For a modular or panel built home to be signed off by Building Control, and hence acceptable to a mortgage lender, the property must have a design life of at least two mortgage terms or 60 years. As with most aspects of modular construction, there is no standard external cladding detail or choice of exterior finish; manufacturers choose their own approach as to how the finished house should look and be constructed.
Variations can include different finishes, i.e. renders, acrylic brick slips, clay brick slips and stone slips, and different fixing methods, i.e. ventilated cavity and direct fix. These are then fastened to oriented strand board (OSB), magnesium oxide (MgO) board or cement particle board and onto either a timber frame, light gauge steel frame or structural insulated panel (SIP). This includes just a few of the variations of different systems available and used, which can be in any combination. Due to the number of variations, there is not a "one fix fits all" solution to prove a system will have the durability to achieve a 60 year design life both aesthetically and physically. It is crucial that systems remain water tight and maintain their thermal performance over the working life of the building.
Systems require testing to the correct standard and must be tested as the complete system, and not as individual components making up the system. The appropriate testing regime will enable the system to be classed as acceptable for a design life of +25 years, however an additional study is required to allow the 60 year durability label to be applied. A comprehensive desk study considers the full detailing and all of the components and fixings used in the construction of the system.
Lucideon are hosting a webinar on Thursday 14 March 2019 at 15:00 (UK time, 10:00 EDT) which will outline the different testing standards and techniques available to prove the performance of various systems and how these vary for different material combinations. A case study will be used to explain the process of the 60 year desk study exercise and examine the limitations of component testing as compared to system testing.
Lucideon Webinar: Testing the Durability of Offsite Residential Buildings - To find out more and/or to register, please click here.