Weather Defence

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Weather Defence 2ND Generation


Introducing our 2nd generation Weather Defence  - now better then ever before.  Originally launched in 2013, it is now used by 45% of AJ100 British Architects and 75% of top 20 main contractors.

A lightweight external gypsum sheathing board, it is 50% quicker to install than
cement particle board.
*Relates to product supplied from 1st September 2017

Weather Defence


Weather Defence is designed to be installed on: 

  • Light steel infill and oversail systems on concrete and steel frame buildings 
  • Modular Buildings 
  • Light Gauge Steel Frame Buildings 
  • Timber Frame Buildings

Edge Thickness Width Length Siniat Code
Square 12.5 mm 1200 mm 2400 mm 119967

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12 year warranty


  • Dimensionally stable, reliable airtightness
  • Quick and easy to cut (score and snap with a retractable knife) and install saving time and reducing costs
  • Water, weather and mould resistant, can now be left installed and exposed for up to 12 months on site before you need to complete the final cladding
  • No need for segregated cutting area, power tools or dust extractor 
  • Can eliminate the need for breather membrane saving time and reducing installation costs
  • Double BBA certified
  • 50% quicker to install and 30% lighter than cement particle board
  • Fully A1 non-combustible, compliant for structures above 18M
  • Fully recyclable gypsum core

Ask us for a CPD

Siniat is part of the RIBA CPD Providers Network and can contribute to your required 35 hours Continuous Professional Development.

Within 60 mins, you will gain a thorough overview of sheathing materials, and a more in-depth understanding of gypsum sheathing boards. A relatively new technology, gypsum sheathing has been used on over 350 projects across the country.

Register for our Gypsum External Sheathing CPD

siniat cpd gypsum external sheathing

Practical support from our technical experts

Technical support: On-site
Technical support - On-site

Browse here for information and contact details for all your technical queries.

Technical support: Logistics
Siniat offers a range of load size and options to suit all

We offer a range of load size options and vehicles to suit all types of delivery locations.

Click here for more information about vehicle types and delivery times.

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