Insulation Slabs

(73 Products)

Discover an array of fire-resistant thermal and acoustic insulation slabs, as well as more flexible options perfect for friction fitting. from established brands like Rockwool insulation and Knauf insulation. Suitable for installation in partition walls, masonry cavity walls, external walls, floors, roof spaces, and walls, slab insulation can also be used to create thermal barriers, which reduce heat loss and improve energy efficiency - what's not to like?

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What are Insulation Slabs?

Insulation slab is a rigid slab manufactured from either glass wool, rock mineral wool or sheep’s wool. 

Slab insulation, otherwise known as insulation batt, has great thermal insulation and acoustic insulation (sound insulation) properties whilst also offering fire resistance, meaning it will not ignite or contribute to fire spread.

Due to its rigid composition, insulation slab is far easier to install than loft roll when insulating a pitched roof or upright wall. This is due to the fact that the slabs won’t sag or compress. 

Most insulation slab products fit between joists or studs and help to protect buildings against noise transmission, heat loss and the spread of fire.


Where Can I Apply Insulation Slabs?

Insulation slabs are primarily purposed for use in internal partitions between timber and metal studs, rafters and floor joists.


Rockwool slabs can be used for the following construction types:

  • Interior timber or steel partition walls
  • Interior timber frame floors
  • Interior timber frame ceilings
  • Pitched roofs
  • Acoustic ceilings and partition panels
  • I-joist interior partitions
  • Party walls


Knauf insulation slabs can be applied in general thermal, acoustic and roof insulation such as: 

  • Ground Floors
  • Internal Floors
  • Separating Floors
  • Pitched Roofs at Rafter Level
  • Internal Walls/Partitions
  • Light Steel Frame Walls
  • Timber Frame Walls


For cavity walls, Knauf Earthwool DriTherm Cavity Wall Insulation Slab offers excellent thermal and acoustic insulation in masonry cavity external walls.

To determine the specific applications of each product, please refer to individual datasheets (which can be found in the 'Technical Downloads' of each product page).

Insulation Slab Benefits 

  • Thermal insulation
  • Energy cost savings
  • Improved indoor comfort
  • Noise reduction
  • Moisture control
  • Fire resistance (depending on material)
  • Easy installation
  • Long lifespan
  • Reduced carbon footprint


Rockwool Insulation Slabs

There are many benefits to choosing Rockwool insulation slab. These 1200mm x 600mm slabs are the best acoustic insulation solution on the market; making Rockwool market leaders and a premium brand name within the insulation industry.

These dense, easy to cut slabs are available in varying thicknesses that range from 25mm to 140mm. We recommend these insulation slabs to people seeking a robust 3-in-1 acoustic, thermal and fire insulation solution.

We sell a range of Rockwool slabs; our biggest sellers are the RWA45 (Rockwool sound insulation slab) and Flexi Slab, which has a patented flexible edge. 

Knauf Insulation Slabs

Knauf Insulation Slabs are made up of either glass wool or rock mineral wool; both of which feature a random fibre structure which traps thousands of air pockets, making them perfect heat and sound absorbers.

All Knauf insulation slabs are classed as A1 non-combustible, which is the highest fire classification possible. All slabs we sell are manufactured using Knauf Insulation's unique bio-based binder, ECOSE Technology.

Our most popular sellers from Knauf Insulation is 100mm DriTherm Cavity Wall Insulation Slab 37 and 100mm DriTherm Cavity Wall Insulation Slab 32, which due to the width of slabs ensure a closed joint with adjacent slabs.

Frequently Asked Insulation Slabs Questions

How Should I Store & Handle Insulation Slabs?

Insulation slabs have a soft, fibrous texture and are very light and malleable. Because of this, a serrated blade is all you need to slice through it.
When it comes to storage, we advise that you store the slabs inside; keeping them nice and dry, away from the elements.


Are Insulation Slabs Fireproof?

Insulation slab's fire performance rating is excellent. The slabs can withstand temperatures up to a whopping 1,000 C.

Insulation slabs are classed as A1, the highest possible level on the Euroclass system, which means that they are fire retardant in accordance of BS EN 13162.

What Do The Numbers Within The Insulation Slab Titles Mean?

The numbers on the product names are related to the thermal conductivity of the product. So the lower the number, the better thermal performance that product will give. For example, in the Knauf DriTherm range, the "Therm 37" relates to the product's thermal conductivity value of 0.037 W/mK whilst the 'Dri' refers to the slab's water repellent additive, added to maximise its overall thermal performance. 

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