Making ROCKWOOL insulation in Ranson

The making of our stone wool insulation: an overview of the manufacturing process 

Mineral wool or “stone wool” is a natural product made mostly from volcanic rocks. Natural rocks (such as basalt, dolomite and bauxite) may be supplemented with recycled mineral wool and slag from the steel industry. The stone wool manufacturing process consists of the following eight steps that ROCKWOOL has continued to refine over the course of our 80-year history. 

  1. Material Handling / Charging 
  2. Melting 
  3. Spinning 
  4. Wool Collection 
  5. Curing / Cooling 
  6. Cutting and Marking 
  7. Recycling Plant 
  8. Packing / Unit Load


Take a tour of our manufacturing facilities 

Watch the below video to see for yourself the operations and production of stone wool insulation within our advanced manufacturing production process. 

ROCKWOOL Ranson, Jefferson County, West Virginia final rendering of factory scheduled to open 2020

Advanced Manufacturing Factory Tour

We’re proud of the efficiency and productivity of our manufacturing facilities. They offer a unique combination of state-of-the-art technology and equipment, and people working together to ensure the highest product quality.

Join our mailing list

Keep up-to-date on news and announcements, project information, and job postings from the ROCKWOOL development in Ranson, Jefferson County by subscribing to our Newsletter.


Upholding visibility of the landscape  

Jefferson County offers unique landscapes that are a draw to residents and visitors alike. We take being a neighbor seriously and are upholding stringent conditions regarding the opacity levels of the plume that comes from our stacks. To do this we installed state-of-the-art abatement technology that results in our operations being minimally visible, consisting mostly of evaporated water that disappears rapidly.  

Given the nearby sensitive viewsheds including Antietam National Battlefield and Harper’s Ferry National Historical Park, we partnered with both the West Virginia Division of Culture and History as well as the West Virginia Division of Air Quality to analyze any potential visual impairment due to our facility in Ranson, WV. 

The assessment confirmed that the ROCKWOOL facility will not have any adverse effects on these, or any other property identified by the National Register in the area (Farms: Hazelfield, Tackley, and Rellim Orchard). 

Environmental stewardship in Jefferson County

Our facility has two primary stacks at a height of 213 feet each, the heights themselves being largely determined by the WV DEP and regulations for aviation safety along with dispersion requirements.

See for yourself how we're working hard to minimize our footprint.

You can see the factory. You can see what it looks like. It has stacks. But it doesn’t operate with any visible plume.

Managing truck traffic

ROCKWOOL relies on transportation from trucks to both deliver raw materials to the factory and for delivery of final products to distributors and retailers. 

Factory traffic primarily occurs Monday through Friday and we do not expect our truck traffic for the factory in Jefferson County to be a nuisance to our neighbors or the community. Delete: The total traffic, including employee vehicles, is expected to result in a two percent increase from existing traffic on WV-9. 

Our goal is to ensure the most direct access between the highway and the factory to reduce the impact on local traffic, particularly in relation to schools. From the Ranson site, trucks leave Northport Avenue, turn left on old Route 9, going the opposite direction of North Jefferson Elementary School, and access the highway at Wiltshire (shown in the second visual below). 

Delete: We will keep the public informed if there are any changes to this estimate as the project moves forward. For more information, download our Truck Traffic Fact Sheet.

Creating a safe and environmentally-friendly operation

Production at our 136-acre site in the City of Ranson began July 2, 2021, producing stone wool insulation for residential, commercial and industrial uses. 

Stepping inside our manufacturing facilities, you’ll witness a modern and efficient operation that combines state-of-the-art equipment with people, working together to ensure the highest levels of product quality. 

Health and safety practices

Besides delivering solutions that protect our customers, ROCKWOOL is also committed to providing a safe, fair, and engaging workplace for our employees. We have developed a culture that puts the safety of our colleagues first, including requiring all personnel to wear standard Personal Protective Equipment (PPE). Specific areas of the industrial facility require hearing protection, and some tasks may require additional safety gear that we provide. 

Our indoor air quality does not require employees to wear respirators or dust masks in their regular duties. Specific tasks requiring confined space entry are subject to Occupational Safety and Health Administration (OSHA) regulations and appropriate PPE is provided and used as required along with ensuring regular inspections of all company equipment. 

Video thumb RockWorld, Jens Birgersson, CEO

Safety at ROCKWOOL Group

Get more information about the importance of safety at our organization from CEO Jens Birgersson.

Join our mailing list

Keep up-to-date on news and announcements, project information, and job postings from the ROCKWOOL development in Ranson, Jefferson County by subscribing to our Newsletter.


Water usage and treatment 

At our Ranson facility, we utilize a closed-loop system where rainwater is collected in two secure on-site ponds and used as the primary source of water in the production process.

We have installed a reverse osmosis (RO) system at the factory as standard water treatment equipment. The RO is used to ensure the needed water quality for our production process by limiting deposits and corrosion.

In addition, the Ranson facility uses a water softening plant to remove calcium and magnesium from the water, among other common minerals. This is done to ensure the longevity of the production equipment by limiting deposits (scaling) and corrosion.

As with RO reject water, wastewater from the softening plant has concentrated levels of total dissolved solids and salts. 

Get the full story

Learn more about water inflow, usage and outflow in the production process on our environment page including how we eliminate production water discharge to municipal sewer systems.

Take me there


Prepared in the event of an emergency

At ROCKWOOL, we take all available precautions to prevent an emergency. As part of our emergency preparedness planning, we have conducted a risk assessment that includes risks associated with fire, explosion, and spills. This detailed risk assessment has concluded that no event on-site will cause any evacuation situation for schools and neighbors.

We have also completed hazard mitigation planning to ensure that the facility is fully compliant with a Spill Prevention and Recovery Plan (SPRP) and a Spill Prevention Control and Countermeasures (SPCC) Plan.

Members of the local team are also required to meet rigorous internal controls, which include regular drills carried out in partnership with local fire departments. These drills ensure that the emergency preparedness plans we have put in place can be executed should an event occur. 


1EPA, Workbook for Plume Visual Impact Screening and Analysis (Revised), EPA-454/R-92-023, 1992.

2Reference: County-Wide Groundwater Assessment, Jefferson County, West Virginia, Analytical Sciences Inc for Jefferson County Commission, April 2012

ROCKWOOL officials have been in contact with us and are offering any help, training, or information that will benefit us in mitigating any type of incident at the facility. We have been pleased with the proactive nature of ROCKWOOL officials in offering their help to us as we learn about the new technology on which they have based their processes... The potential of a minor or major incident regarding ROCKWOOL is no different than any other home or facility across the region.

Ross L. Morgan and Marshall DeMeritt

Fire Chief and EMS Chief
See the fire chief’s full statement



Who is ROCKWOOL and what is stone wool insulation?

Founded as a family business, ROCKWOOL has always been committed to strengthening the communities of which we are a part. Today, we are the world’s leading manufacturer of stone wool insulation. Find out about our company history, North American presence, and leadership in the field of fire safety.


Community and Economic Impact

We seek to make a positive impact in the City of Ranson and more broadly in Jefferson County, West Virginia.

By building our state-of-the-art manufacturing facility in Ranson, we are committing to making a long-term and positive impact on the economy of Jefferson County. The $218 million investment includes $64 million in payroll and $4 million in taxes over the first 10 years, in addition to the community support we have already started to provide through partnerships with local organizations.


Jobs Opportunities

Manufacturing jobs and employment coming to Jefferson County, WV.

We are proud to be bringing 150 new manufacturing jobs to Ranson that will provide local workers the opportunity to build meaningful careers in manufacturing a product that is used worldwide to create safe and more sustainable living environments. At ROCKWOOL, we offer employees an attractive benefits package, investments in learning and development, and a supportive workplace culture.



We're protecting the local environment during construction and operations of our manufacturing facility in Ranson.

We have an unbreakable commitment to meeting and exceeding the environmental protection standards set by government and regulators wherever we operate globally, and our facility in WV will be no different. This includes limits established to protect the health of sensitive populations such as children, the elderly and asthmatics, and we continue to invest in state-of-the-art abatement technologies to further reduce any impact.


Construction and Permitting

We're driving investment in infrastructure to attract more business and development for the years to come.

All permits that have been obtained to date for the Ranson facility have been done in accordance with local, state, and federal laws and regulations. We’ve also outlined the site selection process, progress of the development project, and safety procedures that are in place during the construction process.



At ROCKWOOL, sustainability is always top of mind.

While manufacturing any product requires using resources, we are focused on ensuring our products leave the smallest footprint possible during production while delivering the biggest benefit during their use. To accomplish this, we have committed to several UN Sustainable Development Goals and are proud to say that during the lifetime of its use, the building insulation we sold in 2018 will save 100 times the carbon emitted in its production.

Documents and resources



0 selected files