jobsite is low, and the installed cost of the system is competitive with other premium finishes for tilt-up construction.

This development is striking to many in the block industry who have labored to find ways to compete with tilt-up. Over the last five years, the National Concrete Masonry Association (NCMA) has studied how to stem the loss of gray block's market share to tilt-up construction. Nonetheless, tilt-up has continued to grow, almost tripling over the last decade to almost 500,000 square feet of walls built per year.

Chameleon is marketing the system to expand awareness among contractors and, ultimately, bring it to other areas of North America. "Chameleon is an idea whose time has come," says Darryl Winegar, general manager of Midwest Block and Brick. "In addition to selling a high-margin product, it also positions us squarely at the top of the food chain of the booming design-build market. Our salespeople are making presentations to top management at firms we had a hard time getting into before. They want to see Chameleon, but they also want to hear about the rest of our line."

Big box growth

Tilt-up's growth began in the "big box" market for warehouses and distribution centers. Historically, the construction method has been well-suited to these large, plain structures. But as the big box market leveled off, tilt-up contractors have sought work in smaller, more architecturally pleasing buildings such as schools, stores, offices, and multi-family residential. To appeal to these markets, they have developed a host of construction methods for buildings with smaller, irregular floor plans. They have also looked for architectural finishes that provide premium, traditional looks which these markets require.

The idea for Chameleon originated with an engineer and a marketing consultant in the block industry who read the NCMA research on how to compete with tilt-up. They reasoned that even if tilt-up took more and more of the building projects, block could offer a range of attractive finishes that traditional tilt methods lacked.

Embedded veneers had been used in cast wall panels since the 1960s, and in the last decade, they've been successful in tilt-up construction. (See sidebar "Thin Masonry Veneers"). But no one had developed a practical way to embed a concrete facing unit. With technical assistance from experts in block production and architecture, Chameleon finalized the design and installation methods. Released just over a year ago, six contractors in North America have installed the system in test panels and large and small projects.

Routine production

Two block producers currently license and manufacture the system: E.P. Henry in Woodbury, N.J., and Midwest Products Group in Jefferson City, Mo. "The product is pretty routine to make," says John Poignard, E.P. Henry's head of operations. "There's no core puller, no special equipment, and there's not much different about the way we run the line. The product is only about 2 inches thick, so we can run up to eight full units at a time. We had a high rate of culls on the split-face at first, but we showed them how to modify the molds, and now the cull rate is about the same as on any of our split products. Cubing is a little different, but it's no big deal."

The basic Chameleon system includes six masonry units: a full stretcher (nominal 8x16 in.), half stretcher (nominal 8x8 in.), a left and right full miter, and a left and right half miter. The miters form corners and jambs for openings. Chameleon also plans to offer other sizes and shapes, based on requests from architects.

The units have a subtle chamfer along the top and side edges. In the final wall, the chamfers create a pronounced shadow line in lieu of a mortar joint. There is no mortar and no pointing of the masonry.

Manufacturers so far have produced units with smooth, split, and sandblast faces. They also plan to produce ground-face units. Virtually any color and finish created on other architectural block can be made on Chameleon units because they are produced by the same methods on the same machinery.

At the jobsite

The tilt crew sets the units face-down on the casting slab at the jobsite. By choosing and arranging their units, they can create anything from a simple block-look wall to complex patterns of color and texture. In fact, many designs that appear to defy gravity and would be impractical with conventional masonry can be made relatively simply.

The masonry no longer has to hold itself up--the cast concrete takes care of that--so units can be turned at odd angles, and openings can have irregular shapes without concern for getting rebar in the block. Designing can become more like creating a mosaic than stacking blocks.

When the units are in place, workers sweep fine sand over their backs. The sand fills the joints between the units to prevent cement paste from bleeding through and fouling the face during the concrete pour. Then the crew snaps plastic "clips" over the dovetails on back of the units to lock them securely into place.

After this, work proceeds as it does in conventional tilt-up. The crew sets the reinforcement and lift inserts in place, and calls for the concrete. Less than an hour before the pour, they mist the backs of the units thoroughly. This wets the masonry so it doesn't suck water out of the concrete mix, and settles the sand firmly into the joints. Mix design, concrete placement, and consolidation are the same as with ordinary tilt-up panels.

Other benefits

There are also some logistic advantages for construction. For one, it is not necessary to cast the panels on a slab. Pennsylvania contractors built about 10,000 square feet of walls for a shopping center on the ground.

"There was no slab available. We leveled the ground and covered it with a couple of inches of pea gravel and set the Chameleon right on the gravel," explains Dave Bohr, project manager at Lithko Contracting Inc. "In fact, we ran heating tubing in the gravel and worked right through freezing weather. We got up to speed pretty quickly and ended up with a cost for adding on the Chameleon of about $5.25 per square foot, including all the materials and labor for installing the veneer."

Even when the panels are cast on a slab, there's no need for a bond breaker because the concrete never contacts the slab. At the lift, there is virtually no suction. Because the finish is created in a controlled manufacturing environment, there are no bug holes and no telegraphing of imperfections in the slab, so the repair work on the finish (what tilt contractors call the "sack-and-patch") is minimal. Occasional small spots of bleed-through can be removed with a wire brush or masonry cleaner.

Meyer Brothers Building Co., a respected design-build firm, used Chameleon panels to create a decorative archway for its new headquarters building in Lees Summit, Mo., just outside Kansas City. "Our crew took to the work quickly," says Mark Meyer, construction division president. "Installing the Chameleon facing created minimal disruption to our normal panel construction. The walls looked great after little more than an ordinary power wash. The crew is confident they can efficiently build high-quality panels by themselves in the future."

The author formerly researched and designed new construction products as a professor at Boston University. He is an ACI-certified tilt-up technician, and holds a Ph.D. from the Massachusetts Institute of Technology. He is director of market development for Chameleon Cast Wall System. Telephone 617-232-3354 or visit www.chameleonwall.com.

Construction Spec Available

Chameleon Cast Wall System has released a formal construction specification for Chameleon tilt-up wall panels. The specification is designed to be fully compatible with the Concrete Specifications Institute's MasterSpec format. This will ease the task of incorporating Chameleon into formal construction documents and give designers and specifiers confidence that the critical instructions for assuring quality installation are thorough and correct.

Chameleon is developing tools needed by project designers and specifiers as the system is bid and specified in more complex, value-added building projects. A copy of the specification is available in Word or PDF format from regional Chameleon suppliers or from Chameleon Cast Wall System.

Thin Masonry Veneers

Precast wall panels have incorporated embedded thin brick since the 1960s. Plant workers pressed the bricks into rectangular depressions in an elastomeric form liner, cast concrete on top, and later pulled off the liner. The method faithfully reproduced the look of a brick facade, complete with a faux mortar joint made of the concrete running between the bricks. But the $25-per-square-foot form liner was much too expensive for tilt construction, where generally it could only be used once.

Entrepreneurs in the mid-1990s created inexpensive plastic "single-use" form liners that were capable of holding thin brick. These filled the bill nicely for tilt-up, and in the last few years their use has exploded. Sales estimates are in the millions of square feet of materials per year, and growing 30-50% annually. Every year, many of the Tilt-Up Concrete Association's awards go to buildings that incorporate thin brick. Contractors now can choose either Innovative Brick System's MBrick product, or Scott Systems' Brick Snaps.

Another thin block product named BlockSnaps, sold by new firm UpKon, is coming to market. It also employs a single-use liner product to hold the units and create a faux mortar joint.

For more information, contact Innovative Brick Systems at 800-413-4588 or www.mbrick.com, Scott System Inc. at 303-373-2500 or www.scottsystem or UpKon at 920-734-7020 or e-mail global.net.

Brick travels 9800 miles

Building the parking garage at Abington Memorial Hospital in Abington, Pa., was an especially challenging project because the new seven-level, 900-car structure had to match the hospital's existing nearby buildings.

Architect Robert M.R. Mainwaring, vice president with Robert D. Lynn Associates in Philadelphia, met the challenge by going half a world away for the right product. Ironspot is a deep reddish-gray thin brick resembling iron he found 9800 miles away in Australia. Each one weighs only 1/6 the weight of a typical brick.

Nitterhouse Concrete Products, a precaster based in Chambersburg, Pa., used Scott System's Brick Snap Inlay System to cast the thin bricks into panels and columns. The panels were produced by placing the plastic templates into the forms and then placing the thin brick facedown into the templates. Concrete was then poured over the back of the brick assembly, vibrated, and finished. The brick-faced spandrel panels, columns, and stair panels were then lightly sandblasted.

"Involving the precaster during the design development stage enabled our staff to analyze the various finish options available and to choose the one that achieved the warm, rich, iron-colored brick finish we were hoping to attain without sacrificing the owner's budget or slowing down the construction process onsite," says Mainwaring. Precast concrete was the only material he considered for the project.

Brick and Glass Products

The following manufacturers offer the look of brick at only a fraction of the weight and cost. One other offers recycled glass for decorative concrete.

Brick facade for unmatched creativity

The BRICK SNAP system by Scott System Inc. can create brick facades in tit-up, precast, and poured-in-place concrete. Available in six sizes and a myriad of colors and textures, BRICK SNAP allows designers and specifiers unmatched creativity and flexibility with brick-embedded concrete. The brick is packaged face down into individual plastic templates that snap together on the pour surface. Concrete is then poured over the assembly, vibrated, and finished in the normal manner. The panel is lifted, the templates removed, and a beautiful brick facade is complete. Use for medical and residential buildings, schools, stores, parking structures, and sound and retaining walls. Scott System Inc. www.scottsystem.com. 303-373-2500. Circle 6.

WOC booth #N964

Clay units come in many colors

Architectural Metrobrick is designed with a channel back and strict size tolerances for superior installation and bond performance. The product by Ironrock is a thin fired clay unit used as a wall covering and providing the appearance of conventional brick masonry. It can be used either thin-set or morter-set in the field using traditional the setting and grouting methods or various types of panel systems. The product is available in a wide variety of through-the-body earth tones. Ironrock. www.metrothinbrick.com. 888-325-3945. Circle 7.

Glass for decorative concrete

American Specialty Glass offers 25 vibrant colors of recycled glass from around the United States. The glass is cleaned and processed into nine standard sizes, ranging from 4 inches in diameter to a fine sand. The manufacturer finds white sand, made from clear glass, is an excellent substitute for silica sand. Fines make an ideal permanent coloring and texturing agent for decorative concrete. Glass is packaged in 1-, 5-, 10-, 25-, and 50-pound clear bags, and 3000-pound super sacks. Glass chips also may be used with portland cement-based applications. Use in precast panels, tilt-up, and concrete countertops. American Specialty Glass. www.american speciltyglass.com. 801-886-1636. Circle 8.

WOC booth #S11347

Brick-face concrete panels have several applications

To enhance in-place installation, Endicott Tile's thin brick features a distinct keyback design which provides a mechanical lock into the concrete for maximum durability and permanence. This design also results in increase shear values and pull-out strengths. The product is available in 16 colors, three sizes, and six textures--sand finish, smooth, velour, sand heritage, smooth glazed, and wirecut. Applications for brick-faced concrete panels include parking ramps and structures, warehouses, and office buildings and public facilities such as fire stations, park structures, and noise barrier walls. Endicott Tile. www.endicott.com. 402-729-3323. Circle 9.