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30mm White Tissue Faced Two Sides Knauf RS45 Slab (pack of 16)

30mm White Tissue Faced Two Sides Knauf RS45 Slab (pack of 16)
30mm White Tissue Faced Two Sides Knauf RS45 Slab (pack of 16)
30mm White Tissue Faced Two Sides Knauf RS45 Slab (pack of 16)
30mm White Tissue Faced Two Sides Knauf RS45 Slab (pack of 16)
30mm White Tissue Faced Two Sides Knauf RS45 Slab (pack of 16)
  • 30mm White Tissue Faced 2 Sides Knauf RS45 Insulation Slab
  • From 30 up to 240 minutes fire protection (1200x600x30mm slab)
  • Class A1 Non-combustible Rock Mineral Wool Insulation Slab
  • Density 45kg/m3 Thermal conductivity (lambda) of 0.035W/mK
  • Used for structural elements such as concrete car park soffits
Estimated delivery:
In Stock
£ 387.60
Ex VAT: £ 323.00
  • Brand: Knauf®
  • Model: 30mm RS45 White Tissue x2
  • Weight: 16.85kg
  • Dimensions: 1,200mm x 600mm x 30mm
  • SKU: 30mm RS45 White Tissue x2
  • Product code: P1-2916
  • MPN: 30mm RS45 White Tissue x2

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30mm White Tissue Faced Two Sides Knauf RS45 Insulation Slab is a semi rigid A1 class fire resistant insulation slab, used for structural elements such as roofs, concrete car park soffits and similar applications.

Rocksilk RS45 30mm is a standard density (45kg/m3) insulation slab with a certified thermal conductivity of 0.035 W/mK and excellent sound absorption characteristics providing high levels of sound reduction.

The white tissue facings on both sides helps to avoid the slab edges from showing as shadows through the perforated inner sheet and assists in preventing fibre migration (approx. 5 times less fibre migration-bullet).

Knauf RS45 is a non-combustible insulation slab with the best possible Euroclass A1 reaction to fire classification, and is manufactured using Knauf Insulation's unique bio-based binder, ECOSE® Technology.

The 30mm x 600mm x 1200mm Knauf Rocksilk RS45 Soffit Insulation Slab faced with white tissue on 2 sides can provide from 30 minutes up to 240 minutes fire protection to the underside of concrete soffits.

Knauf Rocksilk RS45 White Tissue Faced Two Sides Insulation Slab is used for the thermal, fire and acoustic insulation of soffits in a wide range of both residential and non-residential buildings.

An ultimate White Tissue Faced on Both Sides Knauf Rocksilk RS45 Insulation Slab is suitable for use as an insulated underlining solution in structural soffits such as underground car parks.

Rocksilk RS45 White Tissue Faced 2 Sides Soffit Slabs are odourless, rot proof, non-hygroscopic, do not sustain vermin and will not encourage the growth of fungi, mould or bacteria.

Achieved absorption coefficient of the product will vary according to thickness and density of the slab and application where it is used.

White Tissue Faced (x2 sides) Knauf RS45 will have a life equivalent to that of the structure in which it is incorporated.

Knauf Insulation products made with ECOSE Technology contain no formaldehyde binder, dye or artificial colours.




Thickness: 30mm

Width: 600mm

Length: 1200mm

Pack Quantity: 16

Slab Coverage: 0.72m2

Pack Coverage: 11.52m2

Finish: White Tissue Faced 2 Sides

Density: 45kg/m3 

R-Value: 0.85m2K/W

Thermal Conductivity: 0.035W/mK

Vapour Resistivity: Negligable, Water Repellent

Building Regulations: Class ‘O’ 

Fire performance: Euroclass A1 (non-combustible)


White Tissue Faced 2 Sides Knauf RS45 Insulation Slab Features:

 · Standard Density of 45kg/m3.

 · Free from CFCs, HCFCs.

 · Class A1 Fire classification.

 · A+ BRE Green Guide rating.

 · White Tissue Faced Two Sides Slab.

 · Formaldehyde binder free.

 · High levels of sound reduction.

 · Highest fire rating for non-combustible material.

 · Providing high levels of sound reduction.

 · Acoustic, Fire and Thermal insulation slab.

 · Excellent thermal performance.

 · Standard slab size 1200mm x 600mm.

 · Odorless, non-hygroscopic, and rot proof product.

 · Easy to handle and install insulation.

 · Free of dye or artificial colours.

 · Certified thermal conductivity (lambda) of 0.035 W/mK.

 · Can provide from 30 up to 240 minutes fire protection.

 · Providing approx. 5 times less fibre migration-bullet.

 · Excellent sound absorption characteristics.

 · Manufactured using revolutionary Knauf ECOSE® Technology.


Knauf RS45 (45kg/m3) White Tissue Faced Two Sides Insulation Slab Installation Guide:

 · When fixing a tile or modular system, it is advisable to start with a focus reference slab in the centre of the soffit with subsequent slabs being fixed working towards each edge.

 · The use of string lines or laser alignment equipment will assist in ensuring alignment and squareness of the installation.

 · If installed into concrete or steel composite deck, a pilot hold should first be drilled prior to the fixing being screwed into place.

 · Knauf RS45 Soffit Slabs should be fixed directly to the concrete soffit using Ejot DDS fixings with the Ejot DDT70 washer or similar.

 · Care should be taken not to over-tighten fixings to prevent damage to the Knauf Rocksilk RS45 slab surface.

 · For further information on fixing type and suitability for the substrate, please refer to the fixing manufacturer.

 · It is recommended that all board joints should be staggered and tightly butt jointed.

 · Soffit insulation products should not be used for supporting light fittings or services.

 · Such installations should be supported from the concrete soffit.

 · Where penetrations occur, the boards should be cut locally to ensure a tight fit around the penetration.

 · RS45 Insulation Slabs can be cut slightly oversized to ensure a tight fit under slight compression around the penetration.

 · Any small gaps that result from cutting can be infilled using the Acoustic Intumescent Sealant.


RS45 White Tissue Faced on Both Sides Slab Health and Safety:

 · Knauf Rocksilk RS45 Soffit Liner Slabs (Boards) are easy to handle.

 · Care should be exercised to avoid crushing the edges or corners.

 · Damaged, contaminated or wet products must not be used.

 · During construction exposed areas of slabs should always be covered at the end of a day’s work or in heavy rain.

 · Polyethylene covers should be used to provide protection and prevent work from becoming saturated.

 · It is recommended that the Personal Protective Equipment (PPE) should be used while handling the product.

 · Dust mask (FFP1 minimum), gloves, safety glasses.

 · Knife or fine-toothed saw, tape measure.

 · It is recommended that dust masks, gloves and long-sleeved clothing should be worn during cutting and handling of the product.


*Further information may be found in our Downloads section.

Fairly easy access to all PDF files.

Datasheet ǀ Declaration of Performance - DoP ǀ BBA Certificate ǀ Installation Guide ǀ Certificates ǀ Brochure ǀ SPEC Sheets

Board covarage 11.52 m2
Colour Dark brown ǀ White
Density 45kg/m3 
Fire Protection (Resistance to Fire) from 30 up to 240 minutes
Length 1200mm
Material Rock Mineral Wool ǀ White Tissue Facings x2
Pack Coverage 11.52m2
Pack Quantity 16 slabs
Profile Square Edge
R-Value 0.85m2K/W
Size 30mm x 600mm x 1200mm
Thermal Conductivity 0.035W/mK
Thickness 30mm
Weight/m2 1.46kg
Width 600mm
Fire Classification Class 'O'
Vapour Resistivity Negligable, Water Repellent Slab
Slab Coverage 0.72m2
Building Regulations Approved Document B
White Tissue Faced Yes, Two Sides
Coverage 11.52m2
Fire performance Euroclass A1 (non-combustible)
Finish White Tissue Faced 2 Sides
Quantity 16 slabs per pack
Durability Insulation slab should last the lifetime of your building
Shipping method Articulated Vehicle ǀ Courier
Grade White Tissue 2 Sides Semi-Rigid Insulation Slab 45kg/m3
Sound insulation reduction Up to a factor of eight
Applications Structural elements such as concrete car park soffits
ECOSE Technology Yes, ECOSE® (unique bio-based binder)
ETA Notification Yes
Features Assists in preventing fibre migration
Manufacturer Knauf Rocksilk RS45®

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We deliver insulation materials to Mainland UK only. Deliveries to Highlands, Northern Ireland, Isle of Wight etc.. might be possible at additional cost.
We offer free delivery on most of the orders above £300 (excluding VAT) (except special products - shipping cost via courier - products marked ''Request A Quote'')

Delivery of some insulation materials might be extended due to the current situation (Covid-19, stock shortages, allocations).
If you need materials quickly please contact us - we will do our best to help you source materials needed.

We do not deliver on weekends and bank holidays. Sometimes we can deliver on Saturdays - please check with us before placing the order.
If you need any further information please contact us tel. 02081910776

We can help to calculate price per m2 or linear meter (one meter in length) cost, please just contact us via phone 02081910776, email or live chat. Alternatively, you can work it out yourself quickly and easily: to get cost per meter square please divide price shown in orange area by ''Required area (m2)'' Example price of £28.80 divided by board coverage 2.88m2 = cost of £10.00 per m2.


No matter whether you choose a local installer or a national company, there’s a few tips to help you find the right installer for your home insulation improvements, such as asking for recommendations and making sure that they’re part of a certification scheme. This makes sure that they have the right skills and standards of workmanship to carry out the installation, and you can be sure that they know exactly what they are doing.


1. Thermal inspection picture in portfolio

It’s worth seeing a installer’s previous work. There’s no harm asking if you can see any properties nearby that they’ve installed insulation in. Best way would be to see Infrared Thermal Imaging Inspections. Thermal cameras spot small, but key changes in temperature in different areas of a house, identifying problematic areas that the human eye never could and some that a visual inspection could only hypothesize.

2. Reviews

Along with checking recommendations and previous work, finding reviews online can often be a great way to find out if they provide a good service or not. However, it’s best not to solely rely on reviews you may find or review websites, as there’s no controlling who writes them.

3. Compare prices

Comparing prices will also ensure companies can’t take advantage of you and give you a fair price. 

4. Word of Mouth

The best way to find a great insulation installer is through recommendations. Make sure you ask friends and family. They will most likely give you their honest opinion and can tell you from first hand experience.


Whether you require a wall, cladding, external wall, loft or floor insulation fitted, you can find and hire your local insulation installers from popular UK web pages. A simple internet search will return thousands of potential installers near your area.



We are the stockist of construction materials and related products for both trade and DIY from most recognizable brands in the UK like Cordek, RCM, Promat, Rockwool, Isover, Celotex, Xtratherm, Ursa, Low-E, Cedral, Kingspan, Dufaylite, British Gypsum, K-rend, Ecotherm, Iko enertherm, Kay-Metzeler, Terrawool to allow you to complete your insulation job on time at competitive prices and the highest standards.


Whether you are a large company or a DIYer, if you need a large amount of insulation materials, we can offer quantity discounts at the best prices. Please contact us and our friendly customer service will try to find the best and cheapest solutions for you. We value your time and we will try to deliver the products as soon as possible at a reasonable price to your construction site or house. The UK's leading insulation supplier near you and your needs. Price List available upon request.
30mm White Tissue Faced Two Sides Knauf RS45 Slab (pack of 16)
30mm White Tissue Faced Two Sides Knauf RS45 Slab (pack of 16)
£ 387.60