When Orange County's Colonial High School was constructed in the 1950s, Orlando was a mid-sized, central Florida town — not the world-renowned resort and vacation mecca known today. Over a period of nearly five decades, more than two dozen separate additions, annexes and outbuildings were appended to the original three-story structure or built on campus to meet the facility requirements of a ninth through twelfth grade student population numbering just over 3,400 pupils in 2002.

By the late 1990s, Orange County School District officials realized the property was in desperate need of repair and upgrade. A 1998 facility assessment documented the compromised condition of the campus, leading to approval the following year of a plan to remove, rebuild and repair the Colonial High School compound to create a progressive, state-of-the-art learning environment.

The campus was master planned and designed by BRPH Architects/Engineers, Inc. of Melbourne, Fla. Architect of Record Michael Karaffa, AIA, currently of Palm Bay, Fla.-based Don Facciobene, Inc., reports that the initial aim for Colonial High was to create an attractive campus setting with construction materials that would withstand the daily punishment of thousands of teenagers. “Water repellency was a primary issue, as we needed buildings that would survive the humid and wet Central Florida climate, prove efficient to operate, and remain attractive for the long-term,” he notes. “But just as important was total construction cost. Obviously, we were working under some very tight budget constraints and needed to find the best performing, most economical system.”

Karaffa originally specified a double-wythe wall system of 8- ∞ 8- ∞ 16-in. masonry units with a 4-in., split-face block veneer, but financial considerations rendered this design untenable. When Orange Country representatives proposed a concrete masonry and stucco system, the architect objected because of the high risk of water infiltration and ongoing maintenance required. He then learned about the Control-Blok System, whose proprietary design prevents water and wind-driven rain from reaching the interior surface of concrete masonry walls.

Designed specifically to address the age-old problem of water leakage that can affect the performance of traditional concrete masonry units, Control-Blok prevents water leakage by means of three mechanisms: (1) a beveled edge that sheds water from the mortar joint area and allows easier access for proper tooling to ensure a watertight interface between the block and the mortar; (2) horizontal web surfaces grooved to prevent water transport; and, (3) the use of Rheomix, Rheopel or Color Cure XD polymeric, integral water-repellent admixtures for concrete block and mortar.

All of the Control-Blok used in the Colonial High construction — 140,000 units in all — was supplied by Anchor Block of Florida, Inc. from its Edgewater plant. Anchor Block Sales Representative Glenn Bullard remarks, “This is a showcase project for the Control-Blok System because we were able to meet all of the owner's and designer's requirements with a cost-effective, architecturally appealing system. The fact that we were able to provide a single-wythe wall system with required moisture protection was the key factor.”

Due to the project size, construction was staged in two phases. The first began in the summer of 2000 with the demolition of seven buildings and construction of seven new structures on the 60-acre site. Nearly 75 temporary modular units were set up to house classes and activities displaced by the demolition. Over the next year, construction progressed full bore on a 49,470-sq.-ft. gymnasium complex; two-story, 54,456-sq.-ft. cafeteria; 825-sq.-ft. mechanical building; two-story, 23,184-sq.-ft. administration building; and two-story, 36,386-sq.-ft. media center.

LEARNING CURVE

Orlando-based Skanska USA Building, with joint-venture partner SL Construction & Remodeling of Gainesville, Fla., has served as construction manager for Colonial High. Skanska USA Project Manager Jason Morgan, who has overseen the construction, cites the benefits of Control-Blok for this type of building: “In addition to durability and aesthetics, the masonry units offered us the benefit of accelerating our construction schedule. Compared to split-face double-wythe wall construction, this [system] is much faster. There's a learning curve for the masonry contractor because an engineered, single-wythe wall system must be installed correctly to be effective. There is a top, bottom, left and right to the blocks, so installation is a bit more time-consuming than that for regular concrete masonry units. But, in the end, it is significantly faster than double-wythe wall construction; plus, it is architecturally pleasing and requires no secondary finishing for appearance. The Control-Blok units used on this project were manufactured as lightweight block so they achieved a three-hour fire rating, and that was a major benefit.”

The Phase One buildings were opened to students and faculty following the winter break of 2001, and construction began on the final two new structures: a two-story, 136,608-sq.-ft. main classroom building and a 17,992-sq.-ft. art center. At the same time, renovation of an existing performing arts center, band building, agricultural building, auto shop and ESE (exceptional student education) facility proceeded.

All of the new construction utilized reinforced concrete masonry units with poured concrete beams and floor slabs. Supplementing the inherent water-repellency of the Control-Blok System and the water-repellent admixture used in the masonry mortar is a new PVC flashing system, which ensures that any water entering the wall is collected on an embedded pan positioned over the cores. As the water collects in the pan, it is diverted to the wall exterior through weep spouts. This simple flashing provides 51 percent bonding capacity, compared to the 4 percent that is traditionally achieved with conventional through-the-wall flashing systems.

TRUE TO THE SCHOOL

In view of Colonial High's colors of red and black, the Control-Block was specified in Saffron (red) for lower levels and Wheat for upper levels. In the overall design, the two colors of Control-Blok are combined with panels of gray masonry and poured concrete tie beams finished in Wheat-colored stucco.

BBA MCI of Clarksville, Ind., was the job's primary masonry contractor. Due to the amount of masonry used on the project, BBA had up to 75 masons and 95 laborers during peak periods working full time for a total of nine months over the two phases. “The schedule on this project was aggressive. During peak construction, we were able to install between 4,000 and 6,000 units per day,” explains BBA President Vic Beeler, Sr. “There is an educational element to the Control Block System — you need to train your masons on the nuances of the block design and installation. But, due to the beveled-edge design, tooling of the joints is easier, and you don't need to seal the joints after installation because of the integrity of the water-repellent mortar mix.”

Vic Beeler, Jr., BBA's project manager, was likewise impressed with Control-Blok. “It's an architectural product that is much better looking than standard split-face block and a value-added material that allows you to do something a step above what has been offered traditionally,” he affirms. “Furthermore, our rough estimates indicate that the system priced out at $700,000 or more in savings compared to a double-wythe, cavity wall alternative because of labor savings with a single-wythe system and elimination of the cavity material and block veneer.”

According to Anchor Block of Florida's Glenn Bullard, Colonial High School is a showcase project because it illustrates the versatility and water-repellency of concrete masonry construction and the specific benefits of Control-Blok. “This is a very attractive, highly functional and extremely cost-competitive project because of the wall system. The colors, the texture, the radius turns on several of the buildings all combine to add to the depth and interest of the campus,” he explains “But the real value in this product is in the water-repellency. Water-repellent admixtures used in the block mix design reduce the potential for efflorescence and eliminate the potential for mold growth, which is a very real concern in our marketplace.”

Construction on the $49 million Colonial High School project is in the final stages, with interior finishing work underway on the last two newly constructed buildings (the main classroom building and the art center) and grading and landscaping of an exterior courtyard area that serves as the nucleus of the campus. Skanska USA Building's Jason Morgan notes that the project is on target for completion slightly ahead of schedule in March of 2003.
— Report provided by Master Builders Inc.

COLONIAL HIGH SCHOOL

PROJECT PRINCIPALS

Block Producer
Anchor Block of Florida, Edgewater, Florida

Designer/Engineer
BRPH Architects, Melbourne, Florida

Project/Construction Manager Skanska USA Building, Orlando, Florida

Masonry Contractor
BBA MCI, Clarksville, Indiana

CONTROL-BLOK

A patented design of Newblock Corp. in Bell River, Ontario, Control-Blok is jointly licensed to concrete producers by Cleveland-based Master Builders, Inc., manufacturer of Rheomix Rheopel and Color Cure water-repellent admixtures for concrete masonry.