Design Criteria

Vetotop AC441 should generally be applied in two coats to achieve a total dry film thickness of not less than 200 microns in order to accommodate substrate cracking up to 2 mm and cyclic movement up to 0.3 mm. It is possible to achieve the total dry film thickness in one coat however, this depends on the substrate type and the finish required. Trials are recommended prior to full application to ensure the finish meets the clients requirements. To achieve the correct protective properties, Vetotop AC441 must be applied on to the substrate at the coverage rates recommended. 

Priming
Vetoprime AP443 should be applied first. It should be applied in one or more coats until the recommended application rate of 0.4 litre per square metre has been achieved. This is best accomplished by using portable spray equipment. A uniform surface appearance (sheen) should be achieved.
The primer should be allowed to dry for a minimum of two hours (at 20°C) before overcoated with Vetotop AC441.

Application
In order to obtain the protective properties of the Vetotop AC411 system, it is important that the correct rates of application and overcoating times are observed.
Vetotop AC441 should be applied in two coats. First coat can be thinned with clean water depending on the substrate. Recoat time for second coat is two hours. If necessary, a third coat can be applied to achieve a hiding power.
It is important that no gaps or ‘raw edges’ appear in the finished coating. Special care should be taken to provide an unbroken coating at external corners and similar exposed protrusions.
Vetotop AC441 may be applied by the use of suitable brushes, rollers or airless spray equipment.

Cleaning
Vetotop AC441 should be removed from tools and equipment with clean water immediately after use.

All surfaces should be dry and free from any contamination and all traces of mould release oils and curing compounds. This is best achieved by lightly grit-blasting the surface. Where moss, algae or similar growths have occurred, treatment with a proprietary biocide should be carried out after the grit-blasting process.
Where application over existing sound coatings is required, trials should be conducted to ensure compatibility and retention of the bond between the underlying coating and the substrate. It is essential to produce an unbroken coating of Vetotop AC441. Surfaces containing blow-holes or areas of pitting should first be filled using Vetorep CR523 , a cementitious fairing coat. Rougher substrates can be levelled using a cementitious product from Saveto Concrete Repair Range.

• Vetotop AC441 is formulated for application to clean, sound concrete or masonry. Where application over existing sound coatings or paints is required, trials should be conducted to ensure compatibility and retention of the bond between the underlying coating and the substrate.
• Application of Vetotop AC441 should not commence if the temperature of the substrate is below 5°C.
  The product should not be applied in windy conditions where early-age dust adhesion may occur, or where rain is likely within 2 hours at 20°C or 20 hours at 5°C.
• The use of Vetotop AC441 should not be considered for areas subjected to exposure to ponded water. Vetotop AC442 should be considered in this occasion.