FOR RENDERING BRICK, STONE, CONCRETE AND BREEZE BLOCK FIREPLACES
Vitcas Fireplace Render is a fine cement-like material which provides a protective rendering for vulnerable materials which can be damaged by exposure to heat. With a maximum temperature of 1400 oC(2552 F), it is more than adequate for these and other applications. Fireplace Render is a fully blended material with a maximum aggregate size of 5mm and is only to be mixed with water to a trowelling consistency. As a guide, the amount of water required is approx. 200ml per kilo.
New brickwork and surface: allow the backing material to dry fully before Vitcas Fireplace Render is applied.
Older surface: In order to provide maximum keying for Fireplace Render, rake out any mortar joints to a depth of about 12mm and roughen the brick or stonework with a sharp tool, where necessary. Brush away any loose material. Use clean tools and mix Fireplace Render with cold tap water to a stiff trowelling consistency. Dampen the surface slightly and apply with a trowel or float, working from the base upwards to give maximum support. For a free standing stove in a recess, the recommended thickness is 12mm on the surrounding walls and the back. For an open fire, log basket etc the recommended thickness is 25mm and this can be applied in one layer or in several layers as required. For the face of a chimney breast around a cassette stove (sometimes called inset or hole-in-the-wall), Vitcas Fireplace Render is used as a base coat for the Vitcas Heat Resistant Plaster finish coat. The thickness of this layer should be adjusted to suit the finishing layer of 3 – 6mm (1/8" - 1/4")
The surface should be floated as smooth as possible if the intention is to paint this surface later. If using as a base coat for Vitcas Heat Resistant Plaster then the surface should be left as a 'scratch coat' to provide a key for the plaster to adhere.
For all applications the freshly applied material should be first covered with a plastic sheet overnight and thereafter allowed to dry naturally for 48 hours.
COVERAGE: 20kg tub will cover approximately 0.35m2 (3.8 ft2) at a thickness of 25mm (1”)
PRE-HEATING: Pre-heating the render is necessary to dry out all the excess moisture which is retained within it. Failure to dry out this moisture before the render is subjected to high temperatures may result in the render failing and, in some severe cases, the build up of pressure could cause the render to shatter. For best results, pre-heat the render with a very hot electric fire or fan heater placed in the grate. Alternatively, light a paper and cardboard fire in the centre of the fireplace and try to keep the flames from touching the render. Maintain this pre-heat for a few hours, during which time a fire guard should be used. After pre-heating a conventional fire can be lit although a fire guard should still be used for the first 2 hours. Do not coat the Fireplace Render with any material until the pre-heat process and initial firing have been completed.
STORAGE: Keep any unused material dry and store in a cool dry place away from children and pets.