BS EN 771 is a European standard that discusses the specification for masonry units. The main objective of the BS EN 771 series it to provide best industry guidance to determine the quality and performance of construction products and materials such that they contribute to the structural integrity of your civil engineering works.
BS EN 771-4 is the fourth part of the series that specifies the characteristics and performance requirements of autoclaved aerated concrete (AAC) masonry units for which the main intended uses are different types of load-bearing and non-load-bearing applications in all forms of walling including single leaf, cavity, partitions, retaining, basement and general use below ground level, including walling for fire protection, thermal insulation, sound insulation and the fabric of chimneys (excluding chimney flue units).
BS EN 771-4 includes AAC masonry units with incorporated insulation not exposed to fire, and masonry units of an overall rectangular parallelepiped shape, specially shaped and accessory units. AAC masonry units may consist of layers of different densities where not all of the layers are loadbearing.
Note 1: BS EN 771-4 does not cover the requirements for storey height panels, flue linings and masonry units with an incorporated thermal insulation material bonded to the faces of the unit susceptible to be exposed to fire.
Note 2: BS EN 771-4 does not specify standard sizes for autoclaved aerated concrete units nor standard work dimensions and angles of specially shaped and accessory units.
Note 3: BS EN 771-4 does not give permissible deviations for specially shaped and accessory units.
Note 4: BS EN 771-4 does not cover products intended for use as a damp-proof course or the lining of a chimney.
BS EN 771-4 on masonry units is relevant to:
Autoclaved aerated concrete is an eco-friendly and certified green building material that are lightweight, load-bearing, high-insulating and durable building blocks. It is widely used in construction for building walls, floors, and roofs.
BS EN 771-4 provides the requirements and properties of autoclaved aerated concrete masonry units giving the performance related to strength, density and dimensional accuracy.
BS EN 771-4 also covers guidance on Assessment and Verification of the Constancy of Performance (AVCP) that ensures your products conform with the requirements.
In this regard, BS EN 771-4 provides the best industry recommendations on product description, designation and classification of autoclaved aerated concrete masonry units along with the marking requirement.
As a result, BS EN 771-4 assists you with the production of autoclaved aerated concrete masonry units that can offer effective fire protection, thermal insulation, sound insulation, and sound absorption for your building structures.
EN 771-4:2011+A1:2015