The MBC Passive Roof system delivers a U-Value of 0.10W/m2K. The Passive Roof & Wall Junction detail shows how the 400mm Cellulose Insulation in the roof is precision fitted to overlap with the 300mm Cellulose Insulation of the Passive Twin Wall System at the eaves juncture. This overlapping arrangement of both the roof and wall insulation, safeguards that the structure is completely wrapped, and free from any thermal breaching.
The MBC Passive Roof System is suitable for all roof designs (flat, pitch, barrel vault, etc), ensuring your building design remains uncompromised. A typical pitched roof sees engineered timber trusses set @ 400mm centres with 25mm x 125mm diagonal bracing and longitudinal binders providing truss stability in accordance with BS 5268 Structural Use of Timber. The truss system utilises the tooth plate systems in which gangnail plates are hydraulically pressed into machine stress graded European whitewood, ensuring structural integrity.
Breathable roofing membrane is secured to the external face of the truss and fixed with 50mm x 38mm roofing battens. An 89mm x 38mm timber is fixed to the 225mm roof truss with a 86mm gap between, forming a 400mm roof void. 400mm Warmcell Blown Cellulose Insulation is pressure pumped between trusses and right out to the eaves edge, forming a deep insulating blanket, overlapping with the 300mm wall insulation. The airtight membrane system encases the insulation in the void space between each truss, and forms an impenetrable draught free seal. 38mm battens form a service cavity and provides a fixing for the internal ceiling plasterboard.