Webster University “Green Roof”

Western Helps Webster University Grow “Green”

The home campus of global educator Webster University is in picturesque Webster Groves in suburban St. Louis. Encompassed in the university’s worldview and course offerings is a strong sense of environmental awareness. Which made this past April’s Sustainability Conference held in the new East Academic Hall a milestone occasion.

This LEED Silver Candidate structure is three stories and 92,000 square feet of learning opportunities. And on its roof is still another: the lushly vegetated system installed by Western’s St. Louis branch.

The overall roof design called for two green sectors and a third traditional surface. Each of the green areas received a base layer of fully adhered TPO membrane, to which some 1,600 vegetation trays—each 24-by-24 inches—were secured. The remaining roof system included fully-adhered TPO membrane adhered to tapered insulation.

Dealing with live material added to the complexity, confirms project manager Thom Belgeri. “The vegetation trays had to be ordered months in advance, and we had to coordinate our work with that of multiple trades. It was definitely challenging.”

To meet the University’s tight deadlines and aesthetic expectations, Western representatives took part in regular owner’s meetings with the general contractor and architects.

“Our client was most pleased with the results,” Belgeri notes. “And we’re very excited to have contributed to such a high-profile example of sustainability.”

A total of 1,600 vegetation trays, each two-foot square, were secured to the two green sectors to create the lushly landscaped roof. Fully adhered TPO membrane was applied to the entire roof, with tapered insulation affixed to the non-green sector.

African Forest Exhibit at the Houston Zoo

The Houston Zoo located on 55 acres in Herman Park began operations in 1922. It is a home to 4,500 animals representing 900 species. It welcomes 1.6 million visitors every year.

The zoo has expanded several times over the years. The most recent addition is the African Forest phase one, which opened in December, 2010. It covers 6.5 wooded acres and features chimps, rhinos, and giraffes. The African Forest allows visitors to explore and learn in different ways – through traditional signage, interactive elements, and dynamic personal encounters.

Western Specialty Contractors had the opportunity to complete the waterproofing portion of the new construction project for the general contractor, Gilbane Building Company. Western’s work items included:

  • The application of below grade and above grade waterproofing.
  • Installation of sheet good waterproofing membrane and joint sealants.
  • The application of clear water repellents.

Des Moines Art Center

The Des Moines Art Center is an art museum with an extensive collection of painting, sculpture, modern art and mixed media. Over the past 60 years the Art Center has seen substantial growth. As the museum’s popularity increased, the number of long-term art exhibits and sculptures grew, also requiring additional storage space.

It was critical that the new addition did not distract from the architectural characteristics of the building. By placing the storage underground in a hill, it would be easily accessible from an existing driveway, but still remain out of sight. An unobtrusive addition was consistent with the original design for a museum that hugs the hilltop and merges with the neighboring Greenwood Park surroundings.

The design called for a sod grass rooftop. The roof was sloped for easy access providing a place where people could walk and use without knowing it was a roof. The space could accommodate outdoor gatherings of up to 450 people.

Western Specialty Contractors was awarded the contract to install an American Hydrotech – Garden Roof Assembly. A hot-applied waterproofing membrane was applied to the horizontal concrete deck surface, as well as the exterior of the new cast-in-place concrete walls. Work began on the vertical walls (approximately 6,000 square feet) in the fall of 2010. Western then returned in the spring of 2011 to install the membrane on the roof deck (approximately 12,000 square feet. The final components to the Garden Roof Assembly were then installed and new sod was laid. The project was completed on time and the area was open in time for a gathering in Fall 2011.

Brockman Hall for Physics at Rice University

Western Specialty Contractors recently completed a new construction waterproofing project at Brockman Hall for Physics, Rice University. The project included slab and wall waterproofing and the waterproofing of the concrete deck below the green roof. Bentonite waterproofing was utilized on the walls and slab and a welded thermoplastic Bentonite membrane on the green roof.

After the slab and walls were waterproofed, work began on the concrete roof lid. A temporary hotapplied membrane was applied and covered with ¾” treated plywood. This created a waterproof working surface over the building during construction. The plywood was then removed and the permanent heat welded thermoplastic membrane applied. EFVM water testing was used to insure the integrity of the waterproofing system.

After the successful water test was completed, the Western crew installed roof barrier, drain mat, protection board, retention fabric, and filter fabric to complete their portion of the project. The landscaping contractor followed with the engineered growing media and planting material. Aggregate walks and a paver system completed the green roof.


Tenochca Hall at San Diego State University

San Diego State University approached Western Specialty Contractors to help solve water intrusion problems at Tenochca Hall. After surveying the building, it was determined that aged sealant at window wet seals, window perimeters, metal to metal joints, and stucco control joints were the issue. These sealants needed to be replaced.

A number of the building’s exterior stucco panels were cracked allowing additional water into the building. To address this issue, an elastomeric wall coating was applied to the panels. Vegetation and planters limited access around the building. This called for the use of swing stages instead of conventional lifts.

The stages were secured using parapet clamps on the roof edges. This allowed for wall access with minimal disruption to the activities below. The building could not be closed for the duration of the repairs. In an effort to minimize further disruptions, the windows were taped and blacked out before work commenced. This extra step not only minimized disruption to those inside the building, but also insured that the building itself would not be damaged.

Moody Gardens Aquarium & Forest

Moody Gardens is an educational destination utilizing nature in the advancement of rehabilitation, conservation, recreation, and research. It’s one of the area’s favorite attractions.

The ten story Rainforest Pyramid completed in 1993 is an important part of the gardens. It is home to more than 1,000 species of exotic plants from Africa, Asia, and the Americas. It is one of the most complete reproductions of an actual rainforest. The pyramid is undergoing a $25 million dollar enhancement.

The exterior cladding of the building moves a great deal. Keeping the interior of the pyramid water tight has always been a challenge. Working with the owners and Morris Architects, Western Specialty Contractors replaced the old sealants with Dow’s 795 Silicone Sealant and preformed 123 silicone strips.

Accessing the work area was difficult because of the sloped glass. A combination of scaffolds, manlifts, and swing stages were utilized.

Despite the tough conditions, Western was able to complete the project safely, on time and within budget.