Xtratherm Flat Roof Board FR-MG
Xtratherm FR-MG mineral coated glass faced boards are suitable for use below single ply fully adhered roof membranes, mechanically fixed single ply waterproofing systems and partially bonded built-up felt systems.
  • High Thermal Performance
  • Suitable for fully bonding with approved adhesive systems
  • Compatible with adhesively bonded single ply roofing
    membranes laid on mechanically fixed boards
  • Mineral coated glass tissue facings
Note 1 ALU Note 2 ALU Note 3 ALU
TYPICAL PHYSICAL CHARACTERISTICS
PROPERTYUNITS
Density30 kg/m³
Compressive Strength>150 kPa @10%
Water Vapour Resistivity>100MNs/gm
Thermal Conductivity0.025 - 0.027 W/mK
Service Temperature-20°C +100°C

SPANNING
Xtratherm FR-MG insulation boards laid over metal decks should be in accordance with BS 4841:Part 3
mmTROUGH OPENING (mm)
2575
30>75100
35>100125
40>125150
45>150175
50>175200

TYPICAL 'U' VALUES
FR-MG Over Concrete Deck
THICKNESS (mm)U-Value (W/m²K)
500.54
600.45
700.39
800.33
900.29
1000.26
1200.21
1400.18
U-Values given are for insulation materials only. For comprehensive calculations on all deck types contact Xtratherm Technical Support.


TOLERANCE
DIMENSIONSSIZE (mm)TOLERANCE
Length1200+/- 5mm
Width600+/- 3mm
Thickness<60+/- 2mm
 ≥60+/- 3mm
DiagonalsDo not differ more than0.3%



XTRATHERM FR-MG SHEET SIZE
DIMENSIONSSIZE (mm)
Length1200
Width1200600
Thickness25 | 50 | 60 | 70 | 80 | 100 | 110 | 120
Other sizes are available subject to quantity and lead time.


Vapour control layer (when required): Mechanically fixed boards. A 1000 gauge polythene layer lapped and sealed with double sided tape should be used below the insulation.

Bonded boards. The insulation boards are embedded in a layer of bitumen on a 3b type felt to BS 747:2000 (Reinforced bitumen sheets for roofing. Specification) that has been adhered to the deck. (Xtratherm recommend that all should have mechanical fixings included)

Roof Design: 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 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.

See the Specification Clause

Xtratherm FR-MG mineral coated glass faced boards are suitable for use below most single ply fully adhered mechanically fixed roof membrane systems and most partially bonded built-up felt systems.
Xtratherm FR-MG 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.
Xtratherm FR-MG 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-MG insulation boards are generally secured by approved mechanical fixings. The requirement for a separate water vapour control layer should be assessed in accordance with BS6229 1982.


INSTALLATION GUIDELINES

Flat Roof Insulation

Vapour Control Layer
Please contact Xtratherm Technical Support for advice on membrane and adhesive system compatibility. Technical guidance from the appropriate waterproofing manufacturer should be sought.

The water vapour control layer should be laid with all joints lapped and sealed (150mm) and 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 - Concrete Deck
Decks should be dry and clean of debris, and laid to correct fall.

The boards should be secured using approved mechanical fixings and washers, with boards laid with a break–bonded pattern, all joints must be supported by the decking. Joints should be closely butted.

Alternatively the boards can be adhered to the decking with an approved bituminous adhesive system.

Laying - Metal Deck
Xtratherm FR-MG boards are laid as per instructions for concrete deck. Care should be taken to ensure that the metal 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.
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