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Frequent Asked Questions

Frequent Asked Questions

General questions

What is stone wool?

Stone wool insulation is a rock-based mineral fiber insulation comprised of basic raw materials such as basalt which is a volcanic rock, dolomite and other minerals. The minerals are melted and spun into fibers to produce stone wool.

What is the difference between stone wool and other types of insulation?

ROCKWOOL stone wool is made from volcanic rock and achieves the European Reaction to Fire Classification of A1. It is non-combustible, giving you with critical extra minutes to escape in the event of a fire. 

ROCKWOOL stone wool is also durable; its properties and benefits do not reduce or change over time and will perform effectively for the lifetime of the building, making it a favorable choice for users. It repels water and does not encourage the growth of mold, which meant that it will continue to give the same thermal and acoustic performance throughout the lifetime of the building and without the need for maintenance or replacement.

How long will a ROCKWOOL stone wool product last before I need to replace it?

ROCKWOOL stone wool insulation won’t shrink, it won’t move and it won’t crumble. In fact, ROCKWOOL insulation is so durable; it will maintain its performance for the lifetime of a building.

What acoustic qualities does ROCKWOOL stone wool insulation have?

The open, porous structure of ROCKWOOL stone wool makes it highly efficient in protecting against unwanted noise. In ceilings, around noisy machines, in walls and roofs, ROCKWOOL insulation acts as a natural and effective sound barrier.

It works in two distinct ways to reduce noise by impeding the transmission of sound through an element of the structure or by absorbing sound at its surface.

What environmental impacts/benefits are there from using ROCKWOOL stone wool products?

Our insulation is made from stone, a natural material and produced in a sustainable way. This stone is a renewable and plentiful natural resource, which is continually replenished naturally from within the earth. Our high-tech production process ensures an environmentally responsible approach.

As insulation, it is an extremely cost effective means of improving energy efficiency and it works continuously, requiring no maintenance or replacement over the years.

How do I cut ROCKWOOL stone wool to fit my usage?

It can be easily cut with a long bladed knife. Please ensure all safety gears are worn during the use of insulation. Please contact our local representative for more information.

What density is ROCKWOOL stone wool?

There is no single answer to this. ROCKWOOL products are intended for a wide variety of applications needing different densities.

The versatile range of ROCKWOOL products includes rolls, slabs, boards, mats, pipes, all of which are provided in a range of densities and thicknesses best suited for specific applications.

WWhat happens if ROCKWOOL insulation gets wet?

ROCKWOOL stone wool insulation is moisture resistant yet vapor permeable. This means that in the event the insulation becomes damp or wet, the insulation can be allowed to dry out. When thoroughly dried, it will still maintain its original performance characteristics, provided there is no physical and chemical degradation.

Are ROCKWOOL stone wool products mold resistant?

There is no test method to determine whether or not any product is rodent resistant. ROCKWOOL product’s reputation as a rodent-resistant insulation is mainly based on word of mouth and lack of negative feedback from numerous customers who use our products over many years.

Is ROCKWOOL stone wool toxic?

ROCKWOOL stone wool is fire resilient and non-combustible. It does not emit toxic fumes based on EN and UL certifications; and classified A1 according to EN 13501- Part 1 classification. When tested to ASTM E84, it shows zero for smoke and flame index.

Are ROCKWOOL stone wool products safe to work with?

Yes, stone wool is a safe material to work with. This fact is supported by the decision of the World Health Organisation's International Agency for Research on Cancer (IARC) to exempt stone wool from its list of "possibly cancer causing agents". This conclusion was based on the fact that epidemiological studies provided no evidence of an increased risk of lung cancer from occupational exposure to stone wool fibres, and that there has been no excess of tumors in long-term inhalation studies.

Why is it ROCKWOOL stone wool does not shrink or expand with temperature changes?

This is because ROCKWOOL stone wool, unlike some other types of insulation, is dimensionally stable. This means ROCKWOOL stone wool does not shrink or expand under the influence of temperature differences, resulting in constant thermal performance over the lifetime of the building.

Acoustic Questions

I am insulating a music room. What products do you recommend?

We would suggest lining the walls with a tissue faced slab such as Safe ’n’ Silent. The insulation product would then need to be protected from damage. Typically, this would be achieved by installing a perforated sheet.

Why do I need to use NC as a guide to design my buildings?

NC (Noise Criteria) will provide you with a more holistic reference to the acoustic performance of a room base on its application, as it takes into consideration the partition as well as other elements like doors, windows and HVAC. NC provides a common understanding between the end user and the designer on the acoustic performance required during the design stage.

What should I do if my design and requirements are different from your standard NC recommendation?

The standard NC (Noise Criteria) recommendation in ROCKWOOL Safe ’n’ Silent technical manual is based on typical requirements of the intended room type. If you have a design that is different from the manual please approach a ROCKWOOL representatives for assistance.

How do you verify NRC performance?

NRC (Noise Absorption Co-efficient) can be tested in a lab based on the individual material under ISO 354 / ASTM 423-01. NRC is the representation of the amount of sound energy absorbed upon striking a particular surface. An NRC of 0 indicates perfect reflection; an NRC of 1 indicates perfect absorption.

What parameters will affect the STC value of the building element?

The STC (Sound Transmission Class) rating of a building element is influenced by the assemblies of the building element and works best in mass-spring-mass configuration, where by increasing the mass and the air-space, the STC rating will increase. Infilling the cavity with ROCKWOOL Safe ’n’ Silent Pro improves the transmission loss of the building element, hence giving better STC value. Proper installation of the building element and ROCKWOOL Safe ’n’ Silent Pro need to be ensured in order to avoid air leaks and to achieve optimal performances.

What are the other differences between glass wool insulation and ROCKWOOL Safe ‘n’ Silent Pro?

ROCKWOOL Safe ’n’ Silent Pro is non-combustible, which will provide you with critical extra minutes to escape in the event of a fire. It repels water and does not encourage the growth of mold, which meant that it will continue to give the same acoustic performance throughout the lifetime of the building and without the need for maintenance or replacement.

Industrial Questions

What is the ROI/energy savings with ProRox insulation?

Depending on the processes and system used; the ROI for ProRox insulation can be as quick as less than one year for most industrial applications. 

You may refer to our Corrosion Under Insulation (CUI) brochure for more information.

How long will the insulation last?

For the ideal condition with proper installation, storage and handling, and not tampered with, it can last for the entire life of the plant. However, we also recommend regular inspection to be conducted to ensure your plant efficiency.

Can you conduct thermal insulation calculation for us and provide solution?

Online Rockassist tool is available, which can be used for thermal insulation calculation upon successful registration. We also have a dedicated technical team to support you on this calculation, which will be provided upon special request.

What are the most important factors that need to be considered when selecting an industrial insulation material?

Depending on applications; a good insulation should meet process control requirements, reduce heat loss, as well as protection of personnel and equipment. Insulation should also be considered on its additional function for fire protection, acoustical performance, and reducing CO2 emissions.

Will ProRox insulation prevent corrosion under insulation?

ROCKWOOL ProRox insulation can minimize the risk of corrosion under insulation and we also comply to all relevant ASTM corrosion standards.

Does ROCKWOOL ProRox have a standard specification sheet, which we can use?

Yes, we have a list of specification sheets which will be provided upon request. Please do contact our local sales representatives for more information.

What are the major standards that ROCKWOOL ProRox complies to?

ROCKWOOL ProRox products comply with all International standards namely ASTM, EN and CINI.

Where can I find test certificates for ROCKWOOL ProRox products?

ROCKWOOL ProRox test certificates are made available upon request from our local sales representatives or email your request to us.

Does specially inhibited insulation reduce the risk of stress corrosion cracking?

The assumption when using sodium metasilicate inhibited mineral wool insulation is that the water will seep through the insulation, leaching out inhibitor as well as chloride to cause cracking. However, the vast majority of moisture whether its rainwater, sea water, run off water or droplet condensation on the stainless steel surfaces, is commonly believed to enter the installation without penetrating the insulation at all. Not having passed through the insulation, the water will not be inhibited. Even if water does penetrate the insulation, the very high solubility of the sodium metasilicate will cause almost all the inhibitor to enter the solution at the first time of water ingress.

What type of protection should be used for pipe and equipment conservation?

Protective coatings or paints play a vital role in preventing corrosion under insulation. There are many types of coatings and paints based on organic or inorganic compounds. Each one is designed to protect a specific metal in a specific temperature range.

Can aluminum foil protect austenitic steel surfaces?

It has been proven that aluminum foil applied between the austenitic stainless steel surface and the insulation layer will significantly reduce the risk of stress corrosion in insulated stainless steel surfaces. The foil acts as a physical barrier, it stops chloride-containing fluids migrating towards the stainless steel surface. But the most important effect is that it provides cathodic protection in wet insulation systems, which prevents pitting and cracking. The foil is simply wrapped around the pipe or equipment with approximately 50% overlay to shed water along vertical lines.

Up to what temperature can ProRox wired mats be used on austenitic stainless steel?

Standard ProRox wired mats are faced with galvanized mesh and stitched with galvanized wire. Zinc melts at 419ºC and if it reaches 450ºC it diffuses and penetrates into stainless steel. This can lead to stress cracking within a very short time frame. With this in mind, never use wired mats with galvanized wire mesh and galvanized stitching wire on the hot side of stainless steel, at service temperatures above 350ºC.

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