Fast-Paced Retail Construction

By Paul Fournier | September 28, 2010

A 15-acre retail development in Amherst, N.H., is expected to be ready in less than seven months of groundbreaking, according to a spokesman for the general contractor.

"We started the job in September 2007, and we anticipate having the shell ready for tenant build-out by April 2008," said Bill Walsh, project superintendent for Bowdoin Construction Corp. The Needham Heights, Mass.-based company is the general contractor for the fast-paced project, which is being built for Berkshire Development.

The Golden Triangle

The project is located on Route 101A, one of the busiest thoroughfares in the so-called Golden Triangle of New Hampshire, a heavily populated region between the cities of Manchester to the north, Nashua to the south, and Salem to the southeast. Running east to west from Nashua through Merrimack and Amherst to Milford, Route 101A is straddled by dozens of retail stores and strip malls that prosper in part because the state has no sales tax. Hundreds of thousands of residents of border towns are said to shop each year at retail shops along Route 101A as well as the similarly developed Daniel Webster Highway in Nashua to escape Massachusetts' 5-percent sales tax.

Route 101A's latest addition, the 120,000-square-foot Amherst retail center, will accommodate anchor tenants Sports Authority, Michael's (crafts) and a Circuit City, among other stores. A restaurant and bank have also been proposed for separate structures within the development.

Partly because time is money — a lot of money in terms of lost sales in this hotbed of retail activity — the contractor and its subcontractors are working full bore to get the nearly 3-acre building ready for tenant build-outs. One of these subcontractors is George W. Pynn Masonry Inc. of Plaistow, N.H.

Fraco Platforms Speed Work

Pynn's role is critical because the huge rectangular structure that will house anchors and other tenants is essentially a giant box formed of concrete masonry units (CMU). Pynn's masons, tenders and laborers are erecting perimeter load-bearing walls — some as tall as 28 feet — made up of some 55,000 CMUs. The 8-inch- and 12-inch hollow core units are reinforced with rebars grouted in place between 16 and 32 inches on center, depending on location. Reinforced this way, walls behave structurally like solid concrete.

The Plaistow contractor's employees are working on four Fraco free-standing, mast-climbing work platforms to erect the walls. According to Matt Tremblay, Pynn's general foreman, the four 35-foot-tall units combined can produce a continuous work platform up to 232-feet long. He said each of the mast-climbing units — the heaviest-duty units made by the Quebec, Canada-based company — can support 20,000 pounds.

Tremblay noted the masonry crews are achieving production rates of up to 2,200 CMUs per day with 12-inch block and 3,000 per day with 8-inch block. While the production boost from using Fraco platforms is certainly welcome, said Tremblay, other considerations weigh even heavier.

"The platforms are very mobile, and we can move them easily around the site. But most important is the fact they are very safe."

He added that Fraco set up a mast-climbing unit at the contractor's own yard, and trained, tested and certified the contractor's employees for working with the units.

The Construction Team

Once perimeter walls and interior tubular steel columns are in place, crews will erect joist girders and bar joists for the mechanically fastened EPDM roof. Jay Steel LLC of Amherst is fabricating and supplying all structural steel that is being erected by Aurora Structural Connections Inc. of Mason, N.H., while Quality Concrete of Rindge, N.H., is forming and placing concrete footings, foundation walls and base slabs. Granite State's Milford, N.H., plant is providing the ready mix concrete.

Site work is extensive, with HPB Construction of Bow, N.H., responsible for this portion of the project, including all excavation for buildings, roads, parking lots, and utilities, together with the installation of a large (four, 113-foot by 90-foot cells) precast concrete wastewater leaching system. The latter has been subcontracted to ELD Landscaping of Greenville, N.H., with Phoenix Precast of Concord, N.H., supplying the concrete leaching tanks. Other subcontractors are Stellos Electric of Nashua, J. Lawrence Hall of Nashua (HVAC work), and Continental Paving of Londonderry, N.H.

The retail development's extensive parking lot will feature a pervious asphalt concrete pavement, one of the first installations in the area. Site designers VHB's Bedford, N.H., office called for the unusual pavement, which is said to significantly reduce storm water runoff from such building sites — an environmental benefit.