SecilTek Isovit Render System
This is a breathable render system, formulated with natural hydraulic lime, mixed with carefully selected aggregates, used as a finish in the renovation and retrofit of building where natural fibre insulation boards are being used.
The Isovit render system is specifically designed for finishing natural fibre insulation boards, such as the Schneider Woodfibre or the Amorim Cork boards, it can also be used over the CEWood Woodwool boards.
This is our preferred solution for finishing any of our boards externally, this system can also be used internally if required but we prefer tu use the TopLime Hemp plaster for a softer and more breathable finish.
The system comprises of a base coat of the Isovit Lime (also used to adhere the insulation boards to solid masonry), reinforced with a render mesh. This provides a robust and flat surface for the application of the Reabilita Cal AC Top coat.
The Reabilita Cal AC top coat can be finished with a float, a steel trowel or a sponge depending on the desired surface finish. With a steel trowel it is possible to achieve a tight finish suitable for internal or external use, however if a polished finish is required an additional coat of Reabilita Cal AC Fine can be applied.
Base Coat
- Isovit Lime is applied with a 8-10mm notched trowel directly to the surface of the board, a render mesh is gently pressed into the surface preserving the ridges formed by the notched trowel. This application is important to ensure the proper spacing between the mesh and the face of the boards.
- Under no circumstances should the mesh be fixed to the board before plastering and the boards should NOT be damped down prior to application.
- The render mesh should be overlapped by 100mm at each edge.
- After the first layer of Isovit begins to harden (6-24 hours), a second coat of the Isovit Lime is applied to infill the ridged formed by the notched trowel and to cover the render mesh. Overall the thickness of Isovit Lime should be approximately 6mm thick with the render mesh embedded in the center of the plaster. The surface must be flat and even with a consistent surface texture across the whole wall. This levelling coat must be allowed to cure for 14 days prior to applying the top coat and must not be exposed to weather.
Finish Coat
- The Reabilita Cal AC is applied in 2 passes for a total of 3mm, the second pass being applied after the first has started to harden (several hours) and then finished within the same day. The Reabilita Cal AC can be finished with a float, a steel trowel or a sponge depending on the desired surface finish.
- It is recommended to work in sections with natural breaks (ie an internal or external corner) in order to minimise the presence of working joints.
- After a drying time of at least 14 days the render can be finished with a suitable breathable paint such as the Beecks Renosil.
- External corners should be reinforced with an appropriate plastic render bead to reinforce the render.
- For external applications the bottom edge of the insualtion boards must be protected with a base rail which allows for a drip edge detail to support the bottom edge of the render, this also applies to the heads of window and door reveals.
Isovit Lime - 1.6m2 per 25kg bag @ 10mm thick
Reabilita Cal AC - 7m2 per 25kg bag @ 3mm thick
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Excellent thermal and acoustic performance
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Applicable for retrofitting or new construction
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Fine textured finish
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High water vapour permeability
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100% Lime based render system
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High environmental performance
Isovit Lime - 20kg Bags
Cal AC - 25kg bags

