Drybase Universal Mortar

Application

Application For Drybase Universal Mortar

Preparation

Concrete Substrates

The substrate to be treated must be sound and even, open pored, roughened and its surface free from voids, large cracks or ridges. Any adhesion reducing substances like bitumen,
oil, grease, remains of paint or laitance must be removed
by suitable means, such as sandblasting, scabbling etc. Construction joints and shrinkage cracks exceeding 0.3 mm should be routed out to a minimum depth of 20 mm. Shutter tie holes should be roughened.

Water leaks must be stopped with Drybase Waterproof Plug. Thoroughly moisten the substrate. It must be damp but not wet at the time of application. Any surface water on horizontal surfaces must be removed.

Brick and Blockwork Substrates

Any remaining plaster, render or other substances that could inhibit bonding must be removed back to the substrate. Gypsum, remains of wood or other foreign material should be removed by appropriate means. Loose pointing must be routed out and the substrate cleaned thoroughly.

Water leaks must be stopped using Drybase Waterproof plug. thoroughly moisten the substrate. It must be damp but not
wet at the time of application. Any surface water on horizontal surfaces must be removed.

Mixing

Mix 25 kg of Drybase Universal Mortar with 3 – 4 litres of tap water in a clean container for at least 3 minutes to a lump- free, homogeneous consistency. Use a mechanical mixer.

Application

Drybase Universal Mortar is applied with trowel or suitable spray equipment. Apply a minimum of 6 mm (approx. 12 kg/m2) and a maximum of 12 mm (approx. 24 kg/m2) in one working cycle. For small areas such as coves, fillets, local repairs and shutter tie holes Drybase® Universal Mortar may be applied in layer thicknesses exceeding the above value.

Pour Drybase Universal Mortar over horizontal surface, then compact and strike off. After initial hardening it can be trowelled or given a ‘brushed’ finish to provide a non-skid quality.

Apply Drybase Universal Mortar to vertical surfaces like normal render. If several coats are required it is recommended to apply the next coat whilst the previous coat is still damp at the surface.

The waiting time before applying the following coat depends on local climatic conditions such as humidity, temperature, etc. The previous coat must be textured by suitable means (such as a soft brush) whilst still plastic to form a key.

To maintain workability of the material do not add water, simply re-stir the mixture.

Do not apply at temperatures below 5 °C, or to a frozen substrate.

Trowel Application

Apply a scratch coat first for maximum adhesion to the substrate. Ensure that all cavities in the substrate are filled in order to exclude any trapped air.

Spray Application

Drybase Universal Mortar can be applied with a suitable mortar spraying device. For maximum spray pattern it should be possible to adjust volume of product as well as air pressure and volume.

The nozzle diameter is approx. 10 mm. The first layer of Drybase Universal Mortar is applied in a circular motion with the spray nozzle held at a 90° angle to the substrate. The material is then flattened and trowelled or keyed for a further layer.

Curing

Keep damp for at least 5 days and provide suitable protection against extreme weather conditions (e.g. sun, wind, frost) while setting. The freshly treated surfaces should be protected from rain for a minimum period of 24 hours.

Plastering/Coating

Surfaces treated with Drybase products which are to be coated or painted should be left to cure for 4 weeks. When a plaster or render finish is required on top of a Drybase treatment it is essential to apply a rough cast of sand and cement on the final Drybase coat while it is still tacky. On hardened Drybase surfaces apply an appropriate bonding agent, such as SBR before rendering. Coatings on top of a Drybase treatment have to be alkali resistant. Decorative coatings applied on the negative water pressure side should be water vapour permeable.