Historic Mill Building Restored with Sponge Media


Global manufacturer of dry, low dust, recyclable abrasive blasting media and related equipment, Sponge-Jet (Newington, New Hampshire) was recently reported to have played a role in remediating an historic mill building in Altoona, Pennsylvania.

According to reports, crews were quickly challenged by the structure’s lead coatings found along three different substrates: Southern Golden Pine wood beams and trusses, steel columns and brick interior walls.

About the Mill

The Old Altoona Silk Mill first opened in 1889 after being financed by a New Jersey-based company and a public bond issued by Altoona residents. At the time of its construction, the structure encompassed 100,000 square feet.

After two years, the mill was closed, causing city bond-holders to lease the property to a Swiss silks manufacturer. It was then that the company expanded the structure’s footprint through the construction of an annex across the street and boiler plant to power the mill’s machines.

Around the time that the power plant was built, in 1901 an engineering report indicated that the mill housed 40,000 spindles and 600 looms. In 1932, however, the mill would close again.

Some time later, the complex was repurposed by a pair of U.S. clothing manufacturers. In the 1990s, some of the buildings were demolished, and the remaining ones were repurposed into an office park.

Renovation Project

According to the Keystone Edge, construction and renovation efforts were halted for several months because of necessary lead abatement which posed logistical, environmental and economic challenges.

“Every square inch had lead paint,” said John Radionoff, President of complex owner Silk Mills Properties, Inc. Radionoff was reported to be involved with the renovation efforts since the beginning of the project and even steered the design of the layout and exterior via extensive research into the site’s history, as well as study of existing architecture in Pittsburgh and New York City.

After review with environmental consulting firm, Environmental Hazard Controls (EHC), it was decided that the lead paint removal would have to be completed without water due to the building’s wooden substrates. In total, the project would require 240,000 square feet of lead abatement. This included 150,000 square feet of wood surfaces, 83,000 square feet of brick surfaces and 7,000 square feet of steel.

While EHC considered several different lead removal and surface preparation methods for the project, such as a lead-lock coating systems, abrasive blasting and chemical stripping, it was decided that crews would use Silver 60 Sponge Media by Sponge-Jet on all three substrates.

The decision was made based on the media’s ability to not damage the substrates and that it would be more efficient in removing all of the lead paint from various cracks and imperfections, in addition to not resulting in massive amounts of potentially harmful dust and waste.

According to Sponge-Jet, there was 200-300 microns (8 to 12 mils) of failing lead paint covering all three substrates, making the lead abatement process even more daunting. Despite this task, the company reported that sponge blasting also cost significantly less than it would have to prepare the wood substrate and apply the lead-lock coating, estimated at a cost of an additional $80,000.

The combined environmental assessment and mitigation, however, would run upwards of $4 million.

In its report, the company noted that the sponge media blasting was “equally as productive as traditional grit on the steel columns and the brick walls, but much easier to contain and clean-up, and produced little to no dust during the blasting process.” The Sponge-Jet Regional Manager on the job added that, “rather than sealing in the liability [on the wood], the contractor completely removed it.”

Overall, by using Sponge Media on this project, significantly less abrasives were consumed lowering the cost of hazardous disposal 92-94%.

After surface preparations were carried out, renovation crews worked to remove the steel lintels that blocked the arches of the original building’s windows. Reports indicate that each of the removed lintels were reutilized in the new design.

The revamped complex is the result of a major partnership between the City of Altoona, ABCD, the Pennsylvania Department of Community and Economic Development (DCED)—who contributed more than $6 million to launch the rehab—and the private sector.

“It was clever of them to realize, why are we taking up this beautiful land when we have all these blighted mill structures in Pennsylvania?…Why can’t we apply the same financing to rejuvenate these structures?” explained Radionoff. “We saw an opportunity to create something that I don’t think exists elsewhere in Blair County.”

With the Mill’s DCED funding, renovations were able to include elevators installations, new parking lot construction and stairways. In the future, the partners hope that the mixed-use facility, which includes potential office and coworking space, room for a restaurant or café and to-be-constructed luxury apartments on the fourth floor, will attract new and local businesses.

Other possible targets include local businesses who want to open a new training facility or HR hub, or trucking and manufacturing firms looking to recruit college-educated office workers to more rural job sites.

Editor's Note: This article was updated on Wednesday, March 9, 2022, at 11:03 a.m. to correct the estimated cost of surface prepartions.


Tagged categories: Abrasive blasting; Abrasive recycling; Abrasives; Commercial / Architectural; Commercial Buildings; Completed projects; Historic Structures; Lead; Lead; Lead paint abatement; Maintenance + Renovation; Maintenance programs; NA; North America; Program/Project Management; Project Management; Renovation; Sponge blasting; Sponge-Jet; Surface preparation; Surface Preparation - Commercial

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