Description

One component, polymer modified cementitious filler & reprofiling mortar

Uses

Renderoc BF is designed for application to imperfections in concrete and masonry surfaces.

It is suitable for application in the range 0 to 5 mm, and can be used in the following situations:

• Filling blow holes prior to overcoating
• Skim-coat over concrete to receive protective coatings
• General reprofiling over large areas
• Reprofiling, in association with other Renderoc mortars

Advantages

• Cost effective/time saving – no independent primer or curing agents required
• High performance – excellent bond to substrate
• User friendly – requires addition of water only
• Suitable to receive protective coatings

Description

Renderoc BF is supplied as a ready to use blend of dry powders and polymers, which requires only the addition of water to produce a highly consistent cementitious mortar, with good handling characteristics.

Renderoc BF exhibits excellent thermal compatibility with concrete and is fully compatible with other Renderoc* mortars and Dekguard* protective coatings.

Properties

The following results were obtained at a water:powder ratio of 0.2

		@ 20°C	@ 35°C
Working life (Approx.)	:	45 minutes	20 minutes
Setting time (BS 5075)	:	60 minutes	45 minutes
Fresh wet density	:	1840 kg/m3
Compressive strength (ASTM C109)	: : :	3 days – 15 N/mm2 7 days – 25 N/mm2 28 days – 40 N/mm2
Coefficient of thermal expansion	:	7 to 12 × 10-6/°C

Note: Working life and setting time will vary dependent on ambient, substrate temperatures and wind speed.

Design criteria

Renderoc BF is designed for vertical and overhead use to infill surface imperfections of concrete in the range 0 to 5 mm.

Instructions for use

Preparation

Clean the surface and remove any dust, unsound material, plaster, oil, paint, grease, corrosion deposits or algae.

Roughen the surface to remove any laitance and expose the fine aggregate by light scabbling or sweep blasting.

Oil and grease deposits should be removed by steam cleaning, detergent scrubbing or the use of a proprietary degreaser.

The effectiveness of decontamination should then be assessed by a pull-off test.

The cleaned areas should be blown clean with oil-free compressed air before continuing.

All prepared areas should be thoroughly soaked with clean water immediately prior to the application of Renderoc BF.

Any residual surface water should be removed prior to commencement.

Mixing

Care should be taken to ensure that Renderoc BF is thoroughly mixed. In all cases the powder component should be introduced into water.

Mixing should be carried out in a suitably sized mixing vessel, using a slow speed (400/500 rpm), heavy duty drill and a Fosroc mortar mixing paddle.

Place 4 – 6 litres of water (depending of workability) into the mixer and, with the machine in operation, add one full 20 kg bag of powder, then mix for 3 to 5 minutes, until fully homogeneous.

Do not use more than 6 litres of water per 20 kg bag.

Application

Apply the mixed Renderoc BF to the blow holes by steel trowel.

It should be applied with minimum working and be allowed to partly set before finally troweling to a smooth finish.

If a very smooth finish is required, a small amount of water may be flicked on to the surface of the Renderoc BF with a paint brush prior to final troweling.

Renderoc BFÖ

Curing

Curing is not generally required. However, under extreme conditions – high temperatures and drying winds – use Nitobond AR*h or Nitocote PE135*h, as a curing agent, or cover the surface with polythene sheeting, taped down at the edges.

Nitobond AR does not require mechanical removal prior to overcoating with Dekguard system.

If overcoating with epoxy or polyurethanes then use Nitocote PE135 as the curing membrane.

Cleaning

Renderoc BF should be removed from tools, equipment and mixers with clean water immediately after use.

Cured material can only be removed mechanically.

Overcoating with protective/decorative finishes

Renderoc BF may be overcoated after 48 hours, in ambient conditions of up to 75% relative humidity dependant on the type of coating.

For further information consult the local Fosroc office before proceeding.

Limitations

• Renderoc BF should not be used when the temperature is below 5°C and falling
• Do not proceed with the application when rainfall is imminent unless in a sheltered or protected situation

If any doubts arise concerning temperature or substrate conditions, consult the local Fosroc office

High temperature working

At ambient temperatures above 35°C, the components should be placed in air-conditioned storage of less than 25°C, for special application procedures, refer to your local Fosroc office.

Estimating

Supply                                                                   

Renderoc BF                       : 20 kg bag

Yield                                                                      

Renderoc BF                       : 13.5 litres per 20 kg bag (based on 6 litre water)

Actual coverage of Renderoc BF will be wholly dependent upon the general substrate condition. It is recommended, therefore, that site trials over a typical area are carried out to determine actual usage.

Storage

All products have a shelf life of 12 months if kept in a dry store in the original, unopened bags or packs @ 25°C. If stored at high temperatures and/or high humidity conditions the shelf life may be considerably reduced to 4 – 6 months.

Precautions

Health and safety

Renderoc BF contains cement powders which, when mixed or become damp, release alkalis which can be harmful to the skin. During use, avoid inhalation of dust and contact with skin and eyes. Wear suitable protective clothing, gloves, eye protection & respiratory protective equipment.

The use of barrier creams provides additional skin protection. In case of contact with skin, rinse with plenty of clean water, then cleanse with soap and water.

In case of contact with eyes, rinse immediately with plenty of clean water and seek medical advice. If swallowed, seek medical attention immediately – do not induce vomiting.

For further information, refer to the Product Material Safety Data Sheet.

Fire

Renderoc BF is a non-flammable product.