News Center Home > Flooring > Case Study 4 Penn Plaza (Office renovation) LOCATION Philadelphia, PA PRODUCT LEVELROCK Brand FLoor Underlayment 3500 PROJECT OWNER Leggatt McCall Properties, Inc. GENERAL CONTRACTOR Intech LEVELROCK APPLICATOR Pyramid Finish Cement, Inc. "The LEVELROCK gypsum underlayment bid turned out to be less than half the cost of the self-leveling concrete bids." Steve DeGaray President Pyramid Finish Cement, Inc. NOTE: This page is formatted to print out as a USG LEVELROCK Brand Floor Underlayment Case Study. The print format differs slightly from Web page format. LEVELROCK® Brand Floor Underlayment Delivers Major Cost Savings for Philadelphia High-Rise Philadelphia's 4 Penn Plaza was originally built in the 1960s. The use of LEVELROCK® Brand Floor Underlayment 3500 cut floor underlayment installation costs in half compared to using self-leveling cement during the recent $70 million renovation of the 20-story 4 Penn Plaza office building in downtown Philadelphia. The project required application of approximately 525,000 sq. ft. of underlayment over existing concrete floors inside the 40-year-old, building. Application of the underlayment was handled by Pyramid Finish Cement, Inc., a subsidiary of New York-based Pyramid Floor Coverings, Inc., one of the leading flooring subcontractors in the eastern U.S. "We bid the job two ways," said Steve DeGaray, president of Pyramid Finish Cement. "One bid was to cover the floors with a concrete self-leveler. The general contractor received bids from other contractors, also proposing concrete products. "But it was our second bid that enabled us the get the job," DeGaray continued. "We proposed using LEVELROCK 3500 underlayment and that bid turned out to be less than half the cost of the self-leveling concrete bids." Approximately 525,000 sq. ft. of LEVELROCK 3500 underlayment were applied throughout the 20-story building. LEVELROCK Brand Floor Underlayment 3500 offers compressive strengths up to 4,000 psi and is ideal as a topping application over uneven existing concrete. It can be applied as thin as 3/8-inch thick and up to 4 inches thick. It stands up exceptionally well under heavy-traffic use. As evidenced on the 4 Penn Plaza project, the product also dramatically reduces surface preparation time in comparison to portland cement products. The existing concrete floors at 4 Penn Plaza, prior to underlayment application. Same floor, covered with freshly poured LEVELROCK underlayment. The LEVELROCK underlayment dries quickly leaving a smooth, high-strength surface. "To apply a cement self-leveler over this surface involves use of a 'shot-blaster' to peel away the top layer," said DeGaray. "Then you need to clean and prime the floors. It's a labor intensive process, but it's the only way to ensure a good bond. Using LEVELROCK underlayment, on the other hand, requires only light surface cleaning and priming. And there are no questions about the integrity of the bond." The LEVELROCK underlayment was poured 3/8-inch thick over the concrete floors on all 20 stories. USG supplied pre-blended 60-pound bags of product for the job. The blend consisted of pre-determined ratios of sand and LEVELROCK underlayment compound. Pyramid Finish Cement crews simply added water to the pre-blend (using a computerized flow meter to ensure consistency), primed the surface and poured the gypsum cement. "The pre-blended bags helped reduce our installation time and ensured a very consistent mix … for a very reliable floor," said DeGaray. Pyramid Finish competed the project on-time and on-budget. The redevelopment of 4 Penn Plaza will bring 525,000 sq. ft. of Class A office space to Philadelphia's City Center district.