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Rock Wool Manufacturing Company

Tara Strand
Author: Tara Strand
Jennifer Lucarelli
Last Updated: 3/7/2026

Rock Wool Manufacturing Company was founded in Leeds, Alabama, in 1943. Initially, the company produced residential insulation. By the 1950s, it expanded into industrial insulation. Because Rock Wool manufactured insulation with asbestos, the company faced asbestos litigation.
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Logo for Rock Wool Manufacturing Company, an asbestos company

Rock Wool Manufacturing Company History of Asbestos Use

Edward Cusick, Sr., started Rock Wool Manufacturing Company (Rock Wool) in 1943 in Leeds, Alabama. The company, which still has its headquarters in Alabama, manufactured insulation products for residential buildings. As the company grew, it moved into the maritime and industrial sectors. It produced insulation for high-temperature pipes and boats.

Rock Wool was known for its blowable insulation called rock wool or mineral wool. This type of insulation does not typically contain asbestos. But testing showed that some companies that produced rock wool added asbestos. Rock Wool was among the companies that did, leading to many claims of asbestos exposure.

Rock Wool likely used asbestos in their products until the 1980s and possibly beyond. Lawsuits from 1994 found the company negligent for not putting warning labels on its products. Because of the financial burden from litigation, the company filed for bankruptcy in 1996.

Today, the privately owned Rock Wool sells products under the Delta label. The company no longer produces residential blow-in insulation. It focuses on marine, construction, industrial and pipe insulation. Current products comply with asbestos regulations.

Rock Wool Manufacturing Company Asbestos Products

Rock Wool has a long history of supporting the construction industry. The company manufactured cement and other asbestos products for many years. However, trouble started for Rock Wool in 1994 when it faced asbestos lawsuits over Delta Maid, AF and One Shot cements.

Some asbestos products made or used by Rock Wool include:

  • AF Cement
  • Delta Maid High Temp Insulating Cement
  • Delta Maid High Temp-Master Cement
  • Delta Maid One Shot Insulating Cement
  • Gold Bond
  • High Temp-Master Johns-Manville
  • One Shot Insulating Cement

The company name is a synonym for rockwool insulation, which was a popular type of mineral-based insulation. The similarity between the company name and the product name may be a source of confusion for today’s homeowners and renovators.

According to some sources, Rock Wool may have also manufactured asbestos insulation in the past. But current forms of rockwool insulation, regardless of the brand, do not contain asbestos.

Message bubble with 'i' icon for information about mesothelioma Did You Know? Mesothelioma victims may be eligible for compensation from more than one asbestos trust fund. Filing a claim with one trust does not impact your eligibility for compensation from another trust fund. Learn More About Accessing Trust Funds

Rock Wool Manufacturing Company and Occupational Exposure

Like many industries, manufacturing once relied on asbestos for the mineral’s durability and heat resistance. Rock Wool produced many different products for the construction industry. However, manufacturing and selling asbestos products risked exposing people to the mineral. Employees and others who came into contact with Rock Wool products risk developing an asbestos-related disease.

People in the construction and marine industries may have experienced exposure. Some jobs with higher exposure risk include construction workers and insulators. Also, secondhand exposure could happen when people who worked in these industries brought the dust home on their clothing and hair. People exposed to asbestos secondhand may develop mesothelioma or other illnesses.

Occupations Impacted by Rock Wool Manufacturing Company’s Asbestos Use

Asbestos Lawsuits Against Rock Wool Manufacturing Company

As early as 1994, Rock Wool faced lawsuits over its asbestos use and negligence.

In one case, seven employees from a shipyard filed a lawsuit against Rock Wool and other asbestos companies. The employees alleged these companies manufactured and sold asbestos products that exposed them to the mineral.

Shipyards had asbestos in many different areas. Because of this, the workers were exposed in multiple locations of the shipyard. Each of the seven developed asbestos-related diseases, including asbestosis and lung cancer.

The court ruled in favor of the shipyard workers and declared Rock Wool partially liable. The court ordered the company to compensate the employees a total of $1.25 million. Rock Wool appealed the decision, but the appeals court affirmed the case.

Rock Wool faced nearly 150,000 lawsuits. As a result, the company opted to declare bankruptcy and reorganize in 1996.

Questions About Filing a Claim Against Rock Wool Manufacturing Company? Ask experienced mesothelioma advocate Jennifer Lucarelli Ask a Question

Rock Wool Manufacturing Company Asbestos Trust Fund

Rock Wool Manufacturing established the Rock Wool Manufacturing Company Asbestos Trust in 1999. The asbestos trust fund let Rock Wool set aside money to help ensure asbestos victims got the compensation they needed.

Records do not show how much money Rock Wool initially put into the trust or the total number of mesothelioma claims. Currently, the fund is inactive.

Anyone who has developed an asbestos-related disease from Rock Wool products should speak with an attorney. An experienced mesothelioma attorney can provide options for compensation.

Common Questions About Rockwool

Is rockwool insulation carcinogenic?
According to regulators, the rockwool type of insulation isn’t necessarily carcinogenic. But older Rock Wool brand products might be if they contain asbestos. A professional asbestos inspector can help determine if materials in your home pose a threat.
Is rockwool insulation safe to breathe?
Breathing rockwool insulation is likely unsafe and may negatively affect your health. To protect workers, the Occupational Health and Safety Administration (OSHA) limits workplace exposure to the fibers found in rockwool insulation.
Should I remove old rockwool insulation?
In older homes, many types of insulation could contain asbestos. Homeowners should never attempt to remove asbestos-contaminated items on their own. Instead, you can have professionals test the suspicious products and remove any asbestos materials.
Sources
  1. Asbestos Resolution Website. Background & History: Rock Wool Manufacturing Company Asbestos Trust.‌

  2. BhamWiki. Rock Wool Manufacturing Company.

  3. InspectAPedia. Asbestos Content in Mineral Wool or “rock wool” ?

  4. Johns-Manville Corporation. Asbestos: The Magic Mineral.

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Tara Strand, Senior Content Writer at Mesothelioma.com
Written by Tara Strand Senior Content Writer
Jennifer Lucarelli
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