June Residential New Build Render and cladding walls

June 2010 Residential New Build 2.5.4 Render and cladding walls

Residential new build 2.0 Residential New Build Render and Clad Contents Introduction find online page Solution optimiser and pathfinder 194 Design considerations 196 Design Details 602 find online page Render on insulation (mechanical fix) Er01 602 Render on insulation (adhesive fix) Er02 602 Insulation behind cladding Er03 604 Insulation behind cladding Er04 604 Rainscreen cladding Er05 606 Curtain walling Er06 608 Light steel frame with rainscreen cladding Ls03 600

2.5.4 Residential new build: Walls Render and cladding walls Solution optimiser and pathfinder Rocksilk Krimpact Facade Slab is suitable for use in a wide range of installation processes, including mechanical or adhesive fix, or in a rail system. It also gives you more options, as it's compatible with all the major external wall insulation systems providers. Rocksilk Krimpact Facade Slab has hidden strength too which makes it ideal for use behind a render finish. The unique Krimpact technology re-aligns the insulation s mineral wool strands during manufacture to give it a solid, compressive strength with more consistent density and high impact resistance. Yet it s still a lighter, thinner product than other insulants with no compromise in thermal, fire resistance and acoustic performance. Render on insulation Creates a dwelling with high thermal mass which is ideal for properties in continuous occupation and can also help to restrict overheating in summer Includes application of decorative and weatherproof render Removes risk of surface condensation forming Improves acoustic performance Rainscreen cladding Lightweight alternative to masonry cladding Fast to erect Available in a very wide range of decorative finishes Creates a dwelling with high thermal mass which is ideal for properties in continuous occupation, and can also help to restrict overheating in summer Removes risk of surface condensation forming Improves acoustic performance Light steel frame with rainscreen cladding Lightweight alternative to masonry cladding particularly suitable for high rise buildings Fast to erect Available in a very wide range of decorative finishes 194

Residential new build: Walls 2.5.4 External walls with render and cladding Construction compatibility with 5/6* by 2016 Code for Sustainable 4* by 2013 Homes rating 3* by 2010 Part L1A by 2007 Knauf Insulation solution U-values 0.33 0.32 0.31 0.30 0.29 0.28 0.27 0.26 0.25 0.24 0.23 0.22 0.21 0.20 0.19 0.18 0.17 0.16 0.15 0.14 Render on insulation (mechanical fix) Product*: Rocksilk Krimpact Facade Slab Description: Compression resistant rock wall insulation slab mechanically fixed to external wall, with render Page No: 602 Er01 Render on insulation (adhesive fix) Product*: Rocksilk Lamella Slab Description: Available for use in adhesively fixed external wall insulation systems. Details of proprietary manufacturers from Technical Advisory Centre 01744 766666 Page No: 602 Er02 Insulation behind cladding Product*: Earthwool Universal Slab CS24 Description: Glasswool insulation between timber battens and behind cladding Page No: 604 Er03 Insulation behind cladding Product*: Earthwool Universal Slab RS60 Description: Rock mineral wool insulation behind and between timber battens and behind cladding Page No: 604 Er04 Rainscreen cladding Product*: Earthwool RainScreen Slab Description: Rock mineral wool insulation behind rainscreen cladding Page No: 606 Er05 Curtain walling Product*: Earthwool Universal Slab RS45 or RS60 Description: Rock mineral wool insulation in curtain walling system Contact system manufacturer for u-values Page No: 608 Er06 Light steel frame with rainscreen cladding Products*: Earthwool SteelTherm Earthwool RainScreen Slab Description: Glasswool between studs of mm frame, cement fibre sheathing board supporting rock mineral wool insulated rainscreen cladding Ls03 Page No: 600 Key Thermal insulation achievable by constructions within this document. * Recommended Knauf Insulation product(s). Other products may be applicable. Pb01 Find online. Visit www.knaufinsulation.co.uk and key in construction code to find the most up to date information on your chosen solution. 195

2.5.4 Residential new build: Walls Render and cladding walls Render and cladding design External insulation of solid masonry walls has the benefit of keeping the structure warm. The thermal mass of the masonry external walls helps to keep temperatures stable storing heat in the winter and reducing solar gains in the summer. External wall insulation Whilst the vast majority of cases where external wall insulation is adopted are refurbishment projects, it is a valid method of construction in new build housing. In many circumstances it will be installed outside a masonry wall and in these cases the resulting dwellings are likely to have high thermal mass which has the effect of storing heat in winter and restricting summer overheating. Also installing the insulation outside the main structural wall enables the use of details at junctions and openings that minimise thermal bridging. As a cladding option both render and rainscreen systems are lightweight when compared to brick and masonry. Weather protection All forms of external wall insulation need a protective finish or cladding to protect the insulation from the weather. The protective cladding can take many forms, some of which are proprietary systems, rainscreen cladding for example. Whenever a proprietary system is used, the system manufacturer s recommendation should be followed. Where a more traditional cladding, such as tile hanging is proposed, then standard good practice details should be followed. Render finishes The wide variety of colour and texture available in renders offers architects great scope in creating attractive yet practical designs. A number of proprietary renders are available as alternatives to traditional sand/cement renders. Specialist manufacturers should be consulted regarding the specific requirements for their products. Render on insulation is subject to greater temperature fluctuations than render applied direct to masonry. The following precautions should be adopted to minimise cracking: Reinforce the render with a mesh Provide movement joints at maximum 5m centres Use a light coloured finish to minimise the effects of solar gain and thermal movement Use a render incorporating a polymer and/or reinforcement fibres Galvanised or stainless steel beads should be provided at structural joints, at angle changes and around structural openings, as well as at movement joints. In refurbishment projects, sill and head drips are likely to need extending or reforming. The insulation should be returned into reveals and soffits at openings to avoid thermal bridging. Fire Where a combustible insulation is used behind render, the reinforcement mesh must be securely fixed through the insulation to the substrate. In addition, non-combustible cavity barriers must be provided at each storey to comply with the Building Regulations - further guidance is given in BR135, published by the Building Research Establishment. design detail finder Knauf Insulation solutions for these types of construction can be found on ±pages 602-609. 196

Residential new build: Walls 2.5.4 Typical details Window head detail Ensure wall insulation having a minimum R-value of 0.6m 2 K/W overlaps the window frame Drip flashing Window sill detail Composite window Metal sill Blockwork Insulation board Render with reinforcing mesh Ground floor detail DPC Belcast drip to base of render Calcium silicate board facing to insulation board Wall insulation to extend at least 200mm below top of floor insulation to meet Accredited Construction standard Polyfoam High Impact Board is ideal for this application 197

6.2.3 Design details: Light steel frame walls Light steel frame walls Glass or rock mineral wool between studs, rainscreen cladding Advantages Ls03 Ls04 3 Earthwool SteelTherm Roll 40 or Earthwool Flexible Slab to fit tightly between standard stud widths 3 The insulation is compressible and can be cut slightly oversize to friction fit preventing cold air penetrating through joints 3 Earthwool SteelTherm Roll 40, Earthwool RainScreen Slab and Earthwool Flexible Slab are non combustible products with a Euroclass A1 classification 3 Improves acoustic performance of walls Vapour control layer Earthwool SteelTherm Roll 40 or Earthwool Flexible Slab between steel studs Cement fibre board Thermal break pads Rainscreen brackets fixed back to structural frame Double layer of plasterboard Earthwool RainScreen Slabs fixed back to cement fibre board Vertical fixing rails Rainscreen cladding Products Earthwool SteelTherm Roll 40 is a lightweight glass mineral wool. Its manufacture has a very low impact on the environment and is classified as Zero ODP and Zero GWP* Earthwool Flexible Slab is a multi-purpose flexible, friction-fit, rock mineral wool slab. Its manufacture has a very low impact on the environment and is classified as Zero ODP and Zero GWP*. Earthwool RainScreen Slab is a rock mineral wool slab containing a water repellent additive, specially developed for rainscreen cladding applications. Its manufacture has a very low impact on the environment and is classified as Zero ODP and Zero GWP* * Ecohomes and Code for Sustainable Homes classification Typical construction Inner leaf comprising a double layer of plasterboard, vapour control layer and Earthwool SteelTherm Roll 40/Earthwool Flexible Slab between steel studs. A cement fibreboard is fixed to the outside of the frame and insulated with Earthwool RainScreen Slabs fixed back to the cementitious board. A range of rainscreen claddings can be applied, supported from brackets fixed back to the steel studs, a thermal break pad is incorporated between the brackets and the cementitious board. Installation Cement fibre boards fixed outside the steel frame, EarthwoolFrameTherm Roll 40/ Earthwool Flexible Slab is friction fitted between the studs at standard centres and is self supporting. A vapour control layer is taped to the studs across the inner face of the wall before fixing the plasterboard. The vapour control layer should be free from holes. Any gaps should be made good, tears repaired and overlaps and apertures for services effectively sealed. Particular care is necessary around electrical boxes. The rainscreen cladding support brackets are fixed to the frame through thermal break pads as required for the rainscreen system. Earthwool RainScreen Slabs are positioned between the support brackets for the rainscreen cladding. To minimise thermal bridging, the brackets should be of sufficient depth to allow the panel support rails to be located clear of the face of the insulation. The insulation should be close butted and fixed independently against the building substrate using proprietary insulation fasteners in accordance with the design specification. Once the insulation is firmly in place, the application of the cladding can proceed. Ensure that a ventilated cavity remains between the insulation and the external cladding. The dimensions of the ventilated cavity should not exceed the limits in the Building Regulations. Performance Thermal performance Earthwool SteelTherm Roll 40 has a thermal conductivity of 0.040 W/mK. Earthwool Flexible Slab has a thermal conductivity of 0.035 or 0.037 W/mK. Earthwool RainScreen Slab has a thermal conductivity of 0.035 W/mK. Tables 50-53 give U-values for typical light steel frame walls insulated. Fire performance Earthwool SteelTherm Roll 40, Earthwool Flexible Slab and Earthwool RainScreen Slab are classified as Euroclass A1 to BS EN ISO 13501-1. 600

Design details: Light steel frame walls Typical junction of external with terracotta rainscreen and separating wall Terracotta tile rainscreen cladding system Earthwool RainScreen Slab Typical specification External wall to be insulated between studs using Earthwool SteelTherm Roll 40/ Earthwool Flexible Slab*...mm thick. Insulation to be cut as necessary and friction fitted between studs. Pads to provide thermal break Vapour control layer behind plasterboard Earthwool SteelTherm Roll 40 or Earthwool Flexible Slab between studs 6.2.3 Steel frame separating wall, Robust detail E-WS-1 shown (*delete as appropriate) Earthwool RainScreen Slab...mm thick to be fixed independently to the cementitious board facing to the steel frame using proprietary insulation fasteners in accordance with the design specification. The insulation should be close butted and fitted around all adjacent parts of the rainscreen support brackets to minimise any thermal bridging. Once the insulation is firmly in place the application of the rainscreen cladding can proceed. Cavity barriers and fire stops should be installed as required to meet the Building Regulations. Alternatively, refer to NBS clause P10/210. Table 50: mm steel studs insulated with Earthwool SteelTherm 40 with Earthwool RainScreen Slab outside the frame Ls03 U-values (W/m2K) U-value (W/m2K) Earthwool SteelTherm Roll 40 (mm) Earthwool RainScreen Slab (mm) 0.32 90 50 Table 52: mm steel studs insulated with Earthwool Flexible Slab with Earthwool RainScreen Slab outside the frame Ls04 U-values (W/m2K) U-value (W/m2K) Earthwool Flexible Slab (mm) Earthwool RainScreen Slab (mm) 0.31 50 0.27 90 75 0.27 75 0.24 90 0.24 0.22 90 125 0.21 125 0.20 90 0.20 0.19 90 175 0.18 175 0.18 90 200 0.17 200 Table 51: mm steel studs insulated with Earthwool SteelTherm 40 with Earthwool RainScreen Slab outside the frame Table 53: mm steel studs insulated with Earthwool Flexible Slab with Earthwool RainScreen Slab outside the frame U-values (W/m2K) U-values (W/m2K) U-value (W/m2K) Earthwool SteelTherm Roll 40 (mm) Earthwool RainScreen Slab (mm) U-value (W/m2K) Earthwool Flexible Slab (mm) Earthwool RainScreen Slab (mm) 0.28 140 50 0.27 50 0.24 140 75 0.23 75 0.22 140 0.21 0.20 140 125 0.19 125 0.18 140 0.18 0.17 140 175 0.17 175 0.16 140 200 0.16 200 Sales 0844 800 0135 Technical Advisory Centre 01744 766666 www.knaufinsulation.co.uk 601

6.2.4 Design details: Render and clad walls Render and clad walls Render on insulation (mechanical fix) Advantages 3 Compression resistant insulation slabs offering a high level of support to render 3 Joints between the slabs knit together preventing cold bridging 3 Non-combustible insulation requires no cavity barriers, making installation quick and simple 3 Moisture repellent insulation Er01 Existing wall Er02 Insulation fastener Rocksilk Krimpact Facade Slab 3 Rocksilk Krimpact Facade Slab is a Zero ODP and Zero GWP insulation product Reinforcing mesh Render Products Rocksilk Krimpact Facade Slab is a high impact strength rock mineral wool slab with a water repellent additive specially developed for external wall insulation systems. Its manufacture has a very low impact on the environment and is classified as Zero ODP and Zero GWP*. * Ecohomes and Code for Sustainable Homes classification Typical construction Existing or new solid masonry wall with external insulation of Rocksilk Krimpact Facade Slab with a render finish. Note that Rocksilk Krimpact Facade Slab is used as the mineral wool solution in many proprietary external wall insulation systems available on the market. Installation Mechanical fix: Rocksilk Krimpact Er01 Facade Slab is easy to cut with a knife or saw to fit around openings. Remove all loose and flaking materials from the wall, making good all hollow areas to give a smooth, stable substrate. Temporarily fix Rocksilk Krimpact Facade Slab using simple friction fit mechanical fixings. These are sufficient as temporary fixings but must not be relied upon as the final structural fixing. Use one or two fixings per slab. Secure expanded metal lath using specialist fixings such as EJOT TID and DH, which extend through the insulation into the masonry wall. Normally nine fixings per square metre are required, but this largely depends on the pullout force achieved by the particular fixing being used and the nature of the substrate. Please refer to fixing manufacturer for further information. Provide beads around openings, at corners and at the perimeter of the insulated area, at structural joints and to form expansion joints. Where DPCs occur, they should be extended through the insulation and render. Apply render in two coats. Proprietary renders should be applied in accordance with manufacturer s instructions. Rocksilk Lamella Slab is available for Er02 use in adhesively fixed external wall installation systems. Details of proprietary manufacturers can be obtained by contacting our Technical Advisory Centre team on 01744 766666. 602

Design details: Render and clad walls 6.2.4 Typical detail at junction with pitched roof (existing solid brick wall upgraded) LR roofing underlay Roof insulation taken over wall plate to link with wall insulation Rocksilk Krimpact Facade Slabs with render finish Existing wall Typical specification Fix Rocksilk Krimpact Facade Slab... mm thick to the substrate with temporary fixings/ adhesive. Expanded metal lath... (material/ reference) to be fixed through the insulation into the wall using... fixings. Provide stop and drip beads around openings, at corners, at base of insulation and at DPC level. Form expansion joints using... beads at minimum.m horizontal and...m vertical centres. Horizontal joints to align with... (e.g. window heads). Apply two coat render as specification clause... National Building Specifications (NBS) based on standard version J42, contain a set of proprietary clauses which are edited version written by Knauf Insulation. alternatively, refer to NBS clause M21 Performance Compression resistance The rigidity of Rocksilk Krimpact Facade Slab makes it easy to handle and less prone to site damage than less robust options. The compression resistance of the Rocksilk Krimpact Facade Slab behind the lath and render will offer an excellent support to the lath and assist in the resistance of impact damage, helping to prolong its service life. Thermal performance Rocksilk Krimpact Facade Slab has a thermal conductivity of 0.037 W/mK. Table 54 gives U-values for a range of solid wall constructions. Fire performance Rocksilk Krimpact Facade Slab is non combustible and classified as Euroclass A1 to BS EN ISO 13501-1. Due to the insulation being non-combustible, cavity fire barriers are not required. For information on EJOT fixings, telephone 01977 687040 Er01 Table 54: Typical U-values of external walls insulated externally Insulation thickness (mm) Dense block and cast aggregate U-values (W/m 2 K) for 215mm solid masonry wall of: Medium block Lightweight aggregate Standard aircrete Lightweight aircrete Brick (λ=1.13) (λ= 0.51) (λ=0.34) (λ=0.16) (λ=0.11) (λ=0.77) 200 0.17 0.16 0.16 0.14 0.14 0.16 190 0.17 0.17 0.16 0.15 0.14 0.17 180 0.18 0.18 0.17 0.16 0.15 0.18 170 0.19 0.18 0.18 0.16 0.15 0.19 160 0.20 0.19 0.19 0.17 0.16 0.20 0.21 0.21 0.20 0.18 0.17 0.21 140 0.23 0.22 0.21 0.19 0.17 0.22 130 0.24 0.23 0.22 0.20 0.18 0.24 120 0.26 0.25 0.24 0.21 0.19 0.25 110 0.28 0.26 0.25 0.22 0.22 0.27 0.30 0.28 0.27 0.24 0.23 0.29 90 0.33 0.31 0.29 0.25 0.24 0.32 75 0.38 0.35 0.33 0.28 0.27 0.37 Note: Fixings assumed to be plastic insulation holders with 5mm dia. steel expansion pin. The U-values have been calculated to BS EN ISO 6946: 1997 and BR 443. For project specific calculations contact our Technical Advisory Centre on 01744 766666. 603

6.2.4 Design details: Render and clad walls Render and clad walls Insulation behind cladding Advantages Er03 Er04 3 Insulation slabs friction fit to the sides of the studs stopping cold air penetrating the insulation layer 3 Joints between the slabs knit together preventing cold bridging 3 Non-combustible insulation requires no cavity barriers, making installation quick and simple 3 Earthwool and Rocksilk Products are Zero GWP and Zero ODP insulation materials. 3 The Manufacture of Earthwool and Rocksilk products has a very low impact on the environment Single layer battens 3 Quick and simple installation Double layer battens 3 Permits greater insulation thickness Face-off battens 3 Insulation layer unbridged by timber battens Blockwork wall Earthwool Universal Slab CS24 or Earthwool Universal Slab RS45 between timber battens in two layers, with battens at right angles A vapour permeable layer Outer cladding (several options) Products Earthwool Universal Slab CS24 is a semi-rigid slab of non-combustible, glass mineral wool. Its manufacture has a very low impact on the environment and is classified as Zero ODP and Zero GWP*. Earthwool Universal Slab RS60 and RS45 are semi-rigid slabs of rock mineral wool. Their manufacture has a very low impact on the environment and is classified as Zero ODP and Zero GWP*. * Ecohomes and Code for Sustainable Homes classification Typical construction A solid masonry or concrete wall with insulation fixed to the outer face and overclad with tile hanging, timber boarding, terracotta tiles etc. The insulation can be fixed in three ways: Timber battens screwed and plugged to the blockwork and infilled with Earthwool Universal Slab CS24 or Earthwool Universal Slab RS45. Timber battens screwed and plugged to the blockwork and infilled with Earthwool Universal Slab CS24 or Earthwool Universal Slab RS45, with second layer of battens at right angles also filled with Earthwool Universal Slab CS24 or Earthwool Universal Slab RS45 (as shown above). This makes it practicable fix a greater overall thickness of insulation to the wall. Earthwool Universal Slab RS60 slab fixed directly to blockwork with insulation fixings, a vapour permeable membrane stapled to insulation and timber battens plugged and screwed to blockwork with spacer screws, such as Fischer type ASL. Installation Single layer battens Plug and screw timber battens (e.g. 75x50mm) to the brickwork at 600mm centres. Friction fit Earthwool Universal Slab CS24 or Earthwool Universal Slab RS45 between the battens. Staple a vapour permeable membrane to the battens. Fix the specified cladding system using the timber battens as the structural support. Double layer battens Plug and screw timber battens (e.g. 50x50mm) to the brickwork at 600mm centres. Friction fit Earthwool Universal Slab CS24 or Earthwool Universal Slab RS45 between the battens. Nail or screw a second layer of timber battens (e.g. 50x50mm) at right angles to the first and friction fit Earthwool Universal Slab CS24 or Earthwool Universal Slab RS45 between the battens. Staple a vapour permeable membrane to the battens. Fix the specified cladding system using the timber battens as the structural support. 604

Design details: Render and clad walls 6.2.4 Typical detail at window opening Typical specification Earthwool Universal Slab CS24*/ Earthwool Universal Slab RS45*...mm thick to be friction fitted between timber battens. (*Delete as appropriate) A vapour permeable membrane to lap flashing at window head The insulation should be close butted and cut as necessary so there are no gaps in the insulation layer. Once the insulation is firmly in place unroll a vapour permeable membrane horizontally across the wall and staple to the timber battens at maximum 500mm centres. Horizontal joints to be lapped mm, vertical joints to be lapped mm and staggered. Alternatively, refer to NBS clause P10/210. Gaps around window frame filled with expanding foam to minimise air leakage Flexible sealant at plaster/sill junction and sill/window frame junction to minimise air leakage Earthwool Universal Slab RS60...mm thick to be fixed to masonry wall with insulation supports fixings, two per slab. The insulation should be close butted and cut as necessary so there are no gaps in the insulation layer. Once the insulation is firmly in place unroll a vapour permeable membrane horizontally across the wall and staple to the insulation. Horizontal joints to be lapped mm, vertical joints to be lapped mm and staggered. Fix timber battens through the breather membrane and insulation at centres to suit the cladding with spacer fixings. Face-off battens Table 55: Typical U-values for solid walls with insulation behind cladding on a solid masonry wall Fix Earthwool Universal Slab RS60 in broken U-values (W/m 2 K) for 215mm solid masonry wall of: bond against the wall using plastic insulation Insulation Dense Medium Lightweight Standard Lightweight Brick supports, such as Fischer type DHK. Usually thickness block block aggregate aircrete aircrete two supports per slab are sufficient. (mm) Staple a vapour permeable membrane (λ=1.13) (λ= 0.51) (λ=0.34) (λ=0.16) (λ=0.11) (λ=0.77) to the Earthwool Universal Slab RS60. Earthwool Universal Slab CS24 (with insulation between 50mm wide timber studs at 600mm Fix timber battens through the insulation into the centres) masonry substrate using spacer screws, such as 0.33 0.31 0.29 0.25 0.22 0.31 Fischer type ASL. Use the spacer screws, as per Er03 75 0.41 0.38 0.35 0.29 0.26 0.38 manufacturer instructions, to fix the batten off the face of the wall, to the depth of the 80 0.54 0.48 0.44 0.36 0.31 0.50 insulation so the battens are tight to the face of Earthwool Universal Slab CS24 (with insulation between 50mm wide timber studs in two layers) the insulation, but not compressing it. The +50 0.23 0.22 0.21 0.19 0.18 0.22 position and lateral spacing of the battens will Er03 75+50 0.27 0.25 0.24 0.21 0.20 0.26 depend on the type of cladding specified. 80+50 0.32 0.30 0.29 0.25 0.22 0.31 Performance Earthwool Universal Slab RS60 (with timber battens fixed using 8mm dia. spacer screws) Thermal performance 700 0.29 0.27 0.26 0.23 0.21 0.27 Earthwool Universal Slab CS24, Earthwool Er04 Universal Slab RS45/60 have a thermal 75 0.36 0.33 0.32 0.27 0.24 0.34 conductivity of 0.035 W/mK. 60 0.43 0.39 0.36 0.30 0.27 0.39 Table 55 gives U-values for a range of solid 50 0.48 0.44 0.41 0.33 0.29 0.44 wall constructions. Note: The U-values have been calculated to BS EN ISO 6946: 1997 and BR 443 and assume an internal finish Fire performance of 12.5mm plasterboard on dabs. Earthwool Universal Slab CS24 and Earthwool Universal Slab RS45/60 are classified as Euroclass A1 to BS EN ISO 13501-1. 605

6.2.4 Design details: Render and clad walls Render and clad walls Rainscreen cladding Advantages Er05 3 Slabs knit together preventing cold bridging at joints 3 Lightweight slab easy to cut and fit Substructure 3 Non-combustible fire safe product 3 Friction fit behind and between cladding rails Fixing bracket 3 Water repellent slab 3 Earthwool Products are Zero GWP and Zero ODP insulation materials 3 The manufacture of Earthwool products has a very low impact on the environment Earthwool RainScreen Slab Support rail Rainscreen panel Products Earthwool RainScreen Slab is a rock mineral wool slab containing a water repellent additive, specially developed for rainscreen cladding applications. Its manufacture has a very low impact on the environment and is classified as Zero ODP and Zero GWP* * Ecohomes and Code for Sustainable Homes classification Typical construction Rainscreen systems comprise outer cladding panels that are bolted to a supporting framework of rails, which are supported by brackets fixed through a thermal break pad back to the building frame. A layer of insulation is fixed independently against the building substructure using proprietary insulation fasteners. Earthwool RainScreen Slab is recommended for this application, as it is lightweight but rigid enough to resist the compression forces generated when installing the insulation slabs to the masonry substrate. Installation Earthwool RainScreen Slab is positioned between the support brackets for the rainscreen cladding and across the whole area to be insulated. Cut the slabs with a sharp knife to fit around the brackets so there are no gaps in the insulation. To minimise thermal bridging, the brackets should be of sufficient depth to allow the panel support rails to be located clear of the face of the insulation. The insulation should be close butted and fixed independently against the building substructure using proprietary insulation fasteners in accordance with the design specification. Once the insulation is firmly in place, the application of the cladding can proceed. Ensure that a ventilated cavity remains between the insulation and the external cladding. The dimensions of the ventilated cavity should not exceed the limits in the Building Regulations. Fixing Earthwool RainScreen Slab to concrete wall 606

Design details: Render and clad walls 6.2.4 Typical junction detail with exposed floor Earthwool RainScreen Slab Proprietary rainscreen cladding system Support brackets for vertical rails Continuous ribbon of adhesive behind plasterboard and flexible sealant below skirting to minimise air leakage Typical specification Earthwool RainScreen Slab...mm thick to be fixed independently against the building substructure using proprietary insulation fasteners in accordance with the design specification. The insulation should be close butted and fitted around all adjacent parts of the rainscreen support brackets to minimise any thermal bridging. Once the insulation is firmly in place the application of the rainscreen cladding can proceed. Alternatively, refer to NBS clause H92/776. Continuity between wall and exposed floor insulation to avoid thermal bridge Earthwool Soffit Linerboard Table 56: Typical U-values of external walls with rainscreen cladding U-values (W/m 2 K) for 215mm solid masonry wall of: Insulation thickness (mm) Dense block Medium block Cast concrete aggregate (λ=1.13) (λ= 0.51) (λ=0.13) 200 0.24 0.23 0.24 190 0.25 0.24 0.25 180 0.26 0.25 0.26 170 0.27 0.26 0.27 160 0.28 0.27 0.28 0.29 0.28 0.29 140 0.31 0.29 0.31 130 0.32 0.32 0.32 120 0.34 0.33 0.34 Note: Fixings assumed to be plastic insulation holders with 5mm dia. steel expansion pin. The U-values have been calculated to BS EN ISO 10211 and BR 443. For project specific calculations contact our Technical Advisory Centre on 01744 766666. Table 57: Masonry fixings for Earthwool RainScreen slab Fixing to Masonry Performance Thermal performance Earthwool RainScreen Slab has a thermal conductivity of 0.035 W/mK. The U-value of a proprietary rainscreen cladding system is dependent on the degree of thermal bridging in the system. Typically 110-120mm of Earthwool RainScreen Slab will achieve a U-value of 0.35 W/m 2 K, but Knauf Insulation advise consulting individual rainscreen cladding manufacturers for U-values appropriate for their system. The Knauf Technical Advisory Centre is able to provide numerically calculated U-values to support specifications for the installation of Earthwool RainScreen Slab. Fire performance Earthwool RainScreen Slab is classified as Euroclass A1 to BS EN ISO 13501-1. Product thickness (mm) EJOT Code Fastener location on the board: perimeter centre 170 TID 215+VT 90 washer TID-MR 250+TID TR 80mm washer 160 TID 195+VT 90 washer TID-MR 250+TID TR 80mm washer TID 195+VT 90 washer TID-MR 200+TID TR 80mm washer 140 DH 8 x 160 TID-MR 200+TID TR 80mm washer 130 DH 8 x 160 TID-MR 200+TID TR 80mm washer 120 DH 8 x 140 TID-MR 170+TID TR 80mm washer 607

6.2.4 Design details: Render and clad walls Render and clad walls Curtain walling Advantages 3 Earthwool Universal Slabs RS45/60 are easy to cut and fit 3 Non-combustible fire safe product 3 Readily available products Er06 Plasterboard inner lining Earthwool Universal Slab RS45 or RS60 3 Earthwool Universal Slabs RS45/60 are Zero GWP and Zero ODP insulation materials 3 The manufacture of Earthwool Universal Slab RS45/60 has a very low impact on the environment Panel structure Stone facing to panel Products Earthwool Universal Slab RS45/RS60 are semi-rigid slabs of rock mineral wool. Their manufacture has a very low impact on the environment and is classified as Zero ODP and Zero GWP* * Ecohomes and Code for Sustainable Homes classification Typical construction Curtain walling systems come in several forms. The illustration above shows a unitised curtain wall system. Unitised curtain wall facades are suitable for various facing materials such as aluminium, steel, natural stone or glass. They are assembled in a factory as large integral units, and taken to site for fast track fixing. Earthwool Universal Slab RS45/RS60 are recommended for insulating curtain walling systems. Installation Earthwool Universal Slab RS45/RS60 are cut to size and installed in the factory as the middle layer of a pre-assembled curtain wall unit. The panels are typically hung onto and/or mechanically fixed to the building's superstructure Performance Thermal performance Earthwool Universal Slab RS45/RS60 have a thermal conductivity of 0.035 W/mK. The U-values for proprietary curtain walling systems are dependent on the degree of thermal bridging in the system. Typically mm of Earthwool Universal Slab RS45/RS60 is required to achieve a U-value of 0.35 W/m 2 K, but Knauf Insulation advise consulting individual curtain walling manufacturers for U-values appropriate for their system. Fire performance Earthwool Universal Slab RS45/RS60 are classified as Euroclass A1 to BS EN ISO 13501-1. 608

Design details: Render and clad walls 6.2.4 Unitised curtain walling corner panels being assembled in the factory. Typical specification Earthwool Universal Slab RS45*/RS60*... mm thick to be housed within the opaque modular panels as part of the proprietary curtain wall system specified in clause... of the specification. (*Delete as appropriate.) Alternatively, refer to NBS clause H11/780. 609

Knauf Insulation Ltd PO Box 10 Stafford Road St Helens Merseyside WA10 3NS UK Tel: 01744 766 600 Fax: 01744 766 750 www.knaufinsulation.co.uk Ref: KB140610 June 2010 Knauf Insulation Ltd Customer Service (Sales) Technical Advisory Centre Literature PO Box 10 Tel: 0844 800 0135 Tel: 01744 766 666 Tel: 08700 668 660 Stafford Road Fax: 01744 612007 Fax: 01744 766 667 Fax: 0870 400 5797 St Helens Email: sales@knaufinsulation.com Email: tech@knaufinsulation.com Email: info@knaufinsulation.com Merseyside www.knaufinsulation.co.uk WA10 3NS