Isover Installation GuideInstalling External Timber Frame Wall Insulation
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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.
Isover Technical Advice Our dedicated technical support team can provide guidance with regulation compliance, product installation and product performance.
Tel: 0115 945 1143 E-mail: [email protected]
About Saint-Gobain Isover
The importance of correct installationThe purpose of this guide is to provide technical guidance for installing Isover insulation into timber frame walls. Quality and accuracy of installation is vitally important if a dwelling’s actual performance is going to meet its designed targets.
Poorly installed insulation not only creates an energy inefficient building with uncomfortable draughts but can also lead to cold spots on the internal leaf leading to condensation problems.
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Insulating external timber frame walls
Environmental credentialsAt Isover we take our environmental responsibility seriously. The very nature of our business is to develop insulation solutions to protect both your built environment and the natural environment. That is why we have developed our 3 point plan for environmental sustainability. This dynamic plan focuses our efforts on continuously improving the way in which our products and processes impact your environment and seeks to ensure that Isover use less materials, less energy and are responsible for fewer emissions.
✯ Less materials ✯ Less energy ✯ Less emissions
Benefits of using Isover insulation
Why use Isover’s full-fill glass mineral wool solution?
The inherent properties of Isover products enable our solutions to provide insulation for three key aspects of the built environment:
ThermalIsover offers energy efficient thermal solutions to meet and exceed even the most demanding requirements.
AcousticIsover solutions provide a comfortable living environment, protecting inhabitants from exterior noise such as road traffic, trains and aeroplanes.
Fire & SafetyIsover insulation is totally non-combustible and fire safe to protect your most precious resource and provide a safer building environment.
UK Timber Frame AssociationIsover is a member of the UKTFA, working with the association and its members to highlight the benefits of timber frame constructions and promote best practice within the industry.
Therm
al insulation
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Isover Timber Frame Batts and Rolls
Step 1Install in a clean, dry environment. Ventilate the area if possible and wear appropriate personal protective equipment.
Step 2Remove insulation from packaging. Only remove rolls from packs as required to enable easy storage of any remaining product.
Step 3If cutting is required use a clean, sharp knife to trim insulation. Cut panels a minimum of 10mm larger than the actual panel size. Do not over trim as the insulation needs to fully-fill studs to ensure maximum performance.
Step 4Isover Timber Frame Batts and Rolls are friction fitted and can simply be pushed into place. No additional fixings are required.
Step 5Batts must be tightly butted together with no visible gaps.
Step 6Any visible gaps must be fully-filled to provide maximum thermal and acoustic performance.
Procedure
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Insulating external timber frame walls
Isover Frame Façade Slab With masonry outer leaf
Step 1Always install Isover Frame Façade Slab with tongue and groove joints running vertically.
Step 2Fix the insulation to the timber frame structure using Isover thermal break wall ties and large headed galvanised clout nails at maximum centres of 600mm vertical and horizontal. Hammer the nail through the insulation and into the timber until the flat surface of the wall tie meets the insulation.
Step 3Cut the insulation using a sharp saw and straight edge. At window and door reveals, ensure the insulation is fitted as close to the reveal as possible to prevent gaps in the insulation layer.
Step 4Ensure the insulation is tightly butted and seal the joints with Isover sealing tape to ensure the building is weathertight.
Step 5Build up the masonry leaf ensuring a 50mm cavity is maintained between insulation and outer leaf. Twist the Isover wall tie to manoeuvre it in line with mortar joints.
Procedure
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Isover Frame Façade Slab With timber clad / tile hung finish
Step 1Always install Isover Frame Façade Slab with tongue and groove joints running vertically.
Step 2Fix the insulation to the timber frame structure using Isover spacers and large headed galvanised clout nails at maximum centres of 600mm vertical and horizontal. Hammer the nail through the insulation and into the timber until the feet of the spacer reach the surface of the timber.
Step 3Cut the insulation using a sharp saw and straight edge. At window and door reveals, ensure the insulation is fitted as close to the reveal as possible to prevent gaps in the insulation layer.
Step 4Ensure the insulation is tightly butted and seal the joints with Isover sealing tape to ensure the building is weathertight.
Step 5Treated timber counter-battens are fixed over the spacers at 600mm centres to coincide with the timber studs. The timber clad system is then fixed to the timber counter-battens.
Procedure
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Insulating external timber frame walls
Isover Vario Membrane System
Site preparationThe site must be clean and dust free to ensure optimum adhesion of tapes and sealants. Contamination with site dust will affect the adhesion of the tape and sealant and affect the airtightness results.
Step 1Loosen and clean masonry dust with a brush. If the walls are made of sandy texture and cannot be cleaned with a brush, then a primer can be used to bond the sand particles together to allow the tapes / sealant to form a good airtight seal.
Step 2For timber preparation remove all loose and dirty timber particles with a brush. All areas must be vacuumed thoroughly before applying any tape or sealant.
Membrane installation
Step 1Isover Vario KM Duplex membrane is rolled out either horizontally or vertically and stapled to the timber studs. The membrane must be installed with the shiny side facing the installer. Staples should be a minimum of 10mm wide and 8mm long and should be situated no more than 150mm apart.
Procedure
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Step 2The membrane must be installed with a minimum 100mm overlap between membrane joints. The 100mm square pattern on the membrane can be used to create this overlap without a requirement for measuring.
Step 3Seal joints between the membranes using the KB1 tape ensuring the tape completely seals the overlap. It is important that Vario is NOT stretched or sealed under loading, as this will damage the performance of the membrane over time.
Overlaps with solid structures
Step 1Where Isover Vario membrane overlaps with solid structures use DS sealant to ensure airtightness.
Step 2When using DS sealant do not flatten the mastic bead under the membrane, place the membrane onto the DS sealant and then run forefingers up either side of the sealant creating a pinched ridge of mastic under the membrane.
Step 3Add a further seal with Isover Multitape to ensure complete airtightness.
Procedure
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Insulating external timber frame walls
Sealing corners
Step 1Corners can be easily sealed using Isover Multitape.
Step 2Cut the tape halfway towards the centre and remove the backing from the cut section side only.
Step 3Fold the tape at a right angle, bend the cut halves over and seal together to create a corner section.
Sealing around beams and posts
Step 1Where beams penetrate the Isover Vario membrane it is necessary to use Isover DS sealant and tape to repair the surrounding area.
Step 2Before applying Isover Vario membrane use Isover Multitape around the edges of the post.
Procedure
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Step 3Seal all corners of the post with Isover DS sealant and add extra Isover Multitape at each corner to ensure complete airtightness.
Sealing around services
Step 1Cut the Isover Vario membrane as closely as possible around any services (pipes / ducts etc).
Step 2To complete the airtight seal around the service use a membrane offcut. Wrap it around the service, securing with Isover KB1 tape, ensuring that there is an overlap of at least 1 square.
Step 3Cut narrow strips approximately 2cm wide x 5cm long.
Procedure
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Insulating external timber frame walls
Step 4Fan the narrow strips out and flatten against a smooth surface.
Step 5Apply a thin bead of DS sealant all the way around the base of the template.
Step 6Using another piece of membrane offcut, cut a hole in the centre with a radius approximately 2mm less than that of the service. The membrane is slightly elastic and will stretch over the service to create a tight fit.
Step 7Apply gentle force to create a joint between the two pieces of membrane and DS sealant. Allow the DS sealant to curve slightly before removing and positioning the finished template over the service. Seal the joint using KBI tape.
Sealing around wires
Step 1
Make a hole for the cables by pushing a ball point pen through the Isover Vario membrane and feed the cable through the hole.
Procedure
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Procedure
Step 2Create an airtight seal around the hole using tape and Isover DS sealant.
Sealing around windows
Step 1Cover the window frame with Isover Vario membrane as if it were a flat wall, ignoring the window.
Step 2Cut an “H” shape into the membrane.
Step 3Use Isover Vario tape to seal the upper and lower flaps to the frame of the window.
Step 4
Use two separate strips of Isover Vario membrane and use DS sealant and / or Isover Multitape to create an airtight join to the window frame. Ensure all membrane joins are sealed with tape.
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Insulating external timber frame walls
Isover Timber Frame BattA glass mineral wool batt providing thermal and acoustic insulation for timber walls and roofs to help meet Approved Document L (England and Wales) and Section 6 (Scotland).
Product Thickness (mm)
Width (mm)
Length (mm)
Batts per pack
Pack area (m²)
Isover Timber Frame Batt 32 90 570 1175 5 3.35
Isover Timber Frame Batt 32 140 570 1175 5 3.35
Isover Timber Frame Batt 35 90 570 1175 10 6.70
Isover Timber Frame Batt 35 140 570 1175 6 4.02
Isover Timber Frame Batt 40 90 570 1175 14 9.38
Isover Timber Frame Batt 40 140 570 1175 8 5.36
Isover Timber Frame Batt 43 90 570 1175 12 8.04
Isover Timber Frame Batt 43 140 570 1175 8 5.36
Therm
al insulation ✔ Thermal conductivity of 0.032 to 0.043W/mK within the range.
Helps to meet the requirements of Approved Document L 2010 (England & Wales) and Section 6 (Scotland).
✔ Easy to install Push fits between 600mm timber
stud centres with no need for additional fixings. Two batts end-to-end typically fit standard storey height.
✔ Euroclass A1 fire rating Totally non-combustible and fire
safe.
✔ Water resistant Resilient to moisture damage in
storage, during transportation and on-site during installation.
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Product Thickness (mm)
Width (mm)
Length (mm)
Pack area (m²)
Isover Timber Frame Roll 35 90 2 x 570 5300 6.04
Isover Timber Frame Roll 35 140 2 x 570 4000 4.56
Isover Timber Frame Roll 40 90 2 x 570 10130 11.55
Isover Timber Frame Roll 40 140 2 x 570 6500 7.41
Isover Timber Frame RollA glass mineral wool roll providing thermal and acoustic insulation for timber walls to help meet Approved Document L (England and Wales) and Section 6 (Scotland).
Therm
al insulation ✔Thermal conductivity of 0.035 to 0.040W/mK within the range
Helps to meet the requirements of Approved Document L 2010 (England & Wales) and Section 6 (Scotland).
✔Easy to install Push fits between 600mm timber
stud centres with no need for additional fixings.
✔ Euroclass A1 fire rating Totally non-combustible and fire
safe.
✔ Water resistant Resilient to moisture damage in
storage, during transportation and on-site during installation.
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Insulating external timber frame walls
Product Thickness (mm)
Thermal conductivity (W/mK)
Thermal resistance (m²K/W)
Width (mm)
Length (mm)
Batts per pack
Pack area (m2)
Isover Frame Façade Slab
50 0.031 1.61 1200 1800 4 8.64
Product Units Measure
Thermal Break Wall Tie 1 box 250 ties
Spacer 1 box 250 spacers
Sealing Tape 1 box (12 rolls) 50m per roll
Isover Frame Façade SlabA low lambda rigid glass mineral wool slab providing a continuous layer of insulation to the exterior of the timber frame construction.
Therm
al insulation ✔ Thermal conductivity of 0.031W/mK
Helps to meet and exceed the requirements of Approved Document L 2010 (England & Wales) and Section 6 (Scotland).
✔ Reduces cold bridging Achieve continuous layer of
insulation reduces cold bridging through the frame enabling U-values down to zero carbon levels.
✔ Weatherproof breathable facing Protects the construction and negates the
need for an additional breather membrane.
✔ Tongue and groove vertical joints To aid installation and minimise air gaps
between insulation.
✔ Full range of accessories available Including wall-ties, spacers and sealing tape.
✔ Euroclass A2 fire rating Totally non-combustible and fire safe.
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Isover Vario Membrane SystemA high performance membrane unique in providing excellent levels of airtightness with unparalleled protection against moisture.
Product Units Measure
Isover Vario KM Duplex Membrane 1 roll (60m²) 40m x 1.5m
Isover Vario Multitape 1 box (10 rolls) 25m
Isover Vario KB1 1 box (5 rolls) 40m
Isover Vario DS Sealant 1 box (12 cartridges) 310ml cartridges
✔ Improves the energy efficiency of the building Reduces heat loss through the building
envelope by reducing air leakage.
✔ Improves thermal comfort Protects against leaky cracks and joints
which invariably cause uncomfortable drafts.
✔ Enables designers to comply with SAP And other standard assessments for whole
building performance through air tightness.
✔ Ideal for use in low energy constructions Including Passivhaus constructions and
buildings with mechanical ventilation and heat recovery systems.
✔ Intelligent moisture management properties Help to protect the building fabric from
moisture damage, reducing possible mould growth or fabric degradation.
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Insulating external timber frame walls
✔ Provides up to 100 minutes fire protection in concealed cavities
Helps to meet requirements of Approved Document B (England & Wales) and Section 2 (Scotland).
✔ Improves building acoustics Helps minimise flanking sound transmission
along concealed wall cavity.
✔ Excellent compression qualities Allows for the barrier to be easily
installed into cavities without risking damage to brickwork.
✔ Storey height solution Fewer joints means less chance of
installer error on-site and a reduction in installation time.
✔ Colour coded packaging Avoids installation of the incorrect
barrier sizes on-site.
Isover Cavity BarriersA non-combustible glass wool cavity barrier used to restrict the spread of smoke and flames and to minimise flanking noise transmission in concealed cavities.
Product Cavity size (mm)
Length (mm)
Width (mm)
Sleeve colour
Isover Cavity Barrier (65) 50-65 1200 100 Yellow
Isover Cavity Barrier (80) 66-80 1200 100 Blue
Isover Cavity Barrier (100) 81-100 1200 100 White
Isover Cavity Barrier (65) 50-65 1200 300 Yellow
Isover Cavity Barrier (80) 66-80 1200 300 Blue
Isover Cavity Barrier (100) 81-100 1200 300 White
Isover Cavity Barrier (65) 50-65 2400 300 Yellow
Isover Cavity Barrier (80) 66-80 2400 300 Blue
Isover Cavity Barrier (100) 81-100 2400 300 White
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Published Date: July 2014
Isover Document Reference: ETFW-SG-1401
Isover Order Placement or Order Enquiries: Tel: 0800 032 2555 Fax: 0800 917 9188
Buildings Insulation – Technical Enquiries Tel: 0115 945 1143 Email: [email protected]
Saint-Gobain Isover Gotham Road East Leake Loughborough Leicestershire LE12 6HX Tel: 0115 969 8010 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.