weber.rend OCR is a range of proprietary renders based on Portland cement, lime and sand. They are supplied as pre-blended dry powders, which require only the addition of clean water to provide a comprehensive range of renders which comply with the mix designations and specifications of BS 5262 and BS 5492. A lime-free version for tiling, which conforms to the requirements of BS 5385 is also available.
Formulated to comply with British Standard mix designations (see technical data)
Resists the penetration of external water and has excellent weather resistance and durability, whilst allowing the structure to breathe
Factory controlled production to give a consistently high quality product
Give the same final appearance as traditional cement and sand renders but in significantly less time
Non-combustible (Class 0 fire rating when applied to non-combustible substrates)
All surfaces must be sound, clean, dry and free of any material which may impair adhesion.
Scaffolding must be independently tied to allow for uninterrupted application. Any faults in the structure, particularly those which may lead to moisture penetration must be rectified.
Poorly keyed surfaces, for example smooth concrete, or substrates of uneven or high suction should be prepared with weber.rend aid.
Mask around the areas where material is to be applied. Masking tape must be removed before the material has dried out.
Expansion joints should be included as required by the substrate and carried through all applied materials.
Suitable specification clauses, including specifications for difficult or mixed substrates are available from our Technical Services Department.
Note: In many cases rendering applied to expanded metal lathing is more prone to cracking than when applied to dense masonry. To reduce this risk, lathing must be fixed strictly in accordance with the manufacturer's recommendations and relevant codes of practice.
weber.rend OCR should be mixed with clean water at a rate of approximately 4 - 5 litres per 25 kg bag using a tumble mixer or suitable drill with whisk attachment. For best results, use as little water as possible and mix to give a workable consistency.
Note: weber.rend OCR may stiffen on standing. Re-mix product to regain workable consistency but do not add any more water.
To avoid dampness and discolouration of finishes rendering should be avoided below DPC or within 150 mm of ground level.
weber.rend OCR should be applied with a hawk and trowel in a one coat operation, then ruled level. On low suction backgrounds a first pass may be necessary prior to building up the full thickness in the second pass.
Render thicknesses are as for traditional materials.
External render approx. 16 mm for sheltered to moderate exposure or 20 mm for severe exposure.
Internal render approx. 8 to 19 mm.
Tiling approx. 8 to 20 mm.
Thickness should not exceed 25 mm.
Finish as required. For plain face finishes rub up in the normal way as the render begins to pick up. Other appropriate fishes may be achieved by suitable means.
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
