Smoke shaft applications for Siniat shaftwall systems:

Approved Document B (Vols. 1 and 2) sets out requirements for smoke control through two methods: natural ventilation, and mechanical ventilation. The A1 Shaftwall System would generally be considered suitable for natural ventilation shaft applications, when correctly sealed. The A1 Shaftwall system would not be considered suitable for mechanical (including pressure differential) smoke control applications and tested ductwork should be used. Further detail is provided below for Vol 1.

Natural smoke ventilation in dwellings - Approved Document B Vol1 :

Design guidance on smoke shafts constructed for natural ventilation is provided in clauses 3.49-3.53, and 16.5-16.10; requirements for material reaction to fire of A1 to EN 13501-1 is provided in clauses 16.13-16.14. 

The Siniat A1 Shaftwall system is tested and classified to EN 1364-1 and EN 13501-2, and all significant materials are A1 reaction to fire to EN 13501-1, strength and sound insulation are also assessed according to normal partition standards, therefore this system would comply with the requirements of Approved Document B Vol 1 for natural smoke ventilation. For some projects, additional requirements might be made by the projects designers or consultants to achieve the fire strategy and this should be checked.

Care should be taken to fully seal the system in accordance with Siniat typical construction details (link to manual), post-construction leakage testing may be advisable if installation quality is uncertain.

Please note that gypsum products calcine when exposed to temperatures in excess of 50°C for extended periods of time and so should not be exposed to hot smoke on a repeated or continual basis.

Mechanical smoke ventilation in dwellings – ADB Vol1:

Limited guidance on mechanical smoke ventilation (including using pressure differential) is provided in clauses 3.54 and 16.11-16.12, this requires design to the EN 12101 series, fire resistance classification to EN 13501-4 and therefore testing to EN 1366-8/9. The Siniat A1 Shaftwall system has not been tested or classified to these standards and would not be considered suitable for  mechanical smoke control applications. Ductwork that has been proven to these standards should be used. Additional guidance can be found from the Smoke Control Association.