SELF-LEVELLING RENOVATION ROUGH FLOOR (from 5 mm to 30 mm)
UNDER TERRACOTTA, FLOOR COVERINGS AND WOOD FLOORING
FOR INTERNAL USE

USE

AVAL KN 78A is a self-levelling cement mass designed for machine or manual rough floors preparation under floor covering made of PVC, carpet, wood flooring, floor panels, terracotta, stone and natural marble. It can be used for repair and modernisation work as well as for new projects. It is recommended in case of levelling of existing substrates, even elevation of rough floor level in the whole room, evening levels of two different floors, and when surface irregularities prevent application of appropriate thickness of an adhesive. Substrates of this self-levelling mass can be made of concrete, cement and anhydrite bonded floors and `difficult surfaces` including vinyl, ceramic, PVC, natural stone or terrazzo substrates. AVAL KN 78 can be used for rough floor in the following arrangements: bonded to existing substrate (minimum layer thickness - 5 mm), on the separating layer (minimum layer thickness - 20 mm) or for levelling existing surfaces of heating unbonded floor. It is suitable only for interior use. Thickness of one layer, depending on selected solution, should be 5÷30 mm.

PROPERTIES

AVAL KN 78 is a dry mixture reinforced with fibre, containing mineral binders, fillers and new generation modifying agents. High elasticity and adhesion to various substrates as well as a wide range of underlayment layer thickness make it a general-purpose product. Easy mass preparation and its operating parameters (excellent fluidity and self-levelling ability) make it convenient to use. It ensures very even substrate characterised by excellent technical and operation parameters, facilitates preparation and increases standard of the final stage of finishing floor work. Optimum selection of setting time and quick increase of strength parameters make rough floor usable in a shorter period of time and ensure preparation of other work.

SUBSTRATE PREPARATION

The method of preparation depends on the arrangement in which AVAL KN 78 is to be used. In any case, the substrate should be stable and structurally sound. If rough floor is to be connected with substrate, the substrate should be free from anything that may impede adhesion, in particular dust, dirt, lime, oil, grease, wax, bitumen, paint, etc. Mechanically remove loose elements and parts of substrate of poor strength. If necessary, use one or two layers of AVAL KN 97 priming emulsion to reduce substrate`s excessive absorption. Before pouring out the mass, make additional marks on the walls to mark the location of expansion joints in the substrate that will be transferred to the rough floor. Due to the risk of underlayment outflow, the substrate should have a tank-like appearance. The technological fields and possibly floor openings should also be secured, so as to prevent outflow of the mass. This can be achieved by providing adequate profile with adhesive tape or wooden strips, using a bed of dry material as a seal. It is prepared on very weak, absorptive or oily mineral substrates or on other substrates that do not provide appropriate adhesion. The separation layer can be made of 0.2 mm thick polyethylene foil. The insulation should be placed tightly without creases and folded onto the walls (onto the expansion joint strips), at least up to the rough floor height. In case of substrates which are exposed to moisture, a vapour-resistant or anti-moisture insulation placed on the substrate may serve as the separation layer. Rough floor should be reinforced with a glass fibre mesh protected in acrylic bath and fixed to the substrate. In both cases, intermediate expansion joints are not required as the pouring surface of the rough floor does not exceed 20 m2. However, it is required to separate rough floor from walls using EXPANSION TAPE or thin strips of foamed polystyrene.

PRODUCT PREPARATION

In case of mechanical pouring, set appropriately the fixed level of dosed water in a mixing-pumping unit that ensures correct consistency of the mix flowing out from a hose. To check consistency, pour out the mass from a 1 l container onto even non-absorptive substrate (for example - foil). The compound should then form a `patch` of ca. 40 cm in diameter.. In case of manual pouring, prepare it by pouring dry compound into a container with suitable amount of water (in the ratio of 4.0÷4.5 l of water for 25 kg of container) and mix until homogenous. Do it mechanically; a drill with a mixer is recommended. The mass is ready to use immediately after mixing. It maintains its properties for 20 minutes. Inappropriate amount of water for mass preparation results in deterioration of strength parameters of the rough floor.

APPLICATION

First, it is necessary to determine the desired level and mark it on the walls and in the area where the mass is to be poured. This can be done e.g. using a level and height bench-marks. AVAL KN 78 may be poured mechanically, using in a mixing-pumping unit that enables continuous flow proportioning of water, but only on surfaces divided into technological fields that enable pouring within 45 minutes. Start pouring from the farthermost wall in relation to the exit Pour it in the form of approximately 50 cm wide belts parallel to the wall, paying attention not to step on the surface. Connect successive parts of the underlayment in at most 10 minutes. Initially distribute the poured mix using e.g. a smooth float made of metal. Rake up excess of the mass, thus controlling layer thickness. It is also recommended to de-aerate the mass using an wire mesh roller or a brush with hard long horsehair, moving the brush in shaking manner along and across the poured surface. This operation improves the spreading process and helps to obtain a more homogenous surface. Do not dilute the setting material. Protect the poured mass from drying too quickly, direct sunlight, low air humidity and draughts. Sudden changes in temperature are not allowed. Reduce heating of the room. The surface maintained in such a way is very hard and is characterised by low absorptivity. Expansion joints existing in the substrate should be copied on rough floor in the form of cuts. The drying time depends on the layer thickness and also thermal conditions and humidity in a given room. It is possible to begin underlayment use after about 6 hours. Ceramic and stone floor covering can be fixed after about 3 days, whereas carpeting, PVC, linoleum or wood flooring after about 7 days (depending on the humidity of the air and the substrate). The information comprises basic instructions of product application and do not relieve users of responsibility for work in accordance with good construction practice and OHS regulations.

CONSUMPTION

On average, ca. 20 kg of the mortar is used for 1 m2 for each 10 mm of the layer.

TOOLS

Mixing-pumping unit or slow-speed drill with mixer, wire mesh roller, brush with hard long horsehair, height bench-marks. Wash the tools with clean water directly after use. Clean the remainder of the set mortar that is difficult to remove with AVAL KL 55.

PACKAGING

Paper bags: 25 kg Pallet: 1050 kg in 25 kg bags

STORAGE & TRANSPORT

Store and transport in tightly closed bags, in dry conditions (pallets are particularly recommended). Keep dry. Shelf life in conditions complying with the requirements is 12 months from the date on the packaging.

CAUTION

Contains cement. Alkaline reaction with water – protect eyes and skin. In case of direct contact with eyes, seek medical attention.

TECHNICAL DATA

Mixing proportions: ca. 0.16÷0.18 l of water for 1 kg of mortar ca. 4.00÷4.50 l of water for 25 kg of mortar Pot life - ca. 20 minutes Temperature: mortar preparation temperature – from +5°C to +25°C Substrate and ambient temperature during work – from +5°C to +25°C Temperature resistance – from +5°C to +60°C Rough floor use – after ca. 6 hours. Average drying time - 1 week for 1 cm of rough floor thickness Max. aggregate diameter – 1.5 mm Min. layer thickness - 5 mm Max. layer thickness - 30 mm Content of soluble chromium (VI) in ready-to-use mix - ≤0.000% Cement-based rough floor Reaction to fire - A1fl class Corrosive substance release - CT Water permeability – NPD Water vapour permeability – NPD Compressive strength C35 (≥ 35 N/mm2) Flexural strength ≥ F7 (≥ 7 N/mm2) Abrasion resistance - NPD Sound insulation - NPD Sound absorbance NPD Thermal resistance - NPD Chemical resistance - NPD