webercem fairing coat

Preparation

webercem fairing coat is suitable for use on concrete and dense concrete blockwork.

All substrates must be sound, free of all contamination including laitance, paints, coatings, oil, grease and dust.

Concrete and concrete blockwork surfaces must be adequately prepared by use of suitable mechanical means such as grit blasting, high pressure water jetting or needle gunning to produce a lightly textured surface to ensure a good key.

Concrete surfaces contaminated with oil or grease require suitable preparation. New concrete must be fully cured for at least 14 days. Do not use a permanent curing membrane.

Defects such as honeycombing, leaks, pinholes, cracks etc. should be treated appropriately prior to the application of webercem fairing coat. Pinholes, blowholes, small voids and pores can be treated with webercem fairing coat as described below. Cure fresh repairs for at least 24 hours.

Thoroughly dampen the area to be treated with clean water and allow excess to drain off before applying webercem fairing coat.

Mixing

Mix webercem fairing coat in a forced-action mixer or in a clean bucket using a paddle and a slow speed drill at a speed not exceeding 400rpm. Mix for at least 2 minutes to a smooth and homogenous paste consistency. For normal levelling applications use 3 to 3.5 litres of water per 25 kg bag. For other applications such as pore filling, dubbing out, etc. the water addition can be varied depending on the consistency required and the ambient temperature.

Min. water addition: 3 litres per 25 kg bag Max. water addition: 3.5 litres per25 kg bag. Usable time after re-mixing: > 45 minutes. For small quantities, mix 1 part water to 4.5 parts of powder by volume.

Application

Ensure all pores, surface voids etc. are filled first before applying webercem fairing coat as a levelling mortar.

For pore filling:

Use a pallette knife or similar tool to apply the mortar, pressing well into the pores. Alternatively, use a damp sponge to rub the mortar into the pores with a circular motion. Finish flush to the surface and rub off any excess mortar. It is best to allow the pore-filling mortar to harden first before re-wetting and applying the levelling coat.
Maximum depth and diameter of application: 5mm

For surface levelling:

Apply with a steel float to a thickness of about 2 mm pressing well into the damp substrate. lf a thicker coat is needed to hide deeper surface imperfections, apply the second coat when the mortar has hardened sufficiently to support it. 
Minimum thickness of application: 1mm per layer.
Maximum thickness of application: 3mm per layer up to a combined maximum of 5mm.

A spray pump can be used when levelling large areas of concrete.

Use a steel float to provide a smooth surface when the mortar has firmed up sufficiently. Do not re-wet the surface before trowelling. This may cause some surface crazing.

Alternatively, rub up with a wooden float or sponge to produce a level surface suitable for overcoating.

Curing

Normal concrete curing methods are recommended. Do not use a curing agent when applying a coating unless it can be proven that the subsequent bond will be unimpaired.

webercem fairing coat can be overcoated by one of the anti-carbonation coatings in the webercote range. Overcoating times are dependent on weather conditions.

Temperature range of application: +5°C to +35°C. Do not apply on frozen surfaces or when frost is expected within 24 hours. Do not apply in direct sunlight or on hot substrates.

When applying in confined or close spaces, cure for 3 days then ensure sufficient ventilation to prevent condensation.

Note: Times quoted need to be extended at lower temperatures and reduced at higher temperatures.

Yield

Actual yield depends on the water mix ratio.
Approx 3.8kg per m2 when applied at 2mm thickness.
Approx. 6.5m2 per 25kg at 2mm.
Yield approx. 13 litres.