- stronger adhesion
- easy application
- frost-resistant after curing
- very good physical and mechanical properties
KU 21 Adhesive for fibreglass mesh is intended for making a reinforced coating with fibreglass mesh in thermal insulation systems performed via BSO method (light-wet). It is also intended for installing polystyrene panels to all construction substrates: concrete, silicate, ceramic, cement, cement and lime renders, etc. It can be used for both exterior and interior purposes in new buildings and ones being under construction.
It can also be used to fill in any irregularities and cracks on stabilized substrates. It comprises of FOVEO TECH S thermal insulation system.
|Appropriate water amount:||approx. 5.0 - 6.0 litres/25kg|
|Application temperature:||between +5ºC and +30ºC|
|Open working time (from application to panel installation):||to 20 minutes|
|Adhesive workability (after mixing with water):||approx. 1 hour|
|Curing time:||between 6 and 24 hours|
|Average consumption per 1 m2 for edge and pointwise application:||between 3.5 and 4.5 kg|
|Average consumption per 1 m2 for the whole surface application:||between 5 and 6 kg|
|Average consumption per 1 m2 for reinforcing layer:||between 4.5 and 5.5 kg|
|Adhesion to concrete:||≥ 0,3 MPa|
|Adhesion to polystyrene:||≥ 0,1 MPa|
|Expiry date:||12 months|
Put 5.75–6.25 litres of cool water into a clean container and put the whole content of the adhesive i.e. 25kg (0.23- 0.25 litres of water per 1 kg of powder) mixing it continuously. Mix it with a slow-speed drill till obtaining a uniform consistency. Mix it again after 5 minutes. Then mix it again and adjust the consistency by adding a small amount of water. Do not add any other substances except water. Workability time after mixing with water is up to 1 hour. In case of curing, it’s necessary to remix it without adding any water or fresh adhesive. Adding too much water impairs the adhesion features: to the substrate, peeling resistance, curing time. Polystyrene panels installation: The substrate intended for the installation of polystyrene panels must be even, dry, solid, as well as dust, contamination, bacteria (fungi, mould, mosses) and other chemicals free, etc. All contamination must be washed under high water pressure. Old render and paint coatings of poor adhesion must be removed. Fill in any cracks with adhesive KS 20 or KU 21 (max. up to 6.0 mm on one coating) or standard render mortar. It’s recommended to apply GA 10 Acrylic Primer, 24 hours before the installation of polystyrene on substrates with poor load-bearing capacity, very absorptive and chalky (i.e. leaving dust traces after palm rubbing) in order to strengthen them and reduce the absorption. Polystyrene can be installed on fresh cement, cement-lime plasters after min. 14 days, while on concrete after min. 30 days. All substrates must be stabilized regarding the moisture level and the hardening process must be completed. In the event of applying polystyrene panels on substrates with poor load-bearing capacity, it is necessary to carry out adhesion test. Install a few sample polystyrene blocks of 10x10 cm dimensions and remove them manually after 4-7 days. The substrate is appropriate if the polystyrene is torn inside. If, however, the adhesive coating is removed with the polystyrene block and the substrate coating, it’s necessary to remove the poor coating and apply GA 10 Acrylic Primer - 24 hours before the polystyrene installation. Reinforced layer: The entire surface of the installed polystyrene panel must be smoothed with the sandpaper, if necessary use fixing anchors for support. If the polystyrene panels are not covered with the reinforcing layer within 14 days, it’s necessary to estimate their condition - yellow and dusty panels must be smoothed with the sandpaper. In order to strengthen the corners and edges use corners with mesh.
Polystyrene for thermal insulation via BSO method should comply with PN-EN13163 standard. When applying on walls, put the adhesive alongside the edges of polystyrene panel - min. 3 cm wide and 1-2 cm thick, while pointwise while pointwise - 8-12 cm diameter adhesion layers - remember to place the same adhesive amount on the panel symmetrically. The total amount of applied adhesive should cover at least 40% of the panel’s surface, and 60 % after pressing it to the surface. In case of smooth substrates and ceilings, as well as plinths apply the adhesive on the whole panel surface with a comb trowel (at least 10x10 mm).
After the application, the panel must be immediately applied to the wall in the appropriate area and pressed so as to obtain a flat surface with the neighbouring panels. The panels must be installed alternately and tightly jointed to the previously installed ones. The panels must not be pressed twice or repositioned. Gaps bigger than 2 mm must be filled with polystyrene stripes. Minimum 24 hours after installation, the surface must be smoothed with sandpaper and protected by installing additional fixing anchors in accordance with the technical design or ITB Manual no. 447/2009. It’s recommended to use 4 anchors every 1/m², whereas near the edges and plinths 6-8 anchors every 1/m². The depth of anchors should be at least 6 cm in case of solid substrates, and 8 cm on light substrates.In case of masonry units the anchor must go at least through two walls of the unit.
The reinforcing layer can be made min. 3 days and not later than 3 months after the installation of polystyrene. If the polystyrene is not covered with the reinforcing layer within 14 days, it’s necessary to estimate its condition - yellow and dusty sheets must be smoothed with sandpaper. Before the adhesive application on the whole surface it’s necessary to install additional diagonal mesh pieces - 20x30cm - in the corners. Mesh stripes must be also installed in interior corners of window frames. Apply the adhesive with a comb trowel on previously prepared and dust-free mineral wool panels and attach the fibreglass mesh to it.
Attach the mesh making vertical stripes leaving 10 cm gaps, and then smooth it to cover it completely. The mesh must not adhere directly to the polystyrene and cannot be visible. If necessary, apply another coat of the adhesive and smooth the surface and any imperfections after drying. The reinforcing layer must be at least 3 mm thick. On the ground area you must install two layers of the reinforced mesh or fibreglass armour mesh. The render can be applied at least 3 days, but no later than 3 months, after the reinforcing layer was made. Before the render application it’s recommended to paint the surface with primer PA 10 , PT 20 or PN 30 (depending on the type of applied render).
Apply when the temperature is between +5ºC and +25ºC. Do not apply on heated substrate. During the render application and drying time avoid direct sun exposure, strong wind and rain. The temperature during application and over the next 24 hours cannot be lower than +5ºC. Hardened and mixed compound must not be mixed with water or fresh material. Do not put the adhesive one the edges of insulation panels. Works must be carried out in accordance with principle construction rules, as well as HSE standards and regulations. The manufacturer shall not be liable for any damages resulting from inappropriate use or mispurpose of the product.
Keep in dry and ventilated area in undamaged containers. Storage temperature should be between +5ºC and +25ºC. Protect from rain, frost and sunlight. Expiry date on the container.
Slow-speed drill, a trowel, steel comb trowels, container for the adhesive. The areas where the product was used or elements covered with the product must be ventilated until the odour vanishes completely. Only then can they be used.