As part of an overall revitalization plan for the city of Lawrence, Mass., a new, $110 million high school campus was built. Lawrence High School's state-of-the-art campus is the largest high school ever constructed in Massachusetts.
The 25-acre campus consists of six independent, career-themed “academies” that give Lawrence's 3000+ high school students the opportunity to attend a curriculum that is specifically tailored to their future career aspirations. The six academies specialize in Business Management and Finance (BMF), Health and Human Science (HHS), Humanities, Leadership, and Development (HLD), Math, Science, and Technology (MST), Performing Fine Arts (PFA), and International.
While the six academies offer different curriculums, the construction of each building is nearly identical. They are all rectangular, four-story buildings with brick façades. Each building is required, per Massachusetts' most recent energy code, to have an air barrier underneath the façade that covers the entire building envelope, including all four walls, foundation, and roof. The code, dubbed CMR 780, is the first in America to require an air barrier on all new, non-residential construction.
Critical factor
“Stopping building air leaks is critical for improving energy efficiency and preventing moisture related problems, such as mold growth and water damage,” said Brian Carey, air and vapor manager for Carlisle Coatings & Waterproofing Inc. (CCW), a division of Carlisle Construction Materials and a major supplier on the job. “The latest energy codes and a great deal of scientific studies affirm the importance of an air tight building envelope.”
Specifications for installing the air barriers and roofs on Lawrence High School were put out for bids. After review, Acme Waterproofing, Rockland, Mass., was chosen to apply the air barrier to the walls and foundation, and A.J. Desjardins Roofing Co. Inc., Exeter, N.H., was selected to install the roof.
Acme recommended using CCW's Barriseal air and vapor barrier system because of the company's extensive experience with this product and confidence in its performance. Barriseal is a water-based asphalt emulsion modified with a blend of synthetic rubbers and special additives that cures to form a flexible, monolithic membrane on virtually any wall.
A. J. Desjardins elected to install a Carlisle SynTec 60-mil reinforced Sure-Seal EPDM roof system on all of the school's buildings. This company is a division of Carlisle Construction Materials.
Flashing
Before the roofing membrane or Barriseal was installed, Acme applied CCW's full line of 705 flashing products on the buildings'windows, doors, and joints. These products were used to tie-in with the Barriseal and EPDM roof system that would be applied later. The flashing products are 40-mils thick, consisting of a self-adhering rubberized asphalt membrane laminated to a 4-mil or 8-mil high-density polyethylene film. CCW's CAV-Grip primer, an aerosol, was used to install the flashing products.
“Unlike traditional primers, this product allows the user to immediately install flashings without having to wait for it to dry or flash off,” said Keith Sportack, a manufacturer's representative handling CCW products. ”Traditional primers can take up to half a day to dry, depending on the weather conditions.”
Since the buildings on the high school's campus were four-stories tall, much of the work was done from a lift. Acme's crew was able to prime and install the flashing products at the same time, without having to move the lift back and forth waiting for the primer to dry.
