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Mineral Wool Insulation

Mineral wool is an effective form of insulation and is designed for high thermal performance, fire resistance & acoustic soundproofing.

Our Rockwool and Knauf mineral wool slabs can be easily cut down to size making them ideal for many applications including pitched roofs, walls and floors. Available in thicknesses ranging from 30mm up to 150mm, you can find the right insulation for your needs.

If you are looking for wool insulation with excellent acoustic strengths, effective thermal capabilities and fire-proof properties check out our dedicated selection of mineral wool insulation slabs below and benefit from next-day delivery when you place your order before 12 pm (please see product page for more information on lead times.)


High-Quality Mineral Wool Products

Mineral wool insulation is the ideal solution for improving your home's thermal performance, fire resistance and soundproofing.

Our product range features Rockwool & Knauf, two of the UK’s leading manufacturers of sustainable fireproof wool insulations. We guarantee a high thermal performance that can withstand harsh weather conditions, making it ideal and effective for any type of home.

If you are interested in acquiring excellent, affordable mineral wool insulation slabs in the UK, check out our selection today.

High-Temperature Mineral Wool

Rockwool Flexi Slab

Rockwool Flexi Slab is a versatile insulation material designed for multiple uses, providing both acoustic and thermal insulation. It features a flexible edge along one side to ensure a perfect fit with the support framework.

The Flexislab is classified as A1 non-combustible, providing ultimate fire resistance. It is easy to install and suitable for a variety of applications including pitched roofs, framed external walls, internal partitions, intermediate floors, separating walls, and floors.

Knauf Rocksilk RS45

Knauf Rocksilk RS45 is an insulation material designed for use in various thermal and acoustic applications where density is crucial. It is non-combustible and classified as A1, providing excellent fire resistance.

One slab of Knauf Rocksilk RS45 can be used for multiple applications. It can also serve as a sound-absorbent lining, combined with perforated metal liner sheets, to control the reverb of internal sound. This versatile insulation material can be used for ground floors, internal floors, separating floors, fabrication, pitched roofs, internal walls, and light steel frame walls.

Knauf Rocksilk Rainscreen Slab

Knauf Rocksilk Rainscreen Slab is BBA certified and suitable for use in all types of buildings, including those above 18 metres in height. It can be used in timber frame walls, rain-screen facade systems, and frame construction with a masonry outer layer.

The slab is designed to be used as sheathing insulation in a rain-screen facade system. Additionally, it is non-combustible and classified as A1 for fire protection. It also contains a water-repellent additive that ensures its integrity when left exposed.

Acoustic Sealant

Fire and smoke can enter through the smallest of gaps, so if there are any impurities in your walls, it’s a good idea to seal them up.

Our acoustic sealant is specifically designed to provide superior fire resistance, forming a barrier offering up to 4-hour fire protection. Not only does it protect against fire & smoke, but also provides excellent acoustic performance.

It is easy to apply and comes in a 310ml cartridge, making it the ideal choice for both professional contractors and homeowners.

What are the benefits of mineral wool?

Mineral wool is a breathable insulation material that will keep your home warm in the winter and cool in the summer. With excellent thermal performance, you’ll benefit from reduced energy costs as you are less reliant on artificial heating.

Rockwool and Knauf's slabs are made from rock mineral wool which makes them fire-resistant and will slow down the spread of flames.

Mineral wool is designed to reduce and block decibels from travelling through walls, which is useful if the wall is being shared with a neighbour or you live near a noisy road. If you are looking to make the room as soundproof as possible, take a look at our acoustic installation page which includes rubber base underlays and Regupol flooring.

Trusted Supplier

UK Flat Roofing is a trusted supplier of mineral wool insulation, with happy and trusting customers across the UK. With nationwide delivery, you can place your order before 12pm and we'll dispatch it to you the next day. With over 35 years of experience, our expert team is on hand to help with any questions you may have; simply contact us on WhatsApp or visit our contact page.



Mineral wool, also known as stone wool, rock wool & slag wool, is a non-metallic material manufactured from a controlled mix of raw materials ranging from stone or silica, which are then shaped into rolls or slabs to fit into walls, roofs or floors. This insulation is ideal for homes or properties that need to achieve a fireproof standard as Rockwool has a Euroclass A1 rating.

Yes! As mentioned above, mineral wool insulation is known for its high-quality, acoustic benefits, effective heat retention and fire resistant properties. Many trusted manufacturers for insulation (such as ROCKWOOL, Knauf Earthwool, etc.) are known to deliver these types of insulation products as well, due to their various benefits for different types of properties.

Mineral wool insulation is highly recommended for those looking for high-grade insulation for their home or property. .

Mineral wool insulation is fireproof, meaning that they do not conduct high temperatures. Due to this advantage, mineral wool insulation is fit for environments that put high demands on fire safety protocols.

This means that mineral wool insulation is often used in partition walls, ceilings, and features of your home that demand high fire resistance.

Yes, you will always need a vapour barrier for your mineral wool insulation. Without a vapour barrier, dampness can begin to occur, resulting in mould and rot building up.

Mineral wool is simple to cut but should be done carefully with a sharp knife to ensure it is as even as possible.

Draw lines on the material where you intend to cut ensuring that it fits in the required space.