K REND BASE COATS
Standard UF Base, UF Fibre Base, HP12, HP14, HPX Base Primary coat, where required, should be applied to substrates as preparation for subsequent coats of K Rend scraped texture finishes. Thickness should be as per product specification. It is important to take special care to straighten with a darby / straight edge to ensure that the next coat is applied to uniform level. Form a light key only. If you are applying K Rend Silicone TC as a finish coat, do not form a key and leave the base coat flat and smooth. Allow 24 hours curing time before further application, unless advised otherwise, for instance it is recommended to allow 14 days curing time before the application of K Rend Silicone TC top coats to guarantee adhesion. For info on unusual substrates, seek technical advice.
Base Coat Recommended Thicknesses
4-6mm: HP12, HPX
8-10mm: UF, UF Fibre Base
K REND SCRAPED TEXTURE
Silicone FT, Silicone Spray E Grade, K1 Spray, K1 Silicone
ONE COAT / FINISH COAT
One coat is applied directly onto block work (please seek advice from our Technical team) and must be finished to a minimum of 16mm thick to avoid ‘ghosting’. The material should be applied 18mm thick in 2 passes; the first pass 6-8mm and the second pass 12 - 14mm. (See also under Spray Application). After setting, 2mm is scraped off for a 16mm finish. If the material is being used in a two coat application the Finish Coat is applied over a K Rend Base Coat to line level, using a darby or straight edge, to a minimum thickness of 10-12mm When straightening, hollows should be filled out immediately before a skin is formed. Care should be taken to avoid small hollows, which can make it difficult to achieve a good finish. Small areas such as quoins, reveals and bands can be left with a plastic float finish. Do not polish.
Finish Coat Recommended Thicknesses
16mm: 1 Coat
10mm: 2 Coat Over base coat (Base coat recommended thicknesses above.)
SCRAPING
Scraping should take place when the render has set but not fully hardened. The exact timing varies according to weather conditions; can be anything from 4 to 36 hours after application. Typically, in moderate conditions, the render should be scraped the day after application. The render is ready for scraping when a thumb impression cannot be made but it can be marked with a thumb nail. At the correct time, the aggregate scrapes easily from the wall and does not stick to the scraping tool. Scraping should always be done lightly in a tight circular motion to produce a uniform finish. Remove only 1 - 2mm from the complete surface. All areas must be scraped at the same time.
K REND SILICONE TC
Please click here to download K Rend Silicone TC application instructions PDF.
First Coat: K Rend Basecoat
Preparation Coat: K Rend Primer TC
Final Coat: K Rend Silicone TC
Ensure that the background is clean, level and dry with no signs of efflorescence. We recommend newly applied basecoats are allowed a minimum of 14 days to cure.
Ensure all adjacent surfaces are well protected and masked. (Windows, sills, doors, floors, glass, brickwork etc.)
Application
Apply K Rend Primer TC (Colour matched to topcoat) by brush, roller or spray. Ensure that 24 hours drying time is allowed before the application of the topcoat.
Apply K Rend Silicone TC topcoat to the thickness of the largest grain size using a stainless steel float and allow to take up slightly. (This is only a few minutes.) The surface is then rubbed up in a circular motion using a plastic float to create a uniform texture.
Ensure that you complete full surfaces in a continuous motion without interruption. Maintain a wet edge at all times.
To avoid run off, protect freshly applied render from rain and drying too fast. Drying times will be prolonged, sometimes quite drastically, by low temperatures and/or high humidity.
MACHINE APPLICATION
The following K Rend products can be spray machine as well as hand applied; Silicone Spray E Grade, K1 Spray, K1 Silicone, Overcoating Silicone Dash, Silicone Spray Dash, Silicone Tyrolean, Standard UF Base, UF Fibre Base, HP12; HPX Base. M-Tec spray machines are available to purchase or rent from K Rend. A technical advisory service is also available.