As part of its continual evolution, Metsä Wood’s (formerly Finnforest) Finnframe flooring system now boasts a number of new developments that further improve the acoustic and energy performance of the system. Furthermore, Metsä Wood has also recently introduced a range of cost effective Kerto Q Rim Board detailing for use in timber frame structures. These developments help housebuilders, developers and timber frame manufacturers meet ever-changing regulations, while providing them with even more choice, flexibility and commercially pragmatic solutions.
Finnframe is a fully engineered flooring system, which combines a quality engineered timber system with bespoke design technology, underpinned by Metsä Wood’s technical service and support. The Finnframe product range is made up of Finnjoist, Kerto S, Kerto Q and the Finnframe software package.
Acoustically, Finnframe enables housebuilders and developers to exceed 43dB and comply with the acoustic requirements of the 2010 Scottish Building Regulations for intermediate floors as the system has been successfully tested at 44dB. In order to exceed 43dB, which is requested in section 5.2.1 of the Regulations, Finnframe has met a number of key elements, which include a 22mm P5 chipboard, 220mm deep Finnframe floor, 100mm insulation between joists and 15mm wallboard.
Further research and development by Metsä Wood in thermal modelling has also provided more precise measurability when it comes to the psi values of the building fabric. In terms of the energy efficiency of a building, heat can be lost in three ways – through holes in the fabric (air leakage), through the actual fabric of the building (u-value) and through cold bridges between building elements such as roof/wall (y-value). With this, every new build needs to have a SAP assessment of its energy efficiency. The SAP calculation requires three values – air leakage, u-value and the psi value. Psi values are calculated by thermal modelling and are needed to calculate the y-value, which is the percentage of heat loss compared to the total area of the envelope.
A housebuilder or developer has a number of choices in determining the y-value; they can use the default figures provided, use accredited details or use a system, such as Finnframe, that has a set of thermally modelled details. With the specification of Finnframe, housebuilders and developers can save on costs and improve the SAP rating of their units. In addition, it is also possible to offset the Finnframe psi values in the SAP calculation against other building elements. The result is that, with the Finnframe system, it is now possible to gain over 91% greater energy efficiency.
Another key development for Finnframe is the Kerto Q Rim Board for the timber frame sector in the very topical area of fire resistance. The new addition is created from Kerto Q, a fully engineered laminated veneer lumber (LVL), which is cross-bonded. Kerto Q rim board transfers the load through the floor zone from wall panels above and is an integral structural component available in a variety of depths and thicknesses. The result is a product that provides exceptional dimensional stability in addition to high compressional strength whilst providing a consistent surface for nailing and is fully certified with chain of custody and CE accreditation – features, which are ideal for Rim Board.
Using standard details Kerto Q is ideal for use in standard domestic dwellings and structures up to four storeys high. It is created using 27mm, 30mm, or 33mm Kerto Q in conjunction with 39mm and 45mm Kerto S and is available in depths to match Finnjoists of 200mm, 220mm, 240mm and 300mm – and is also available in depths to compliment metal web joist systems.
The solution, from 27mm, boasts up to 90 minutes fire protection when used in buildings of up to four storeys with detailing that has been independently verified. Furthermore, the rim board is PEFC certified and carries full, independently audited chain of custody accreditation. In addition, the solution is CE marked.
“FinnFrame is a continually developing system, which Metsä Wood has invested in to deliver increased performance to customers. These new developments will allow housebuilders to offer even more, make use of a cost effective and versatile system while ensuring greater steps are taken towards zero carbon of the building fabric,” comments Kevin Riley, Vice President Construction Industry UK for Metsä Wood.
For more information on Metsä Wood visit www.metsawood.co.uk or call 01205 883835.