PLASTERING MIXES
ATLAS CEMENT SCRATCH COAT
scratch coat for 2- or 3- coat plasterwork
• improves plaster adhesion to substrate
• recommended for cement and cement-lime plasters
• reduces the material cost of plasterwork
• the highest strength category
• manual or machine application
PRODUCT CONFORMS WITH
THE EUROPEAN
STANDARD
„„ Use
„„ Technical data
Creates adhesion layer in two- or three-coat plaster systems – applied directly to the
substrate before the application of top coat of cement or lime-cement plaster.
Excellent compatibility with ATLAS plastering mortars:
-- PLASTERING MORTAR,
-- LIGHTWEIGHT CEMENT-LIME PLASTER
-- KB-TYNK
Reduces the cost of two- or three-coat plasterwork – replaces more expensive plaster
types at the scratch coat stage.
Hand or machine applied – the use of plastering units speeds up the application
considerably.
ATLAS CEMENT SCRATCH COAT is manufactured in the form of dry mix
of highest quality cement binder, quartz fillers and modifiers improving
the plasticity and workability of the material.
Types of substrates – walls and ceilings of bricks, blocks, hollow blocks and other
similar ceramic or silicate elements; concrete and aerated concrete; cement-bonded
particleboard, cement and cement-lime plasters.
„„ Properties
High strength – the highest standard-specified strength class CS IV (above
6.0 N/mm²) – the scratch coat is a suitable base for top coats, even those of high strength
plastering mortars, as it is resistant to shrinkage stress occurring during the setting of
mortars of that type.
Excellent adhesion to substrate – especially recommended for smooth surfaces or
substrates of low absorption capacity; bonds strongly to bricks, blocks etc.
The mortar can be supplemented with so-called anti-frost additives allowing to
carry out works at lowered temperatures, i.e. below +5°C – the new temperature
range of mortar application, the way of its preparation (especially the adjustment of
the amount of water added), principles of carrying out works and the mortar setting
conditions must be accepted according to the guidelines of the manufacturer of the
additive. The amount of the anti-frost agent depends on the content of cement in the
mortar – the proportion of cement to fillers in ATLAS SCRATCH COAT is at 1:4.
Note. The manufacturer of the mortar is in no way responsible for the effects and the
quality of the anti-frost agents used.
150
CLASS OF REACTION TO FIRE ACC. TO
THE EUROPEAN
STANDARD
www.atlas.com.pl
Bulk density (of dry mix)
ca. 1.57 kg / dm³
Wet density (after mixing)
ca. 2.06 kg / dm³
Dry density (after setting)
ca. 1.6 kg / dm³
Mixing proportions
water / dry mix
0.22 l / 1 kg
Scratch coat thickness
ca. 4 mm
Mortar preparation temperature,
substrate and ambient temperature
during work
from +5°C to +25°C
Maturing time
ca. 5 minutes
Pot life
ca. 2 hours
ca. 6.5 l / 30 kg
„„ Technical requirements
ATLAS CEMENT SCRATCH COAT conforms to PN-EN 998-1 standard. EC
Declaration of Performance No. 111/CPR.
PN-EN 998-1:2012
(EN 998-1:2010)
Factory made plastering mortar of specified
properties, general-purpose (GP)
For indoor and
outdoor use
Compressive strength
≥ 6.0 N/mm²
Reaction to fire - class
A1
Water absorption
≤ 0.40 kg/m2 min0,5
Adhesion
0.5 N/mm² - FP:B
Water-vapour permeability coefficient
μ 22
Thermal conductivity coefficient
(average tabular value P=50%)
0.83 W/mK (λ10, dry)
Durability. Compressive strength decrease after
freeze-thaw cycles
< 10 %
Durability. Mass decrement after freeze-thaw
cycles
≤ 3%
Dry bulk density
≤1800 kg/m³
Content of hazardous substances
See: Material Safety
Data Sheet (MSDS)
PLASTERING MIXES
„„ Application
Substrate preparation
The substrate should be dry, stable, flat and capable of load bearing, i.e. sufficiently
sound, and cleaned of materials that might affect mortar adhesion, especially dust, dirt,
lime, oil, grease, wax, residues of release agents or paint. Insufficiently bound substrate
fragments should be hammered off, whereas all loose or crumbling particles should
be removed using a steel wire brush. Contacting edges of particleboards should be
reinforced prior to plastering using strips of stainless steel mesh. Corners and edges of
window and door reveals should be protected using galvanised steel corner profiles. If
necessary, substrates characterised by excessive absorption capacity should be primed
with ATLAS UNI-GRUNT emulsion.
Mortar preparation
Pour the mortar from the bag into a clean container with the suitable amount of water
(see Technical Data for proportions) and mix using a drill with a mixer (or in cement
mixer) until homogenous. In the case of machine application - in a plastering unit. Leave
the mortar to rest for 5 minutes and then remix. The mortar is ready to use directly after
mixing and should be used up within ca. 2 hours.
Application of scratch coat
The mortar is applied to the prepared substrate manually or mechanically, in a uniform
coat, to the thickness of ca. 4 mm. Do not smooth or float the material. Leave the mortar
to set initially (ca. 12 hours). After initial mortar setting the top plaster coat can be applied.
Maintenance
Ensure appropriate room ventilation during drying. Protect external plasters from drying too quickly.
„„ Consumption
Material consumption depends on the accuracy of surface covering.
In the case of scratch coat covering the entire surface the material
consumption is ca. 8 kg of dry mix for 1 m2.
„„ Important additional information
• Adjust the ratio of added water experimentally, following the desired
consistency of the mortar, type of substrate and weather conditions.
Inappropriate amount of water for mix preparation results in deterioration of strength parameters of the scratch coat.
• Tools must be cleaned with clean water directly after use. Difficult to
remove residues of the set mortar can be removed with the ATLAS
SZOP agent.
• Irritant - contains cement. Irritating to respiratory system and skin. Risk
of serious damage to eyes. May cause sensitisation by skin contact.
Due to its form - powder, the product may cause mechanical irritation
of eyes and respiratory system. Keep out of reach of children. Do not
breathe dust. In case of contact with eyes, rinse immediately with
plenty of water and seek medical advice. Wear suitable protective
clothing, gloves and eye/face protection. If swallowed, seek medical advice immediately and show the container or label. Follow the
instructions in the Material Safety Data Sheet.
• The mortar must be transported and stored in tightly sealed bags, in
dry conditions (most preferably on pallets). Protect against humidity.
Shelf life in conditions as specified is 12 months from the production
date shown on the packaging. Content of soluble chromium (VI) in
ready-to-use mix - ≤ 0.0002%.
„„ Packaging
Paper bags: 30 kg
Pallet: 1080 kg in 30 kg bags
The above information constitutes basic guidelines for the application
of the product and does not release the user from the obligation of
carrying out works according to engineering principles and OHS
regulations.
At the time of publication of this product data sheet all previous
ones become void.
Date of update: 2013-09-19
Product Data Sheets Catalogue
151