Application and system
HANDLING AND STORAGE
Always store indoors, the material must not be exposed to water or high humidity levels. During transportation the boards should be placed in upright position (edgeways) and should be handled carefully to avoid damaging the edges. To cut, start by cutting the surface reinforcement mesh on one side with a cutter, fold the board to break it and then cut the reinforcement mesh on the other side.
ENVIRONMENTAL CONDITIONS
Before installation the boards must be acclimatized to the temperature and humidity level of the environment. The temperature should not be below 5°C. When applying the filler and finishing, the temperature must be between 5° and 40°C with relative humidity below 80% during application and for 48 hours following completion.
Before assembly ensure that the boards are perfectly dry; do not install the boards if damp.
SUPPORT FRAME
All the wall and double wall profiles must be constructed as set forth by UNI EN 14195 standard in cold laminated steel hot coated with aluminium and zinc or zinc and magnesium alloy as set forth by UNI EN 10346 standard. The thickness of the profiles should be between 0.6 and 1.00 mm and must be positioned at a centre distance varying from 400 to 600 mm; the structure must be dimensioned according to the static requirements of the project and wind pressure. All fixing elements, accessories, nuts and bolts should be resistant to aggressive environments, namely they should be made of stainless steel or have a coating ensuring salt spray test resistance of 1,000 hours.
WATER-PROOF TRANSPIRING BARRIER
MGO Boards are resistant to water but are not waterproof; if condensate forms in the air space therefore, the boards may absorb humidity from the inner side (which is not treated with a finishing coat). To prevent this, an anti-condensate barrier consisting of a waterproofing vapour-transpiring membrane should be placed between the structure and MGO Boards. If the board is installed vertically, the membrane should be fixed temporarily to the structure from the bottom to top, positioning the sheets horizontally and overlapping the edges of the layers by at least 10 cm.
If the boards are laid horizontally, the edges of the membrane should in any case be overlapped by at least 10 cm.
INSTALLING THE BOARDS
Install the boards horizontally (transverse to the profiles) in staggered joints, with the rough surface facing outwards, screwing them to the metal frame with the special MGO Screws which are highly resistant to corrosion (salt spray test resistance of 1,000 hours) at a centre distance of no more than 200 mm. Leave a space of 3-4 mm between the edges of the boards, which will then be filled by the first coating of plaster.
FILLING
The joints between the boards must be filled with outdoor MGO Filler Dry which should also be used to finish the surface. Apply only one coating of filler interposing the alkaliresistant reinforcement tape; once the filler has cured, apply the finishing coat.
FINISHING COAT
Smooth off the surface with MGO Filler Dry filling the joints for a thickness of about 3 mm; bury the alkali-resistant fibreglass mesh completely in the finishing coat overlapping the edges by at least 10 cm. Allow to cure for 24 hours then apply the second finishing coat. Before applying any other finishing, allow the filler to dry and harden for at least 48 hours.
INSTALLATION OF THE FINISHING PROFILES
Fix the PVC finishing profiles (edge beams, drips, expansion joint covers, frames etc.) burying the mesh section into the finishing bed and overlapping it on the edges of the alkali-resistant fibreglass mesh. In particular cases, the profiles may be fixed to the metal sub-structure with the same screws used for the boards, or to the boards with metal clips.
INSTALLATION OF THE EXPANSION JOINTS
The expansion joints should be installed at intervals of 6 m; the joints should also be used in the following cases:
– In proximity of the expansion joints of a building.
– In proximity of floor divisions of a building.
– When materials of the structure or facing of the building are changed.
In proximity of the expansion joints it is in any case necessary to interrupt the frame of the metal support.
WATERPROOFING OF THE PACKET
Considering that the boards are not waterproof and have a low resistance coefficient to water vapour, the outer surface must be treated with MGO Filler Dry which amongst other things, waterproofs the boards while allowing the dispersion of condensate that forms in the air gap when it becomes water vapour. To ensure complete waterproofing of the boards the thickness of the finishing layer must be at least 3 mm. An anticondensate barrier, consisting of a waterproofing vapour-transpiring membrane, must always be positioned on the back of the board. The packet as a whole is certified by a waterproofing test in accordance with UNI EN 12467-2007 standard (Istituto Giordano Test Report No. 282489 dated 28/03/2011). Any absorption of water before application of the finishing coat will not damage the boards; before applying the finishing coat however, ensure that the boards are perfectly dry and that the temperature is between +5°C and +40°C with relative humidity under 80%.
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