In light of recent discussions and a pivotal meeting in January 2023 involving floor joist manufacturers and the NHBC Standards, Innovation and Research team, they have issued updated guidance concerning the construction and inspection of floors in new build homes. This comes as a response to multiple enquiries and the need to clarify their stance on the standards required for ensuring floor integrity and safety.
The existing guidance stipulates that the maximum allowable deflection in floors should not exceed 0.003 times the span for the combined bending and shear, factoring in both dead and imposed loads. This guidance sets forth a maximum deflection limit of 14mm when strutting is provided, and 12mm in instances where strutting is absent. Importantly, it has been clarified that the term ‘maximum deflection’ refers specifically to the instantaneous deflection experienced by the floor, rather than its final deflection after settling.
For buildings where the foundations were laid prior to 1 January 2023, the previous standards as established by NHBC will continue to apply. Consequently, there is no obligation for these properties to adhere to the newly updated guidance.
However, for both new and existing developments where the foundations were established post-1 January 2023, but the flooring was supplied, stored, or ordered before this date, there is a transitional period in place. Up until 30 June 2023, floors that were designed in accordance with the prior NHBC standards will still be deemed acceptable. Following this transitional period, starting from 1 July 2023, all newly installed floors must conform to the latest requirements set out in the new guidance.
This update aims to enhance the structural integrity and safety of floors in new build homes, addressing the concerns related to excessive floor deflection – commonly referred to as ‘bouncy floors’. To further assist homeowners, builders, and inspectors, we strongly encourage a thorough review of our comprehensive Knowledgebase article on this topic. It provides valuable insights into the causes, implications, and remedial strategies for bouncy floors in new build homes. Enhance your understanding and ensure your home meets the highest standards of safety and comfort by reading more about bouncy floors in new build homes here: Bouncy Floors in New Build Homes.
By staying informed and adhering to the latest standards, we can collectively ensure the durability, safety, and satisfaction that homeowners deserve from their new build properties.