Icopal Monarperm Breathe One Breather Membrane

Monarperm Breathe One

Monarperm Breathe One utilises the latest technology to produce a durable and economical LR pitched roof breather membrane offering improved dependable performance in warm and cold ventilated and non-ventilated roofs with supported or unsupported construction.

Monarperm Breathe membranes are suitable for installation fully supported directly over insulation boards or draped unsupported over rafters and will be virtually unaffected by normal conditions within a pitched roof space.

Features & Benefits

  • ’Unrestricted’ use for wind uplift in UK & Ireland
  • Helps to avoid condensation risk in accordance with BS 5250
  • Highly Vapour Permeable
  • Completely Watertight & Airtight
  • Strong, Tough & Durable
  • BBA Certified
  • NHBC compliant.
  • Zone Suitability Map - Compliance with BS5534:2014 annex A

    The code of practice BS5534:2014 annex A requires that pitched roof underlays are assessed with regard to resisting the effects of wind uplift acting on the membrane.

    The code requires that manufacturers test their products at defined batten centres from 345mm for most interlocking tiles down to 250mm which covers most double lap and interlocking slates and against various levels of wind speed. This is to avoid “ballooning” which can impact upon the slates or tiles causing them to dislodge.

    Subject to the independent testing by official bodies, membranes are provided with a zonal classification indicating which particular areas of the Country they may be used.

    Monarperm Breathe membranes have been tested in accordance with BS5534 annexe A by the BRE and independently assessed and approved by the BBA.

    Zonal Suitability - Monarperm Breathe One (no tape required)

       
    Up to 345mm batten gauge
    Up to 250mm batten gauge
    Up to 250mm batten gauge
    Up to 250mm batten gauge
    Up to 250mm batten gauge
       
       
       
       
       

    The map above and tables below provide the wind uplift resistance data and the Zonal classification for Monarperm Breathe One Membranes.

    Rafter Spacing 600mm Monarperm Breathe One
    Batten Spacing Pa Zones
    < 345mm 944 1
    < 250mm 1834 1 - 5

     

    The above values are for overlaps made under a batten without the use of tape 

    Wind Zone 1 2 3 4 5
    Design Wind Pressure Pa 1600 1330 1150 975  820

     

    Note: Values stated in the above table relate to the required design pressures using batten centres of 345mm and where a well - sealed ceiling is installed, ridge height is not greater than 15m, roof pitch is between 12.5 & 70 degrees, site altitude is not greater than 100m and no significant topography is present.

    In other conditions the following values must be observed.

    • 1900 N/m² when no ceiling or no well - sealed ceiling is present
    • 2350 N/m² when no ceiling or no well-sealed ceiling is present and a permanent dominant opening is present on an external face of the building.

    As stated in BS5534:2014 membranes tested and suitable for use in Zone 1 at maximum 250mm batten spacing are suitable for use in all wind zones when fully supported by sarking boards, Plywood or Thermal Insulation.

  • Product Availability

     

    Product Code Description Roll Size Roll Weight
    3102823 Monarperm Breathe One 1m x 50m 5.0kg
    3102822 Monarperm Breathe One 1.5m x 50m 7.5kg

     

    Packaging

    Rolls are supplied individually packaged in a polythene outer bag which carries the Product description CE marking and zonal classification.

    Rolls per pallet: 30

    Storage

    Monarperm Breathe membranes should be stored on a clean and level surface, kept dry and adequately protected from damage.

  • Product Data and Performance

     

    Product Data:
    Composition: A three layer composite structure manufactured from a highly vapour open film bonded between two layers of non woven micro porous polypropylene.
    Colour: Blue upper surface
    White lower surface
    Rolls per pallet: 30

    Physical Properties

    Value

    Tolerance
    Weight: 95 g/m² +/- 10%
    Thickness: 0.43mm  
    Water vapour Transmission (Sd),m: 0.02 +0.03/-0.01
    Watertightness class: W1  
    Hydrostatic head (m): 5.85  
    Tensile Strength (N/50mm) unaged: 220 MD, 110 TD +40/-40
    Nail Tear Stength (N) 100 MD, 100 TD +20/-20
    Elongation (%) unaged: 80 MD, 90 TD +20/-25
    Low Temperature Flexibility deg C: -30  
    Wind Uplift: 0.944 kPa at 345 mm batten gauge and 600mm rafter centres
  • Installation

    Install Monarperm Breathe membranes in accordance with the following guidelines:

    • BS5534:2014, BS8000 part 6:2013, BS5250:2011 NHBC guidelines and Icopal fixing instructions.
    • Handle & Fix the membrane with care to ensure no tears or punctures prior to covering with the primary tiles or slates.
    • Counter battens or tile battens should be installed as soon as possible to fully secure the membrane and prevent unnecessary tearing by the wind action.
    • Cover the membrane as soon as possible with the outer covering of slates or tiles, Monarperm Breathe membranes will provide temporary protection but cannot be considered totally watertight.
    • When installing unsupported ie over open rafters ensure an adequate drape of 10 -15mm to ensure free draining of any water effectively to the eaves. Do not pull the membrane taught so that it is in contact with the tile batten as this will prevent the flow of water. Install by unrolling across the roof parallel to the eaves, working from eaves to ridge.
    • When joining rolls ensure a minimum 100mm overlap and secure with Monobond tape. Always join rolls over a rafter.

     

    Roof Pitch Horizontal Lap Vertical Lap*
    Partially Supported Fully Supported
    12.5° - 14° 225mm 150mm 100mm
    15° 150mm 100mm 100mm
    > 34° 100mm 75mm 100mm

    * form vertical laps over rafters

     

    • Always use a separate Icopal Eaves Guard at gutters to provide additional protection from UV exposure.
    • Do not lay any vapour permeable membrane over undried timber preservatives, water or solvent based.
    • Terminate the underlay at abutments by turning up 100mm behind securely fixed cover flashings and seal to the structure using Monobond tape.
    • Reinforcing strips of membrane should be installed at hips, valleys and ridges
    • Exposed fixing of the membrane should be avoided.
    • Use large head clout nails and avoid the use of staples.
    • Fixing should be made into the rafter along the top edge of the membrane and covered with the overlap of the adjacent sheet.
    • Fix the outer covering of slates or tiles in accordance with the manufacturers specific instructions and ensure the fixing specification complies with the relevant code of practice.
    • Ensure that any provision for ventilation complies with BS5250:2011 and NHBC guidelines section 7.2.S11.
    • Ensure the underlay does not obstruct any ventilation paths.
    • When detailing around services such as skylights and chimneys dress the underlay to the upstand min 100mm and seal with Monobond tape before covering with the appropriate counterflashing.

     

    Health and Safety

    Construction or replacement of a pitched roof means working at height and as such personal safety and prevention against a fall must be considered a priority. When working on a roof ensure all necessary safety precautions are in place and follow safe working practices. Although the Icopal Monarperm and MonarTile range are strong it should not be walked on or used as a working platform.

Contact Icopal 0161 8654444

Find Local Support

To discuss your project in more detail please contact
Your Local Area Manager

 

Technical Support

Telephone:

0330 123 4585

Email: technical.uk@bmigroup.com

 

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Email: sales.admin@bmigroup.com

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