Rockwool Cavity Slab fulfill Rockwool Insulation

Rockwool Cavity Batts

Full fill cavity batts

Excellent thermal, acoustic and fire insulation.

Suitable for new-build and renovations in masonry cavity and party wall applications.

Can be used in domestic and non-domestic buildings up to 25m high.

Prevents water transmition from outer to inner leaf.

Non-combustible – Euroclass A1.

Durable, rot-proof, water resistant and sufficiently stable to remain effective as insulation for the life of the building.

Does not contain gases that have ozone depletion potential (ODP) or global warming potential (GWP).

Thicknesses and Availability:

This Rockwool Range includes the following readily available product thicknesses 50mm, 75mm, 80mm and 100mm (some thicknesses may only be available in pallet quantities as they will need to be sourced from the manufacturer before being delivered to site).

The following thicknesses are manufactured to order and have minimum order requirements: 120mm (minimum order: 16 x pallets), 130mm (minimum order: 16 x pallets) and 150mm (minimum order: 14 x pallets).

Due to supply challenges from the manufacturers, please allow extended lead times on Rockwool products. Please feel free to contact me to check availability and lead times.

Product Information

General information about Rockwool Cavity Batts

Product Application

Thermal batt for Masonary Cavity walls

Rockwools full fill cavity slab, Rockwool Cavity, is suitable for use in masonry cavity wall construction and masonry party walls between dwellings in both new builds and extensions.

Product Make-up

Core

Durable non-combustable stone wool spun from volcanic rock with water repellent additives which prevent moisture transmission

Facings

Unfaced

Product Properties

Thermal Conductivity 0.037 W/m·K
Nominal Density approx. 45 kg/m³
Fire Performance Classification A1 BS EN 13501-1
Surface Spread of Flame Non-combustable
Slab Length 1.2m
Slab Width 0.455m
Board Edge Square
Vapour Resistance Negligable

Product Prices

Buy Rockwool Cavity Batts

The prices and quantity discounts below are 'per pack' rates. Packs contain multiple batts... 12 x 0.455x1.2m = 6.55m² - in this instance, there are 12 x batts in a pack where each batt is 0.455m x 1.2m providing a total coverage of 6.55m² per pack.

Availability Undetermined - Special circumstances are involved in the supply of these products. Rockwool Cavity 50mm, 12 x 0.455x1.2m = 6.55m² - ranging from £5.02 to £5.25 per m²

1 plus packs @ £5.25 per m² / £2.87 per slab = £34.42 (£41.30 inc-VAT) per pack
3 plus packs @ £5.21 per m² / £2.84 per slab = £34.12 (£40.94 inc-VAT) per pack
5 plus packs @ £5.16 per m² / £2.82 per slab = £33.82 (£40.58 inc-VAT) per pack
7 plus packs @ £5.12 per m² / £2.79 per slab = £33.51 (£40.21 inc-VAT) per pack
9 plus packs @ £5.07 per m² / £2.77 per slab = £33.21 (£39.85 inc-VAT) per pack
11 plus packs @ £5.02 per m² / £2.74 per slab = £32.90 (£39.48 inc-VAT) per pack

Availability Undetermined - Special circumstances are involved in the supply of these products. Rockwool Cavity 75mm, 9 x 0.455x1.2m = 4.91m² - ranging from £6.18 to £6.47 per m²

1 plus packs @ £6.47 per m² / £3.53 per slab = £31.75 (£38.10 inc-VAT) per pack
3 plus packs @ £6.41 per m² / £3.50 per slab = £31.47 (£37.76 inc-VAT) per pack
5 plus packs @ £6.35 per m² / £3.46 per slab = £31.18 (£37.42 inc-VAT) per pack
7 plus packs @ £6.29 per m² / £3.43 per slab = £30.90 (£37.08 inc-VAT) per pack
9 plus packs @ £6.24 per m² / £3.40 per slab = £30.62 (£36.74 inc-VAT) per pack
11 plus packs @ £6.18 per m² / £3.37 per slab = £30.34 (£36.41 inc-VAT) per pack

Availability Undetermined - Special circumstances are involved in the supply of these products. Rockwool Cavity 80mm, 8 x 0.455x1.2m = 4.37m² - ranging from £6.32 to £6.61 per m²

1 plus packs @ £6.61 per m² / £3.61 per slab = £28.90 (£34.68 inc-VAT) per pack
3 plus packs @ £6.55 per m² / £3.58 per slab = £28.64 (£34.37 inc-VAT) per pack
5 plus packs @ £6.50 per m² / £3.55 per slab = £28.39 (£34.07 inc-VAT) per pack
7 plus packs @ £6.44 per m² / £3.52 per slab = £28.13 (£33.76 inc-VAT) per pack
9 plus packs @ £6.38 per m² / £3.49 per slab = £27.88 (£33.46 inc-VAT) per pack
11 plus packs @ £6.32 per m² / £3.45 per slab = £27.62 (£33.14 inc-VAT) per pack

Availability Undetermined - Special circumstances are involved in the supply of these products. Rockwool Cavity 100mm, 6 x 0.455x1.2m = 3.28m² - ranging from £7.81 to £8.17 per m²

1 plus packs @ £8.17 per m² / £4.47 per slab = £26.81 (£32.17 inc-VAT) per pack
4 plus packs @ £8.10 per m² / £4.43 per slab = £26.57 (£31.88 inc-VAT) per pack
7 plus packs @ £8.03 per m² / £4.39 per slab = £26.33 (£31.60 inc-VAT) per pack
10 plus packs @ £7.96 per m² / £4.35 per slab = £26.10 (£31.32 inc-VAT) per pack
13 plus packs @ £7.88 per m² / £4.31 per slab = £25.86 (£31.03 inc-VAT) per pack
16 plus packs @ £7.81 per m² / £4.27 per slab = £25.62 (£30.74 inc-VAT) per pack

Limited stock of the most popular thicknesses are held at most of our depots. Where we need to bring stock in from the manufacturer, please allow up to 2 weeks for delivery

Please observe the 'Star Rating' indicators to assess availability.
Product Availability Excellent Generally 1 or 2 days for delivery
Product Availability Good Generally 1 to 5 days for delivery
Product Availability Fair Generally 5 to 10 days for delivery
Product Availability Poor Generally 5 to 15 days for delivery
Product Availability Undetermined Please call to check availability and approximate lead times

Product availability depends upon stock levels at closest depot and delivery logistics to geographic locations


Product Performance and Guides

Product Performance, Manufacturer Certification, Downloads, and Installation Guides

Thermal Resistance

While we have provided Thermal Resistance values for all thicknesses on the Rockwool Cavity Insulation datasheet, some thicknesses may not be readily available.

Items highlighted in green are generally held in stock at our depots.

Product Thickness Thermal Resistance
Rockwool Cavity 50mm 50mm 1.35 m²K/W
Rockwool Cavity 75mm 75mm 2.03 m²K/W
Rockwool Cavity 80mm 80mm 2.16 m²K/W
Rockwool Cavity 100mm 100mm 2.70 m²K/W
Rockwool Cavity 120mm 120mm 3.24 m²K/W
Rockwool Cavity 130mm 130mm 3.51 m²K/W
Rockwool Cavity 150mm 150mm 4.05 m²K/W

Installing Rockwool Cavity Batts

  • The installation of the batts should commence below the damp proof course (preferably by at least 150mm) with no risk of capillary action to minimise cold bridging. The bottom row of ties should be at 450mm centres horizontally. If necessary, the width of the first course of batts can be cut to suit the height of the next row of wall ties. The width of cut batts should always be 5mm greater than the width to be insulated, e.g. wall tie centres
  • Cut the batts cleanly, using a sharp, long bladed knife and a straight edge.
  • It is recommended that the external leaf be constructed ahead of the internal one so that any mortar protruding into the cavity space from the back of the external leaf can be cleaned off before installing the batts.
  • Build up a complete section of the leading leaf to one course above the next row of wall ties spaced at a maximum of 900mm horizontally. Ensure that all mortar joints are properly filled, particularly the perpends.
  • Before installing each course of batts, excess mortar must be removed from the inside face of the leading leaf, and mortar droppings cleaned from the exposed edges of the batts. This is made easier using a cavity board. This sequence should be maintained progressively until it reaches the wall plate or cavity tray. It is important for the insulation to be carried to the highest level possible.
  • It is essential that all the joints between Rockwool Cavity batts are clean and tightly butted.
  • Raise the second leaf to the same level as the batts.
  • Repeat the above steps to the top of the wall. Alternatively, the top of the batts can be protected by using a cavity tray.
  • To minimise water penetration to the inner leaf during driving rain, it is essential that no gaps are left between the batts.
  • Cut the batts cleanly, using a sharp, long bladed knife and a straight edge.
  • Fit the batts closely around wall openings. Slit them neatly where additional wall ties occur and be careful not to impale or tear them. At corner joints, edges must be cut accurately to ensure close butting.
  • Where two layers of Rockwool Cavity batts are used, ensure that the vertical joints between the outer batts are staggered to those of the inner batts.
  • Minimum order level - £175.00 ex-VAT. For further details on Delivery Charges and Minimum Order levels, please Click Here