Rockwool Flexi 100mm x 600mm x 1200mm Insulation 4.32m2

£50.81 £42.34
In stock
Product Description

Rockwool Flexi is a versatile and eco-friendly acoustic and thermal insulation slab that significantly reduces the carbon footprint of a building. This multi-use mineral wool insulation can be used for many applications between metal frames and timber.

Size: 600mm x 1200mm

Pack: 6 Slabs

Other available thicknesses: 50mm, 70mm, 90mm & 140mm

We are happy to help with enquiries, stock availability or any technical help you require, however for security reasons we cannot take orders over the phone. So if you need to chat give us a call on 03301231761 or email us at [email protected].

What is Rockwool Flexi?

Rockwool Flexi 100mm is a lightweight and semi-rigid thermal, acoustic, and fire-resistant insulation slab. This high-quality insulation slab has been created with renewable volcanic rock and patented technology to make it versatile, reliable, and easy to use. It is designed with a unique flexible edge to be fitted between joists, so you can fit your Rockwool Flexi slab in roofs, walls, floors, and partitions without cutting and leaving waste and gaps.


In accordance with BS EN 13501-1, Rockwool Flexi 100mm, along with all other sizes, is rated as A1 non-combustible. This is the highest level of fire resistance, making your building much safer.

Features and benefits of Rockwool Flexi 100mm:

  • Manufactured with the patented flexible edge which ensures a perfect fit is maintained between the insulation and the supporting framework.
  • The insulation is easy to install and can be fitted between fresh timber and will expand into the wider space as the timber dries out and shrinks back.
  • Euroclass A1 is non-combustible and provides additional thermal and acoustic benefits in application.
  • Flexible edge means no cutting and no waste.
  • Multi-purpose with a range of applications.
  • Available in a range of thicknesses.
  • Easy to handle and install.
  • Is resistant to rot, water, and high temperatures.

Applications for Rockwool Flexi 100mm:

  • Pitched roof rafters
  • Framed external walls
  • Internal timber or steel partitions
  • Internal frame ceilings
  • Intermediate floors
  • Separating walls and floors
  • Timber suspended ground floors
  • Party walls

For more information, please read our guide on Rockwool insulation and how it is made as well as how to double layer Rockwool products.

Data Sheet (2.98 MB)
Customer Questions
What u-value does Rockwool Flexi at 100mm give?
The u-value will depend on many factors, which needs to be calculated, and is usually done so by the manfacturer or contractors. The 100mm Rockwool Flexi insulation slabs achieve a thermal conductivity of 0.038W/mK, which is used to calcualte the u-value.
How is Rockwool different to mineral wool?
Rockwool is a form of mineral wool and is manufactured by heating volcanic rock until it melts, and is then spun to create rock fibres. It differs to glass wool as the core product is glass/sand.
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More Information
Supplier Part Number123326
Pack Size6
Size600mm x 1200mm

Orders and Delivery

Free delivery if your order is over £300 ex VAT. Orders between £100 - £300 ex VAT will be subject to a delivery charge of £50 ex VAT. Please note, we are unable to accept orders less than £100 ex VAT

When ordering on line you can specify the date of delivery, however we would not be able to specify the time of delivery on that day.

• Please note that we have a number of large vehicles, including articulated vehicles that may be used for delivery. Please advise us in the comments on your order if access to the delivery address is limited.

• Due to insurance guidelines, delivery personnel are unable to enter private residences. Delivery will be as far as possible to the kerbside of the delivery address. The recipient of the products is responsible for any additional lifting once the delivery has been made. Please bear in mind that Insulation products can be bulky and / or heavy.

• The delivery driver will require a signature to confirm the goods have been received.

 † Unfortunately we, Insulation Express, cannot deliver to the Highlands & Islands of the UK. However we will be happy to deliver to a freight forwarding company on your behalf.


Returns and Refunds

In the unlikely event that you need to return an item, please contact our team on [email protected] within 14 days of accepting delivery of the item.

Restocking charges may apply. We will discuss this with you upon receipt of the cancellation request. Restocking charges will be applied where the products are no longer required AND NOT for goods returned because either defective or damaged.

We usually charge 30% of value (minimum £25.00).

Please note that we cannot accept returns on special orders. Special orders may consist of items sent via third party shipping companies or made to measure products. If you are unsure on whether or not your item is a special order, please contact us on [email protected] prior to placing the order.

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