weber.rendaid 

Preparatory key coat for rendering

• To achieve a good key for rendering onto smooth or otherwise unsuitable but sound surfaces
• Ideal as a pre-treatment for renderings required to resist severe exposure conditions
• Suitable substrates:
  dense concrete
  brickwork
  blockwork
  masonry
  clean, sound, well adhered
  existing render (<19mm)

• Equalises suction on mixed backgrounds
• Provides excellent suction control across both high and low suction substrates
• Resists the penetration of external water to improve the weather resistance of rendering systems
• Quality controlled and factory blended to give a consistently high quality product
• Easy to apply by hawk and trowel and/or roller

Proprietary mix, designed to be used as an adhesive stipple pre-treatment as described in BS 5262. Can be supplied based on sulphate-resisting cement for use in common bricks.

Suitable specification clauses for dealing successfully with most types of substrates are available from our Technical Services Department.

BS 5262, Code of practice for external renderings, and BS 8000-10, Workmanship on building sites. Code of practice for plastering and rendering should be followed at all times.

Do not apply to gypsum plaster or previously painted surfaces.

For applications where the codes of practice recommend sulphate resistance, use only the sulphate-resistant cement formulation.

Mix three parts of weber.rend aid with one part of clean water in a clean container, using a suitable drill with whisk attachment. For smaller quantities a hand whisk may be used.

After mixing, leave to stand for approximately 5 minutes before remixing to a workable consistency, adding more water if necessary.

With a hawk and trowel or an open hopper spray gun, apply a tight layer 2 - 3 mm thick to the substrate. Texture the surface using a roller or by thoroughly raking with a proprietary render comb. If preferred, weber.rend aid may be applied and stippled in a single operation, with a well loaded roller.
Apply no more than 2 - 3 m2 before texturing.

It is important that the final texture achieved should be a deep, heavy stipple finish with a textured depth of 5 - 10 mm.

For difficult substrates, such as those with low suction or those retaining dust after cleaning, scrub weber.rend aid well into the surface with a small hand brush and then texture with the brush or roller.

Cure for 2 - 3 days before over coating.

During rapid drying conditions such as hot climates, curing with a fine spray of clean water may be necessary.

Protection
Protect from unfavourable weather conditions during application and early curing.

Good practice

Do not apply:

• If frost is forecast within 24 hours of use
• In damp/wet conditions
• In temperatures below 5°C or above 30°C
• On elevations in direct sunlight or where the substrate is hot

Keep equipment clean by washing frequently during application and wash immediately after use with clean water. Do not dispose of waste material into drainage systems.

For each mm of thickness, you will require approximately 1.4 kg per m2. When trowel applied to a thickness of 2 - 3 mm, coverage is approximately 7.5m2 per 25 kg bag.

Note: These estimates take no account of wastage and will vary according to the type of substrate. Allowance must be made for extra material required on high suction or uneven substrates.

When stored unopened in a dry place at temperatures above 5°C, shelf life is 12 months from date of manufacture.

Contains cement (Contains chromium (VI). May produce an allergic reaction). Harmful by inhalation. Irritating to eyes and skin. Keep out of the reach of children. In case of contact with eyes, rinse immediately with plenty of water and seek medical help. After contact with skin, wash immediately with plenty of soap and water. Wear suitable protective clothing, gloves and eye/face protection.

For further information, please request the Material Safety Data Sheet for this product.

weber's Customer Services Department has a team of experienced advisors available to provide on-site advice both at the specification stage and during application. Detailed specifications can be provided for specific projects or more general works. Site visits and on-site demonstrations can be arranged on request.

Technical helpline
Tel: (01525) 722110
Fax: (01525) 718988

Sales, England and Wales
Tel: (01525) 722100
Fax: (01525) 718988

Sales, Scotland
Tel: (0141) 445 0121
Fax: (0141) 445 0122

Sales, Ireland
Tel: (028) 9335 2999
Fax: (028) 9332 3232