Manthorpe Non-Combustible Extension Sleeve G1361

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The G1361 Non-Combustible Extension Sleeve is designed to provide incremental depth and span extensions to the range of Non-combustible Underfloor Ventilation products to provide a clear, unobstructed airflow passage to a void beneath an insulated suspended floor. The vent is constructed from Stainless Steel in order to be non-combustible and offer no contribution to fire.

The evolving requirements of Part L of the Building Regulations in pursuit of energy efficiency have led to an increase in the depth of thermal insulation in suspended floors along with an increase in cavity widths to accommodate greater amounts of cavity wall insulation. This has meant that clear access to an underfloor void may require a significant vertical drop along with a large horizontal span to bridge over from the inlet point in the outer leaf.

The range of Non-Combustible Underfloor Vents (G1365 & G1368) already cover a wide range of course depths and wall thickness, however for those detail which require it the G1361 can extend them even further. The Extension Sleeve will add an extra 150mm for each unit used, that is 2 further courses when used vertically and 150mm when used horizontally on either the upper or lower outlet.
For plinth brick and wider bed depth details the G1361 can be installed into the upper outlet of a Non-Combustible Underfloor Vent, with the Grille Slip affixed to the opposing end to allow the vent to extend across an increased bed depth of the outlet leaf beyond that of a single brick (102mm).

Due to the design, manufacture and telescopic adjustability of the products, the ducting paths are not airtight along their length there will be a limited degree of leakage both into and from the cavity void to the ducting channel.