Isover Solutions Guide - External Masonry Cavity Walls

Isover Solutions GuideSpecifying External Masonry Cavity Wall Insulation

2 3www.isover.co.uk Isover Technical Advice – Tel: 0115 945 1143 Isover Technical Advice: [email protected] www.isover.co.uk

Achieving high levels of energy efficiency in external masonry cavity walls

As a world leader in designing, manufacturing and distributing building materials, Saint-Gobain is committed to providing innovative solutions to the most fundamental challenges facing the world today; reducing energy consumption, limiting our impact on the environment and creating a new generation of buildings which are safe, comfortable and energy efficient.

At Saint-Gobain Isover we develop sustainable insulation solutions to protect both your built environment and the natural environment. To maintain our focus we have placed environmental responsibility at the heart of our business strategy.

Our vision to lead the UK mineral wool market in energy efficiency and acoustic insulation solutions will be achieved with products that meet the highest thermal, acoustic and fire safety performance levels. We will meet changing regulations first and surpass current regulations for those that wish to excel. Our products will provide best value solutions for the residential, commercial, RMI and technical building environments, be safe to use and help to protect the environment.

The UK’s current housing stock is responsible for 30% of primary energy used in the UK and 27% of the UK’s CO2 emissions. Masonry construction currently accounts for 75% of all housing starts in the UK, therefore ensuring these constructions are energy efficient is vital if we are to achieve the commitment of the Climate Change Act to eliminate carbon emissions from our built environment by 2050.

At Saint-Gobain Isover we are committed to working jointly with today’s designers and contractors to meet these challenges, in making buildings of the future as energy efficient as possible.

Saint-Gobain one of the top 100 Industrial groups in the world and the global leaders in the construction market.

The UK is unique in being the only country around the world that has introduced a long-term legally binding framework to tackle the dangers of climate change.

Thermal conductivity as low as 0.032W/mKIsover insulation helps to meet the requirements of Approved Document L 2010 (England & Wales) and Section 6 (Scotland), whilst keeping wall thicknesses to a minimum.

Quick and easy on-site installation• Isover full-fill cavity wall insulation

solutions remove the requirement for retaining discs and cavity barriers.

• Isover insulation is manufactured from high quality glass mineral wool which makes it lightweight and easy to handle, cut and install.

Environmental leadershipIsover cavity wall insulation has excellent environmental credentials and helps towards valuable credits for the Code for Sustainable Homes.

• Isover cavity wall insulation achieves the highest BRE Global Green Guide online summary rating. See the Product Overviews on pages 13 and 14 for more information.

• Recycled content of up to 86%.• Zero Ozone Depletion Potential (ODP). • Global Warming Potential (GWP) of less

than 5.

Euroclass A1 fire ratingIsover cavity wall insulation is totally non-combustible and fire safe, achieving a Euroclass fire rating of A1.

Benefits of using Isover insulationAbout Saint-Gobain Isover

Excellent thermal performance coupled with unrivalled environmental credentials – Isover insulation offers a complete energy efficient solution for external masonry cavity walls.

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Building regulations & standards

Approved Document L 2010Compliance is based on the carbon performance of the whole dwelling, a measure of which is given through the use of the Standard Assessment Procedure (SAP calculation).

Compliance is no longer demonstrated by the elemental U-value method, but U-value calculations are required as they form part of the SAP calculation.

Although reference is made to ‘Design Limit’ U-values within Approved Document L, U-values better than the ‘Design Limit’ are likely to be required to meet the required target emission rate of the building.

External Walls Limiting fabric parameter (W/m2K) Isover recommended U-value (W/m2K)

New Build – Residential 0.30 < 0.28

New Build – Non-Residential 0.35 < 0.30

Section 6 – Scotland 2010The standards and guidance given in Section 6 2010 are intended to reduce emissions of carbon dioxide by approximately 30% compared to the 2007 standards. The key changes over the 2007 version are:• 30% improvement in CO2 emissions for new buildings• Expanded role for the use of low carbon equipment• Improved backstops for fabric U-values and service efficiencies for new buildings

Section 6 includes a range of measures which can be used in setting the target emission rate for a notional dwelling. Included are guideline “notional” U-values, as follows:

External Walls Limiting fabric parameter (W/m2K) Notional U-value (W/m2K)

New Build – Residential 0.25 0.19

New Build – Non-Residential 0.30 0.27

BBA approvalIsover CWS 36 and Isover CWS 32 are endorsed by the British Board of Agrément (BBA) for use in all exposure zones* for buildings up to and including 25m in height. • Isover CWS 36 – BBA Certificate 90/2465.• Isover CWS 32 – BBA Certificate 90/2465.To download a copy of the certificate visit www.bbacerts.co.uk

*Consult the BBA certificate for limitations

The Code for Sustainable HomesIsover products can be specified to achieve reduced CO2 target emission rates by means of insulation for improved U-values. Specialist products such as the Isover Vario Membrane System and expert design guidance can also help to achieve improved airtightness performance. For more information or to request a CPD, please call 0115 969 8010.

Passivhaus TrustIsover is a founding member of the Passivhaus Trust. The Passivhaus Trust is an independent non-profit organisation that willl provide leadership in the UK for adoption of the Passivhaus standard and methodology. Its aim is to promote the principles of Passivhaus as a highly effective way of reducing energy use and carbon emissions from buildings in the UK.For more information visit www.passivhaustrust.org.uk

✔ Reliable on-site performance• The flexible properties of Isover full-fill glass mineral wool allow the insulation to follow the uneven surface of

the cavity making it more effective at restricting air movement within the cavity and removing the risk of heat loss through convection.

• The thermal performance of Isover full-fill glass mineral wool is not reliant on the reflective properties of foil facings in low emissivity cavities, which can be compromised by dulling of the reflective surface caused by mortar dust and excessive air movement.

✔ Quick and easy on-site installation• No requirement for retaining discs on wall ties – Isover full-fill insulation negates the need for retaining discs

saving on material costs and installation time.

• No requirement for cavity fire barriers – Isover full-fill insulation helps minimise flanking sound transmission and prevents the spread of fire within the external wall cavity.

• Robust solution – Isover full-fill insulation is able to withstand the demands of on-site installation, improving in-situ performance and reducing on-site waste.

✔ Cost efficient solutionThe following example compares the installed cost of an Isover full-fill glass mineral wool solution and a partial fill system using a rigid foam board.

Isover solutions are 51% of the total cost of rigid foam alternatives

• Isover full-fill glass mineral wool solution 103mm brick, 100mm cavity fully-filled with Isover CWS 36, 100mm medium density block (0.51W/mK), 12.5mm plasterboard on dabs.

Component Unit Quantity Price Labour Installed cost Isover CWS 36 100mm m² 80 2.65 2.16 384.80Retaining discs on wall ties nr 0 0.07 0.03 0.00Closing cavities with cavity barriers m 0 8.84 2.01 0.00

Total Installed Cost 384.80• Rigid foam board partial fill solution 103mm brick, 100mm cavity partial-filled with 50mm Kingspan TW50, 100mm medium density block (0.51W/mK), 12.5mm plasterboard on dabs.

Component Unit Quantity Price Labour Installed cost Kingspan TW50 50mm m² 80 5.00 3.41 672.80Retaining discs on wall ties nr 240 0.07 0.03 24.00Closing cavities with cavity barriers m 5 8.84 2.01 54.25

Total Installed Cost 751.05

Note: Based on calculations in SPONS Architects and Builders Price Book 2011 for a 100mm cavity wall with medium density blocks and a U-value of 0.27W/m2K. Insulation costs based on an order of 1000m² from a national distributor at time of publication.

Why use Isover’s full-fill glass mineral wool solution over rigid foam board alternatives?



Full-fill masonry cavity wall – 75mm cavity

1 103mm brick 2 75mm cavity fully filled with Isover insulation

(see table below) 3 100mm block (see table below) 4 Gyproc plasterboard or Gyproc ThermaLine

laminate (see table below)

U-value W/m²K

Isover insulation (75mm) Block W/mK

Wall thickness (mm)

British Gypsum plasterboards

Isover CWS 36 between cavity

0.32 Isover CWS 36 0.15 301 12.5mm Gyproc WallBoard


Isover CWS 32 (0.032W/mK) between cavity



Isover CWS 32 (0.032W/mK) between cavity with Gyproc ThermaLine laminate

0.26 Isover CWS 32 0.11 310 22mm Gyproc ThermaLine basic


0.24 Isover CWS 32 0.11 315 27mm Gyproc ThermaLine plus



0.18 Isover CWS 32 0.11 338 50mm Gyproc ThermaLine super

Solution overviewSolutions overview

All constructions are designed to meet or exceed 2010 Approved Document L Building Regulations and Section 6 (Scotland) as low as Passivhaus standard. The table below provides a snapshot of the U-values that can be achieved by these solutions.

Approved Document L1A 2006

Constructions to meet =Approved Document L1A 2010

CfSH - Level 4

Low Carbon -

Passivhaus

External Wall Solutions (W/m2K) Full-fill masonry cavity wall 0.

35

0.34

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

0.13

0.12

0.11

0.10

75mm Cavity

85mm Cavity

100mm Cavity

125mm Cavity

150mm Cavity

200mm Cavity

U-value calculationAll U-value calculations published within this document have been calculated using the methods and conventions set out in BR 443 (Conventions for U-value calculations, BRE, 2006).

Constructions with cavities 100mm and below are calculated using wall ties at 2.5 per m² with a thermal conductivity of 17W/mK. Constructions with cavities above 100mm are calculated using wall ties at 2.5 per m² with a thermal conductivity of 0.7W/mK.

BRE Green Guide Global online ratingsFull-fill masonry cavity wall - 75mm (or 85, 100, 125, 150, 200mm) cavity corresponds to the BRE Green Guide online specification for wall type construction within category "external walls", sub-category "blockwork cavity wall", element type "Brick, Stone and Block Cavity Wall" ref:- Brickwork outer leaf, insulation, cellular dense blockwork inner leaf, cement:lime mortar, plaster, paint Ref 806170092 or Brickwork outer leaf, insulation, aircrete blockwork inner leaf, cement mortar, plaster, paint Ref 806170028 or Brickwork outer leaf, insulation, dense solid blockwork inner leaf, cement mortar, plaster, paint Ref 806170027 which achieve a summary rating of A+ within Domestic, Health, Industrial, Commercial, Retail and education.

1

2

3

4

A+ Green Guide

NB: Alternative plasterboards from other manufacturers may be used. It is the responsibility of the specifier to ensure equivalent performance.

Please refer to page 6 for the full BRE green guide construction rating specification.

A+







U-value W/m²K

Isover insulation (100mm)Block W/mK

Wall thickness (mm)
















Solution overview





U-value W/m²K


Wall thickness (mm)















0.17 Isover CWS 32 0.11 348 50mm Gyproc ThermaLine super

Solution overview

1

2

3

4

1

2

3

4

A+ Green Guide

NB: Alternative plasterboards from other manufacturers may be used. It is the responsibility of the specifier to ensure equivalent performance. NB: Alternative plasterboards from other manufacturers may be used. It is the responsibility of the specifier to ensure equivalent performance.



A+




1 103mm brick 2 150mm cavity fully filled with Isover

insulation (see table below) 3 100mm block (see table below) 4 Gyproc plasterboard or Gyproc ThermaLine


U-value calculations based on thermal efficient wall ties (0.7W/mK)

U-value W/m²K


Wall thickness (mm)
















Solution overview






U-value W/m²K


Wall thickness (mm)
















Solution overview

1

2

3

4

1

2

3

4

A+ Green Guide

NB: Alternative plasterboards from other manufacturers may be used. It is the responsibility of the specifier to ensure equivalent performance. NB: Alternative plasterboards from other manufacturers may be used. It is the responsibility of the specifier to ensure equivalent performance.



A+








U-value W/m²K

Isover insulation (2 x 100mm)

Block W/mK

Wall thickness (mm)
















Solution overview

1

2

3

4

NB: Alternative plasterboards from other manufacturers may be used. It is the responsibility of the specifier to ensure equivalent performance.


A+

Isover CWS 32A glass mineral wool full-fill cavity slab providing thermal performance in external masonry cavity walls to meet Approved Document L (England and Wales) and Section 6 (Scotland).

3 Enables U-values as low as 0.17W/m2K using a single thickness of insulation and standard plasterboard

3 Full-fill solution helps minimise flanking sound transmission along the wall cavity and removes the requirement for cavity fire barriers

3 BBA approved for use in masonry walls (England & Wales) Approved for use in severe exposure zones and in buildings up to and including 25m in height (Certification No: 90/2465)

Thermal InsulationThermal conductivity of 0.032 W/mK. Helps to meet the requirements of Approved Document L 2010 (England & Wales) and Section 6 (Scotland).

Quick and easy on-site installation• The 455mm wide slabs are compatible

with conventional wall tie spacing ensuring ease of installation.

• Isover CWS 32 insulation is manufactured from high quality glass mineral wool which makes it lightweight and easy to handle, cut and install.

Water resistantResilient to moisture damage in storage, during transportation and on-site during installation.

Euroclass A1 fire ratingTotally non-combustible and fire safe.

Environmental LeadershipExcellent environmental credentials and helps towards valuable credits for the Code for Sustainable Homes.• Isover CWS 32 corresponds to the generic

specification ‘Glass wool insulation’ – density 48kg/m³ ref 815320004 which achieves a summary rating of A+ within Domestic, Health, Industrial, Commercial, Retail, Education.

• Recycled content of up to 86%.• Zero Ozone Depletion Potential (ODP).• Global Warming Potential (GWP) of less

than 5.

ProductThickness (mm)

Thermal conductivity (W/mK)

Thermal resistance (m²K/W)

Width (mm)

Length (mm)

Batts per pack

Pack area (m²)

Isover CWS 32 50 0.032 1.56 455 1200 14 7.64

Isover CWS 32 65 0.032 2.03 455 1200 12 6.55

Isover CWS 32 75 0.032 2.34 455 1200 10 5.46

Isover CWS 32 85 0.032 2.66 455 1200 8 4.37

Isover CWS 32 100 0.032 3.13 455 1200 6 3.28

Isover CWS 32 125 0.032 3.91 455 1200 5 2.73

Isover CWS 32 150 0.032 4.69 455 1200 4 2.18

Product overview

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NB: Multiple layers of CWS 32 may be used in order to achieve the required thickness of insulation



Isover CWS 36A glass mineral wool full-fill cavity slab providing thermal performance in external masonry cavity walls to meet Approved Document L (England and Wales) and Section 6 (Scotland).

3 Full-fill solution helps minimise flanking sound transmission along the external wall cavity and removes the requirement for cavity fire barriers

3 Enables U-values as low as 0.19W/m2K using a single thickness of insulation and standard plasterboard

3 BBA approved for use in masonry walls (England & Wales). Approved for use in severe exposure zones and in buildings up to and including 25m in height (Certification No: 90/2465)

Product overview

Thermal InsulationThermal conductivity of 0.036W/mK. Helps to meet the requirements of Approved Document L 2010 (England & Wales) and Section 6 (Scotland).

Quick and easy on-site installation• The 455mm wide slabs are compatible

with conventional wall tie spacing ensuring ease of installation.

• Isover CWS 36 insulation is manufactured from high quality glass mineral wool which makes it lightweight and easy to handle, cut and install.

Water resistantResilient to moisture damage in storage, during transportation and on-site during installation.

Euroclass A1 fire ratingTotally non-combustible and fire safe.

Environmental LeadershipExcellent environmental credentials and helps towards valuable credits for the Code for Sustainable Homes.• Isover CWS 36 corresponds to the generic

specification ‘Glass wool insulation’ – density 24kg/m³ ref 815320002 which achieves a summary rating of A+ within Domestic, Health, Industrial, Commercial, Retail, Education.

• Recycled content of up to 86%.• Zero Ozone Depletion Potential (ODP). • Global Warming Potential (GWP) of less

than 5.

ProductThickness (mm)

Thermal conductivity (W/mK)

Thermal resistance (m²K/W)

Width (mm)

Length (mm)

Batts per pack

Pack area (m²)

Isover CWS 36 50 0.036 1.39 455 1200 20 10.92

Isover CWS 36 65 0.036 1.81 455 1200 16 8.74

Isover CWS 36 75 0.036 2.08 455 1200 16 8.74

Isover CWS 36 85 0.036 2.36 455 1200 12 6.55

Isover CWS 36 100 0.036 3.78 455 1200 12 6.55

Isover CWS 36 125 0.036 3.47 455 1200 8 4.37

Isover CWS 36 150 0.036 4.17 455 1200 6 3.28

NB: Multiple layers of CWS 32 may be used in order to achieve the required thickness of insulation

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Installation guide

Isover also publish an installation guide for external masonry cavity wall insulation. The objective of the guide is to support the industry with best practice guidance to achieve efficient installation with consistently high levels of on-site performance.

For more information or to order a copy of the guide please visit www.isover.co.uk

The guide includes:

3 Preparation details and generic guidance

3 A step-by-step guide to installing Isover external cavity wall insulation

3 An overview of Isover's external cavity wall products

FSC LOGO - PRINTER TO PLACE

www.3pointplan.co.uk www.isover.co.uk

Published Date: August 2013

Isover Document Reference: I-EMW-SG-1301

Isover Order Placement or Order Enquiries: Tel: 0800 032 2555 Fax: 0800 917 9188

Isover Technical Advice - Buildings Insulation: Technical Enquiries Tel: 0115 945 1143 Email: [email protected]

Isover UK Commercial Centre Gotham Business Park Leake Road Gotham Nottinghamshire NG11 0LB Tel: 0115 969 8010 Fax: 0115 983 1675 Email: [email protected]

Isover reserves the right to revise product specifications without notice. The information in this document was correct to the best of our knowledge at the time of publication. It is the users

responsibility to ensure that it remains current prior to use. The information in this document is for guidance only and should not be read in isolation. Users should read and familiarise

themselves with all the information contained in this document and ensure that they are fully conversant with the products and systems being used, before subsequent specification or

installation. For a comprehensive and up to date library of information visit the Isover website.

Documents

Isover Solutions Guide - External Masonry Cavity Walls