Knauf Masonry Party Wall Slab is an insulation material made up of glass mineral wool, this slab is a product designed for party wall applications to prevent noise travelling through adjoining walls and separating masonry walls and improve the property thermal performance. The product size is 455mm by 1200mm and is available in thicknesses of 75mm and 100mm. slabs have a density of 18kg/m3 and a water vapour resistivity of 5.00 MNs/g.m.

Although this product cannot be used as a soundproofing material it can improve the acoustic quality of the property and reflect noises, sending them back to the source.

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This product is extremely durable and when installed correctly this product should have a lifespan that is just as long as the buildings. It is odourless, rot proof, non-hygroscopic, does not sustain vermin and does not encourage the growth of mould, fungi, or bacteria.

Key Features:

  • Zero Ozone Depletion Potential (ODP) Zero Global Warming Potential (GWP)
  • Free from CFCs, HCFCs
  • Odourless, non-hygroscopic, and rot proof
  • Does not sustain vermin
  • Moisture tolerant
  • non-wicking
  • Durable and long lasting
  • Easy to handle, cut to size and install
  • Supplied in weatherproof Supakube packaging
  • Excellent acoustic and thermal performance
  • Sized to friction fit between cavity wall ties
  • Lightweight and easy to handle

The flexibility of glass and rock mineral wool means it is easier to install than rigid boards as they can adapt to any slight imperfections in the substrate and knit together and eliminate any air gaps. Eliminating air gaps is crucial to achieving high-quality performance. The slabs are lightweight, flexible on all four sides and easy to handle and install and cut if required.

Knauf slabs are easily cut to size if necessary, using a sharp blade such as a Stanley knife. A heavy ruler or plank of wood can be used to hold the roll as its being cut, and a matt is recommended to ensure the floor or surface is not scratched when cutting. The slabs packaging is for short term protection only and long term the slabs should be stored in weatherproof weather conditions above ground level. If indoor storage is not an option, the correct weather-proofing material should be applied. Knauf slabs should not be left exposed to the elements.

ECOSE Technology is an innovative, new, formaldehyde free binder technology, centred on rapidly renewable materials instead of petro-based chemicals. It lessens embodied energy and provides superior environmental sustainability. ECOSE Technology was developed for glass and rock mineral wool insulation, but offers the same potential advantages to other products where resin-substitution would be an advantage, such as in wood-based panels, abrasives and friction materials.

How does Knauf Masonry Party Wall insulation work?

Knauf Party Wall insulation helps to reduce unwanted noise between adjacent properties when used as part of a Robust Detail construction. The party wall insulation prevent sound from travelling through the walls by acting as a barrier and reflecting the sound back to the original sound source. The party wall insulation will also stop the heat from escaping the building by acting as a block. This will create much better and more comfortable living conditions.

Safety Certifications:
BS EN 13162, EN 50001 Energy Management Systems
ISO 14001 Environmental Management Systems
ISO 9001 Quality Management Systems
Fire: Euroclass A1 to BS EN 13501-1

More Information:
Brand: Knauf
Length: 1200mm
Width: 455mm
Thickness: 100mm, 75mm
Material: Glass Mineral Wool
Density: 18kg/m3


Thickness (mm)Density (kg/m3)Thermal Resistance (m2K/W)Length (m)Width (mm)Area Per Pack (m2)Slabs Per Pack No.

How is Party wall insulation installed?

Always call a specialist to install your Party wall insulation to prevent problems occurring in the future or damages being made to the property. Installing party wall insulation incorrectly can be a very expensive and time-consuming mistake.

Masonry party walls are insulated by drilling a hole in the relevant walls and then injecting mineral wool, polystyrene beads, or fitting insulation materials such as mineral wall slabs into the cavity between the two walls. The hole is then filled, and finishings such as paint can be applied to wall to match the existing walls or to update them with something new.

Internally insulating a party wall –

Another way to insulate a masonry wall is to internally apply insulation to the joining party wall.

Steel or timber battens should be measured and cut to size to create a frame constructed to fit onto the relevant party wall.

The party wall slabs can then be measured and cut to size if necessary to fit within the newly constructed frame and fitted with fixings or adhesive.

Before applying plasterboard, markings can be made on the adjoining walls that line up with the timber or steel frames. This is marked so when the plasterboard is applied you know where the frame is to apply the fixings. Sound proofing plasterboard can then be applied on top of party walls slabs and fixed to the frame.

Another layer of sound proofing material can be applied to the plasterboard if you choose to do so, followed by another layer of sound proofing plasterboards.

Acoustic sealant should be applied all the way around the plasterboard to create a band and seal any gaps between the new and existing walls.

Scrim tape and beading can be applied if necessary and then the plasterboards can be plastered. Paint or wallpaper should then be applied once the plaster is dry to complete the wall.