XTRATHERM FR-ALU SHEET SIZE

DIMENSIONS	SIZE (mm)
Length	2400
Width	1200
Thickness	25 | 50 | 60 | 70 | 75 | 80 | 100 | 110 | 120

Other sizes are available subject to quantity and lead time.


Roof Finishes: Consideration should be given to the recommendations of BS4841: Part 3 1987 and those of the Single Ply Roofing Association.

Falls: The fall on a flat roof should be constant and steep enough to ensure that rainfall does not pond. Care must be taken to provide adequate falls ie not less than 1-80 to rain water outlets.

Fire: The fire rating when tested to BS 476 Part 3: 1968 "External Fire Exposure Roof Test" will be dependent upon waterproofing system specified. Xtratherm FR-ALU will typically achieve FAB rating.

See the Specification Clause

Xtratherm FR-ALU is faced with a gas-tight foil face.

Xtratherm FR-ALU foil faced roof boards are suitable for use below single ply mechanically fixed roof membranes.

Note: FR-ALU is not suitable for applications with built-up bitumen based roofing or mastic asphalt systems.

Xtratherm FR-ALU foil faced insulation boards are suitable for use on roof decks that are subject to maintenance traffic. Walk ways should be provided on roofs requiring regular pedestrian access. When the roof is complete, protective boarding should be laid if additional site work is to be carried out. The completed roof should not be used for storage of heavy materials or air conditioning plant

Xtratherm FR-ALU insulation boards should be laid over the vapour control layer in a break bonded pattern. The long edges of the boards should be laid at right angles to the corrugations and all board joints must be fully supported by the deck. The FR-ALU insulation boards are secured by approved mechanical fixings.

The requirement for a separate water vapour control layer should be assessed in accordance with BS6229 1982. When a vapour control layer is necessary, 1000 gauge polythene should be used. Any fixings that penetrate it must be of the self sealing type that fuse to the vapour control layer during applications.

Flat Roof Insulation

Vapour Control Layer
The water vapour control layer should be laid with 150mm laps, which are turned up at any vertical upstand. When the insulation boards have been positioned the laps are turned over and sealed, prior to the roof finish being completed.

Laying - Metal/Timber Deck
Xtratherm FR-ALU foil faced boards should be laid over the vapour control layer in a break bonded pattern. The long edges of the boards should be laid at right angles to the corrugations and all board joints must be fully supported by the deck. The FR-ALU insulation boards are generally secured by approved mechanical fixings.

Laying - Concrete Deck
Xtratherm FR-ALU boards are laid over the vapour control layer in a break bonded pattern and secured with approved mechanical fixings, or secured under ballasted system. Care should be taken to ensure that the concrete deck is graded to the correct falls, is dry, clean and free from any projections or gaps.

Fixing
The specification for fixing of Xtratherm roof boards will vary with the location, roof height/width and topographical data, architectural specification should be consulted.

Generally with 1200 x 600 boards, a minimum of 4 fixings are adequate, located between 50mm and 150mm from all edges, additional fixings may be placed along the centre line. 11 fixings per 2.4 x 1.2m sheet is recommended. Counter sunk washers, 50mm in diameter should be used with each fixing. However, BS6399 Part 2 1995 should always be consulted. During the construction process, the construction should be protected from rain penetration during breaks in the process.