Saint-Gobain Off-Site Solutions (OSS)

Description of the Saint-Gobain Offsite Solutions Intrastack Lightweight Steel Building System

Manufactured in the United Kingdom, the factory assembled wall, floor and roof panel cassettes are transported to site and assembled in sequence on a prepared sub-structure. The foundations, sub-structure and ground floor construction is site specific and usually constructed by others. They are not included in this assessment. The system uses a range of light gauge galvanised steel (LGS) C and U sections to create low-rise and medium rise building frames, floors and secondary components for single occupancy houses up to 3 storeys high and apartments not exceeding a height of 12 storeys high. The system comprises the structural panels and external wall sheathing only.

Limits on scope

• Maximum height of 12 storeys subject to structural analysis.
• Bottom members minimum 150mm above external ground level and isolated from damp.
• Minimum 50mm drained and ventilated cavity behind conventional masonry cladding.
• Minimum 25mm drained cavity behind external cladding systems, or as required by the manufacturer.
• Rendered external thermal insulation systems or insulated brick slip systems must have a minimum 15mm drained cavity.
• Assessment assumes cladding systems by installed by others are designed and installed to prevent moisture reaching the LGSF, e.g., EPDM taping around windows.
• Where cladding loads are to be directly transmitted to the LGSF structure, Saint-Gobain Off-Site Solutions must ensure the structure is capable of carrying the anticipated loads for all cladding types and, in particular, where masonry may be supported from the structure.
• Saint-Gobain Off-Site Solutions must be contracted for the design, manufacture, supply and erection of the structures.

Description of the Saint-Gobain Off-Site Solutions i-Roof prefabricated timber room-in-roof building solution

Manufactured in the United Kingdom, the factory prefabricated roof cassettes, purlins, spandrel and gable panels are transported to site and assembled in sequence on a pre-constructed superstructure constructed by others. The superstructure may be of masonry or timberframe, and must be specifically designed by others to receive the i-Roof system. The system is not intended to be used on existing buildings. The whole assembly is structurally interconnected to provide composite action in accordance with the requirements of the UK structural codes and as specifically designed for each structure.

Limits on scope

• Maximum 3 storeys including i-Roof.
• For use on new construction only.
• Saint-Gobain Off-Site Solutions must be contracted for the design, manufacture, supply and erection of the structures.
• A chartered structural engineer suitably experienced in the design of this type of structure must be engaged for the structural analysis and design.

Description of the Saint-Gobain Off-Site Solutions Thermistud timberframe building system

Manufactured in the United Kingdom, Thermistud is a closed panel timber frame system constructed largely of composite timber I-joists filled with mineral wool insulation and including a vapour control layer on the warm side, and breather membrane on the outside. Wall panels are combined with factory assembled floor cassettes, comprising solid timber joists, I- joists or metal web joists, and roofing solutions, generally conventional trusses, attic truss, or flat roofs to create low-rise residential properties 2 storeys high + room-in-roof option, not exceeding 7.5m above external ground level.

Limits on scope

• Maximum 2 storeys + room-in-roof (may go higher depending on future fire testing)
• Bottom members minimum 150mm above external ground level and isolated from damp with a suitable DPC.
• Minimum 50mm drained and ventilated cavity behind conventional masonry cladding
• Minimum 25mm drained and ventilated cavity behind dry external cladding systems, or as required by the manufacturer.
• Rendered external thermal insulation systems or insulated brick slip systems must have a minimum 15mm drained and ventilated cavity.
• Saint-Gobain Offsite Solutions must be contracted for the design, manufacture, supply and erection of the structures.
• A chartered structural engineer suitably experienced in the design of this type of structure must be engaged for the structural analysis and design.

Description of the Saint-Gobain Off-Site Solutions Valutherm+ timberframe building system

Manufactured in the United Kingdom, the factory prefabricated elements are transported to site and assembled in sequence on a pre-constructed substructure constructed by others. The whole assembly is structurally interconnected to provide composite action in accordance with the requirements of the UK structural codes and as specifically designed for each structure. All projects are subject to individual structural verification. The system may be used for dwellings up to five storeys high, including room-in-roof. The structural wall and roof panels system can be used as the loadbearing inner leaf of external walls, double leaves for separating walls, internal loadbearing walls, infill panels, floor panels and pitched/flat roof panels.

Limits on scope

• Maximum 5 storeys including room-in-roof.
• Bottom members minimum 150mm above external ground level and isolated from damp.
• Minimum 50mm drained and ventilated cavity behind conventional masonry cladding.
• Where suspended timber ground floors are used, the ground below the floor must be sealed to limit moisture entering the void, e.g., membrane + 50mm site concrete.
• Where voids below suspended timber floors are below external ground level, consideration should be given to draining the void (standing water not permitted).
• Where suspended timber ground floors are used sub-floor ventilation must be provided – minimum 1500mm2/m wall length or 500mm2/m2 of floor area.
• Minimum 25mm drained and ventilated cavity behind dry external cladding systems, or as required by the manufacturer.
• Rendered external thermal insulation systems or insulated brick slip systems must have a minimum 15mm drained cavity.
• Saint-Gobain Off-Site Solutions must be contracted for the design, manufacture, supply and erection of the structures.
• A chartered structural engineer suitably experienced in the design of this type of structure must be engaged for the structural analysis and design.

Description of the Saint-Gobain Offsite Solutions InteWall Panelised Partition System

InteWall is an offsite-manufactured panelised non-loadbearing partition system intended for use in all types of commercial and residential buildings. The panels are manufactured at Saint-Gobain Offsite Solutions’ Pasquill Ltd. manufacturing facility in Chorley, Lancashire. The panels are constructed from bespoke light gauge steel sections, fitted with Saint-Gobain’s Isover brand insulation and sheathed in British Gypsum brand plasterboard.

Limits on scope

• Maximum 4m high.
• Bottom steel members must be fully protected from contact with direct or indirect moisture.
• Sant-Gobain Offsite Solutions must be contracted for the design, manufacture and supply erection of the panels.