Installing floor insulation can improve energy efficiency – and reduce unwanted noise levels from spaces above by up to eight times. 1

Our range contains dual and mono density stone wool products, resulting in a comprehensive choice of products suited to all common flooring constructions, both for thermal and acoustics applications, with the added benefit of enhanced fire resilience. 

Discover how ROCKWOOL insulation for floors can be applied to several floor applications, from intermediate and floating floors, to suspended ground floors.




Floor Insulation Products

Why do we need floor insulation?

Floors in buildings are magnets for sound, heat and fire to travel through. This can cause long-term issues for tenants and owners, such as nuisance noise, high energy bills, colder living conditions and fire risk.

These problems are becoming ever more common. More than 100,000 homes in London are predicted to be built in high-rise developments by 2030 – a prime location for city noise. 2


Different floor types also need unique insulation solutions to help increase their energy efficiency. These include:

  • Concrete floors – requiring insulation that is suitable for laying on precast concrete flooring. 3
  • Suspended ground floors – optimum thermal property insulation required because of high heat loss risk. 4
  • Intermediate (separating) floors – insulation needs to be adaptable to fit in-between i-joists. 5
  • Floating floors – requiring insulation to adequately fill the space between adjoining floors – to raise acoustic performance.
  • Basement floors – susceptible to losing heat through a concrete floor, requiring robust insulation to improve thermal performance.


Using ROCKWOOL stone wool to insulate floors between, or over, timber or metal joists, or onto a concrete slab or screed, can help to overcome these obstacles.


Optimum insulation can help to:

  • Block out unwanted noise
  • Reduce heat lost through floors
  • Improve a building’s energy efficiency
  • Prevent fire spread and protect the floor structure


ROCKWOOL stone wool floor insulation does this over the lifespan of a building – without deteriorating in performance.

For timber floors the non-combustible properties of our stone wool product range helps to increase fire protection levels. 6

Calculator and savings

To work out how much floor insulation you will need, measure the length and width of your floor space to calculate the area in m². You may want to order slightly more to allow for some excess.

You’ll also need to decide whether you’re fitting in between or over joists, or onto concrete or screed, as this will determine which solution is required.

Work out how resistant your floors are to the flow of noise with our Acoustic Calculator.

Use our U-Value Calculator to determine the thermal performance of ROCKWOOL floor insulation and ensure compliance with the relevant building regulations. 

Floor insulation can also help deliver savings through lower energy bills, particularly for ground floors. The Energy Saving Trust suggests homes with floor insulation installed could make annual energy bill savings of:


  • Detached – £70
  • Semi-detached – £40
  • Mid terrace – £25
  • Detached bungalow – £60 7
Acoustic Calculator
Our floor applications range from thermal products that reduce energy bills, to acoustic products that substantially reduce sound going through a floor. All are designed to help you stay comfortable and safe.

Roger Peeters

Global Product Manager, ROCKWOOL Group

Case studies

The challenge

Property developer Keywest 3 converted an empty high-rise office complex into 43 luxury flats in South Shields, UK.

This ambitious renovation project aimed to minimise noise travelling between apartments, and to improve the building’s wall and underfloor insulation. Originally, the company planned to use 50mm glass wool insulation.

However, the team at Keywest 3 changed their mind after an on-site demonstration of ROCKWOOL floor solutions, which showcased superior acoustic properties and met all of their criteria.

The solution

Keywest 3 picked ROCKWOOL FLEXI® 50mm for this project, deciding to double the material to bolster the sound insulation of the development.

The result

  • Building regulation requirements for soundproofing were surpassed
  • Resident comfort and fire safety were enhanced
  • Thermal efficiency was improved – resulting in reduced tenant energy bills
Utility Wise project - Installer carrying ROCKWOOL insulation on shoulder
Not only will ROCKWOOL sound insulation deliver outstanding acoustic benefits to stop noise transfer in its tracks, it will also reassure residents that their homes are thermally efficient and fire-safe.

Norman Fada

Project Director at Keywest 3
Once installed, ROCKWOOL products can achieve optimal performance. They meet, as well as go above and beyond, building requirements.

Roger Peeters

Global Product Manager, ROCKWOOL Group
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Renovation Case Studies

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FLEXI Datasheet

Download our guides

Financial support

Under the UK Government’s Energy Company Obligation (ECO) scheme, households and buildings may qualify for financial support for floor insulation.

Visit the Office of Gas and Electricity Markets (OFGEM) to learn more.

Energy Efficiency, Key, Keyboard, Button


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What do you use to insulate a concrete floor?
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