As the construction industry and professionals involved in the building design process continue to face new challenges concerning the suitability of building materials, performance in relation to fire safety whilst still achieving excellence in terms of thermal insulation performance has become a critical issue.
To satisfy this demand, the A. Proctor Group Ltd, leading manufacturer of vapour permeable membranes and vapour control layers, provides a comprehensive systems approach to all projects whether new build or retro-fit.
The balance of Heat Air Moisture Management (HAMM)
The A. Proctor Group understands that a totally holistic approach is required to building design. In doing so we consider six core aspects in the process related to the balance of Heat Air Moisture Management (HAMM):
Understanding the importance of these key elements upon the building envelope is crucial to the successful construction and performance in use of the building, as well as the health of its occupants and the wider environment.
Changes in regulations
With questions continuing to be asked about the suitability of certain materials within the construction of tall buildings, the increased requirements for fire safety mean that the use of limited or combustible products within the façade has changed, and the correct selection and application of materials are at their most critical.
In regards to insulation, this change will impact on the depth of material in the façade due to the reduced thermal performance inherent with non-combustible products. This lends itself to looking at other performances such as the airtightness of the building, which is the specialist expertise offered by the A.Proctor Group who can advise on the appropriate insulation.
By moving the air barrier to the external side of the structural frame, external air barrier systems such as Wraptite® from A. Proctor Group allow for an almost penetration-free airtight layer, which can be installed faster and more robustly. This offers an effective but simple system comprising a self-adhesive vapour permeable air barrier membrane, plus vapour permeable sealing tape, Wraptite Corners and Wraptite Liquid Flashing, and provides effective secondary weather protection while preventing trapped moisture and air leakage.
Wraptite complies with Part B amendments for use on buildings of high rise and over 18m. Under Part B, membranes need to be Class B,s3,d0 or better, whilst Wraptite is classified as Class B,s1,d0 when used over a Class A1 or A2 substrate.
Breather membranes and fire performance
In selecting a membrane it is important that performance is not compromised and that compliance meets the requirements of both Approved Document B: Fire Safety and BS5250 the Code of Practice for Condensation Control. Specifiers should understand that some European membrane products, whilst quoting A2 ratings, do not breathe sufficiently to comply with BS5250, meaning the use of these membranes in the UK climate could make the building unhealthy and result in a much greater risk of condensation issues and mould growth.
The culmination of years of research into membranes by the A. Proctor Group has led to the development of a vapour permeable membrane with a fireproof surface, which has a unique intumescent composition that actively reacts to prevent fire taking hold and that also significantly reduces the formation of droplets and smoke.
Fireshield® vapour permeable membrane is designed specifically to improve the fire protection behind cladding and has been awarded a British Board of Agrément Certificate and also has certification from both LABC and LABSS confirming that the product meets Building Regulation approval. Fireshield complies with BS5250, BS4016 and NHBC requirements for vapour permeable walling underlays. Applications include both commercial and residential buildings including apartments and student accommodation, as well as rainscreen cladding and applications over 18m high.
The latest development is Spacetherm® A2 providing a vapour permeable insulation with an A2 fire rating. The insulation is classified as Class A2, s1 –d0 according to the Euroclass system, which classifies the reaction to fire performance of building products. Spacetherm A2 is a flexible, high-performance, silica aerogel-based insulation material of limited combustibility suitable for use in exterior and interior applications, and optimises both the thermal performance and fire properties of façade systems, enhancing the thermal performance of the ventilated façade and addressing thermal bridging in the façade.
For more information on Thermal Insulation please click here.