The information contained in this manual will assure that the mosaics produced by CVS ITALIA S.R.L. (made from a mixture of ground marble and resin) are correctly installed.
PRELIMINARY VERIFICATION OF THE LAYING SURFACE
Before proceeding with the installation, please check that the laying surface possesses the following characteristics:
SMOOTHNESS
It is fundamental that the laying surface will be absolutely smooth and flat. For these 6 mm thick mosaics, surface irregularities must not exceed +/- 1.5 mm. Slight unevenness can be corrected using the adhesive itself as a levelling agent, while more pronounced irregularities (> 5 mm) will need to be corrected using a levelling cement-based grout.
MAXIMUM CURING AND HUMIDITY LEVELS
Regardless of what kind of substrate you are dealing with, the ageing process must be completed before installing the mosaics, to assure that it is stable and it will not shrink after the mosaic sheets have been laid. When using traditional cementitious screeds, curing time can vary from 7 up to 10 days each centimeter of thickness, depending on the season.
Waiting time can be shortened by using special, normal-hold, quick-drying hydraulic adhesives rather than Portland cement, thus allowing mosaics to be laid after 24 hours only. For this kind of substrate, humidity levels must not exceed 3%.
In case of concrete surfaces, curing takes at least 6 months.
Maximum residual humidity in gypsum-based substrates, such as anhydrite screeds or gypsum plasters, must not exceed 0.5%. In case of premixed, cement-based plasters, please abide by the manufacturer’s indications, with regards to curing, drying times and mechanical resistance.
SUBSTRATES CLEANING
Substrates must always be perfectly clean and smooth, with no chipping or traces of paint, wax, grease, oils or anything else that could compromise the adhesive properties of the binding agent. Concrete substrates must not have any residue of release agents.
It is always advisable to preventively clean the surfaces with a hot-water jet-spray cleaner or with a sandblasting machine. Ceramic-tiled surfaces must be thoroughly de-greased with an alkaline detergent or with a caustic soda solution and then rinsed and dried.
MECHANICAL RESISTANCE
Regarding cement-based or gypsum-based plaster applied to an internal wall, it must have an adhesion to the substrate of at least 0.5 N/mm2. In case of external wall application on plaster, make sure that the plaster itself is suitable for mosaics.
To ensure a good adhesion, the surface of the substrate must not generate powders. Suitable consolidating primers in dispersion can be used to improve this feature.
INSTALLATION GUIDE
After having chosen the appropriate adhesive and prepared the mixture according to the indications on the package or technical data sheet, it is advisable to apply the adhesive mortar to the laying surface with the smooth edge of the trowel, to even the colours, and then immediately after apply the other product by means of a 3.5 mm (cod. 121/D 3.5x3.5) notched trowel. Install the mosaic sheets, tapping them into place with a rubber trowel (COD. 946GR) to guarantee perfect adhesion, thus eliminating air bubbles and keeping the adhesive from flowing back into the joints between the tiles, make sure to leave sufficient space for subsequent grouting.
HAMMAM INSTALLATION
The hammam or Turkish bath is a prominent feature in wellness programs, where people relax in extremely humid, warm-to-hot rooms (from 30°C to 60°C).
The interiors of these structures often consist in prefabricated panels or forms (benches, beds, niches, etc.) made of expanded polystyrene covered with impermeable material to which mosaics may be directly applied. Here again adhesives should be used, and grouting made exclusively with epoxy grout.
INSTALLATION IN WET AREAS (BATHROOMS AND SHOWER CABINETS)
Installation in wet areas such as bathrooms or shower stalls requires the use of the two-component epoxy-polyurethane adhesive or of the two-component epoxy grout.
Subsequent grouting should be done using epoxy grout.
GROUTING
Before grouting the joints, it is essential to verify that the adhesive used in the installation process is completely dry and hard and that also the joints are perfectly dry. At this point, manually remove any residual adhesive that may have leaked into the joints.
CVS ITALIA S.R.L. recommends the grouting of its mosaics with epoxy grout, because it guarantees the following advantages:
- Bright, uniform colour
- Particularly wide range of colours choice
- Practically zero water absorption
- Extremely easy to apply and clean
- Highly durable joints for long-lasting results
CAUTION:
1. Always carefully follow the indications on the package or technical data sheet given by producers.
2. Make sure that work site conditions are suitable for mosaic installation.
HOW MUCH ADHESIVE AND GROUT SHOULD BE USED
The quantity of adhesive indicated here refers to applications using a notched 3.5x3.5 mm (cod. 121/D 3.5x3.5) mosaics trowel.