SOFFIT PHENOLIC CORE BOARDS

Soffit application phenolic board is an effective thermal and fire performance solution in structural ceiling applications in commercial and residential buildings. Frequently used in commercial applications, such as car parks, it is perfect for both new build and refurbishment projects. Boards come with a surface that will accept a decorative finish and are tailor-made solution for people who want excellent thermal protection in their structural ceilings. The term ‘soffit’ usually refers to the underside of the overhang, which is visible from outside. The boards achieve a thermal conductivity (λ-value) of 0.022 W/mK. The term soffit rigid insulation typically speaks of the pre-formed sheets of insulation, with compressive strength of 120kPa, which can be bought in 2400mm x 1200mm (8’ x 4’) size. This makes them quick and easy to install, which is important given that they must be fixed in place overhead. Soffit phenolic panels are up to 50% more effective than other common insulation materials (such as PIR), however, boards will likely be the most expensive of all the soffit insulation options. Being low thermal conductivity insulation enables high levels of thermal performance to be achieved utilising thinner soffit sections of insulation. Moreover, phenolic closed cell content makes it highly resistant to water penetration and is supplied as a performance, rather than decorative product. As they’re closed cells they shouldn’t absorb moisture or water vapour, unlike open cell products. Available in a range of thickness such as 50mm, 60mm, 75mm, 80mm and 100mm. They meet certification for ISO 50001: 2011 (Energy Management Systems), BS/I.S. OHSAS 18001: 2007 (Occupational Health & Safety Management Systems), ISO 14001: 2015 (Environmental Management Systems), and ISO 9001: 2015 (Quality Management Systems). Soffit materials are stable, rot proof and will remain effective for the life span of the building, dependent on specification and installation. Further information may be found in our datasheet section.

SOFFIT PHENOLIC BOARDS MANUFACTURERS

Soffit phenolic boards are often associated with Kingspan® or Xtratherm® brands. The  Kingspan® K110 Soffit Board has been tested within the FM 4880 approval standard, which assesses the fire performance of building panels. K110 reaches Class 1, which means that it has very limited fire spread and fuel contribution in the event of a fire. On the other hand Xtratherm® SR/ST Safe-R is a BBA certified board with a Euroclass B-s1, d0 fire classification.

PRODUCTS

Kingspan Kooltherm K110 Plus | Xtratherm Safe-R SR/ST soffit insulation board 

SOFFIT PHENOLIC BOARD INSTALLATION

Soffit boards can be fixed directly to the concrete slab, onto battens or used with proprietary fixing systems, to provide an even surface. The lightweight rigid product is convenient to handle and allows for fast and easy fixing. It is finished with a foil facer which can be taped using a proprietary foil tape. 

DIRECTLY TO CONCRETE

• Where applicable, ensure cavity wall insulation has continued past the soffit insulation to reduce thermal bridging.
• Install board onto the soffit ensuring all joints are supported. Ensure joints are tightly butted. Any gaps or service penetrations should be addressed with propriety fillers and components in accordance with fire engineers specifications.
• Fix panel to soffit with approved fixings, ensuring the fixings penetrate the substrate by a minimum of 40mm. Generally 12 fixings (min shank diameter of 5.2mm) per board are required. Fixings should have a head diameter of at least 35mm. Distribute fixings evenly across the board, at max 600mm across and 800mm along, at a minimum of 50mm from the board edge and a maximum of 150mm. Refer to fixing patterns below for indicative purposes.
• Boards joints can be covered with a suitable cover strip.
• Fixings at board edges must be located > 50 mm and < 150 mm from edges and corners of the board and not overlap board joints.
• Depending upon the fixing type, insulation boards can also be fitted by a shot fired fixing method, which can result in significantly faster installation times. 
• The joints of boards should always be taped using a suitable 75mm min. wide self-adhesive aluminium foil tape.

Kingspan Kooltherm K110 Installation Pattern

FIXING TO TIMBER BATTENS

• Treated timber battens may be used to provide an even surface when direct fixing to the soffit is not possible. 
• The battens, measuring minimum 50mm x 40mm, should be mechanically fastened at minimum 600mm centres.
• Fix board to the timber battens with approved fixings, ensuring the fixings penetrate the substrate by a minimum of 40mm. Ensure joints are tightly butted and fill any gaps with expanding foam. Generally 12 fixings (min shank diameter of 5.2mm) per board are required. Fixings should have a head diameter of at least 35mm. Distribute fixings evenly across the board, at max 600mm across and 800mm along, at a minimum of 50mm from the board edge and a maximum of 150mm.
• When using proprietary metal grid systems refer to the manufacturer for fixing instructions. Board joints can be covered with a suitable cover strip.

Where the insulation boards may be subject to external wind pressure, wind loadings should be assessed in accordance with BS / I.S. EN 1991–1–4: 2005 + A1: 2010 (National Annex to Eurocode 1 Actions on Structures. General Actions. Wind Actions) taking into account:

• length / width / height of the building,
• orientation of the building,
• wind speed.

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Picture credit:https://www.kingspan.com/

Video credit:https://www.youtube.com/watch?v=AFDc0RSoU58