Case. Mäntynummentie. A ventilated rainscreen cladding system with a seamless render finish is rapidly becoming more widely used.

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1 Case 1 Mäntynummentie A ventilated rainscreen cladding system with a seamless render finish is rapidly becoming more widely used.

2 2 In Lohja, a block of flats constructed using elements in the 1970s, is visibly more stylish, energy-efficient and weather-resistant than it was at the time it was completed thanks to a façade renovation made by Consti Julkisivut Oy. Weber s SerpoVent cladding system is a handy way of implementing a modern ventilated façade that is safe, durable and good-looking as regards the technical qualities of the structure with regard to moisture, and one to which additional thermal insulation can easily be combined. The improved appearance of a property and the fact that it is more comfortable to live in also increase its value. Facts Product: Address: Designer: Cembrit Permabase Mäntynummentie 23, Lohja Arkkitehtuuristudio Saari, Arkkitehti Mika Saari Contractor: Consti Julkisivut Oy / Asuntokorjaus Completion year: 2015 The ventilated cladding system enables an architecturally high-quality and uniformly rendered façade that will be durable and reliable as a ventilated structure in the harsh climate of Finland also in the case that insulation thicknesses increase. In the last couple of years, the cladding system has rapidly become more widely used. It is clear that its share will continue to increase rapidly, says Project Manager Juha Ilvonen from Consti Julkisivut Oy. Consti Julkisivut Oy is the largest façade contractor in Finland, and Consti Group is the largest company specialised in renovation construction.

3 3 One key reason for the fact that the cladding system is becoming more widely used is the security due to the moisture technical functionality and safety provided by the ventilated structure in both new buildings and renovations for property owners, residents and contractors. The importance of a ventilated structure is increased further when additional insulation is installed in buildings in connection with façade repairs. Many benefits are combined in the ventilated cladding system. For this reason, Lohjan Vuokra-asunnot Oy also decided to use the ventilated cladding system in the façade renovation of a block of flats on Mäntynummentie in Lohja. The block contains 55 flats, and an additional insulation of 100 mm mineral wool will be installed in the walls in connection with the renovation. There are a few more work phases to be carried out when a ventilated cladding system is used compared to insulation cladding, which is placed directly onto thermal insulation without a ventilation gap. As a large façade contractor involved in many projects, we only have positive comments on the ventilated cladding system solution thanks to its improved durability, says Ilvonen. Good experiences of the Serpo Vent cladding system over a period of more than 20 years In Lohja, it was decided to use Weber s SerpoVent cladding system in the façade renovation. In Finland, good experiences of the system have been obtained over a period of more than 20 years. Cembrit s cement-based and strong PermaBase panel is used as the base for the rendering. When we select suppliers, we pay particular attention to the overall price. We only use major material suppliers who have proved to be reliable as, in terms of the contractor s responsibility and warranty, there is always a risk with minor operators that the company in five years will not exist, says Juha Ilvonen. Supervisor Joni Kiiskilä from Consti Julkisivut Oy says that the exteriors of concrete sandwich elements were first dismantled from the end walls that had no windows and the old 100 mm thermal insulation was removed. Then, a metal frame system was installed at the ends to which the new façade structures were attached together with 200 mm mineral wool. Windstopper panels were installed on the thermal insulation. A ventilation gap was left on top of the windstopper panels. Finally, Cembrit s PermaBase panels were attached to the support frame, and Weber s SerpoVent cladding system was implemented on top of them. The exterior of the sandwich elements was left as it was, and the metal support frame was attached to the exterior elements. After this, the work phases

4 4 and structure layers were the same as at the ends. In addition to the 100 mm insulation of the original elements, an additional insulation of 100 mm was installed on the walls with windows. The elastic seams of the façade elements were removed and the seams were filled with mineral wool. In that way, any moisture will be able to escape from the structure, Joni Kiiskilä says. It is cheaper to implement a structure that is not ventilated, but this kind of a ventilated cladding system is one of the best kinds of façade structures. The wall structure will remain dry thanks to the ventilated structure, says Kiiskilä. The façade repair was started in May and completed in August. All windows were also replaced with more energy-efficient ones and the balconies were repaired, says Kiiskilä. Weber s two-coat rendering is durable and maintenance-free Product Manager Antti Saajanlehto from Weber says that the ventilated cladding system is suitable for all frame types. In addition to the ventilated structure, Weber s two-coat rendering and silicone resin coatings on the walls will make them maintenance-free and very long-lasting against strain due to weather. Once the coating has been implemented using Weber s two-coat rendering included in the system and silicone resin-based Silco paint and Silco coating, the wall will be able to resist extreme stress due to moisture and the varying weather conditions in Finland, Saajanlehto says. In the case of the two-coat rendering developed by Weber and based on advanced material technological expertise, the base rendering is performed using weber.vetonit thin render reinforced with glass fibre net that forms a durable base for surface rendering. The silicone resin-based surface rendering implemented on top of it forms a watertight surface for the façade that is resistant to water and nevertheless breathes well. The European standard requires a durability of five cycles in a weather stress test for a wall structure

5 5 without damages to the structure and surface. Weber has performed a test including a hundred cycles, in which case the reliability of the structure is more than 20-fold compared to the standard, and therefore, we are very confident in it, Saajanlehto assures. In addition to excellent watertightness and durability, one benefit of the silicone resin coating developed by Weber is that it forms an opaque surface that is uniform in colour and will not be subjected to deposition. The surface also has high resistance against impact and mechanical strain. The selection of colours and surface options is almost unlimited, says Antti Saajanlehto. In his view, contractors have given good feedback on Weber s comprehensive equipment service and technical support, high quality and incomparable system warranty. Cembrit s PermaBase panels provide a durable base for rendering Sales Manager Jussi Pesonen from Cembrit estimates that the growing popularity of the cladding system that has been experienced in the last 3 4 years will continue, and the solution will become more widely used as is the case in Sweden. A ventilated structure is always a more secure solution for the moisture technical functionality and durability of a wall structure as a whole. weather-resistance of the panels has been tested, and they will not rot or expand due to moisture. In addition to a ventilated façade, the cladding system enables the fact that there is plenty of room for fitting thermal insulation inside walls without the need to thicken them by, for example, using tile cladding as the base. This way, we can ensure that the complete thickness of the façade will not increase excessively so that the architecture and light inside flats will not suffer, which could be the case if the windows were left too deep in the façade of the building. When the façade renovation will be completed, residents will be able to enjoy the comfort of living in a block of flats that has reached a new level aesthetically and in terms of its heat conditions. Improved energy-efficiency will significantly reduce the heating costs and carbon dioxide emissions of a property. A renovation will also always offer a good opportunity to improve the energy classification of a property and increase its value. When the ventilated cladding system is combined with additional thermal insulation and new windows, it will also clearly improve the sound insulation of a property, says Jussi Pesonen. The ventilated rainscreen cladding system is a safe solution that will easily lengthen the service life of a façade by 50 years. Thanks to its excellent longterm durability, it is also a cost-efficient solution, Pesonen says. Cembrit s cement-based PermaBase cladding panels that have been reinforced on both sides with a fibreglass mesh form a very strong and durable base for rendering. Panels can easily be worked at a worksite. The low water absorption level of the panel lengthens the time the rendering can be worked. Thanks to the patented structure, screws can be attached very close to the edge of the panels. The

6 Cembrit P.O. Box 46 Mineraalintie Lohja Tel info@cembrit.fi Cembrit is part of one of Europe s leading manufacturers of building materials: Cembrit Holding. The Group s main products are fibre-cement based roofing materials and cladding. To bring out the best in these products a range of specially adapted fittings and supplementary equipment has been developed. This makes it possible to find a architectonic solution to any roofing or cladding assignment whether the building in question is for business, private, farming, industrial or any other purpose. The products are manufactured at technically advanced and professional factories and they are sold through a professional network of subsidiaries and distributors. Our expertise and personal commitment are integral parts of all Cembrit solutions, whether they are concerned with products, service backup or partnership.