About this product
weber.tec latex is a water-based dispersion of SBR polymer which has been specially formulated to meet the requirements of the construction industry.
Incorporation of weber.tec latex into cementitious mixes improves the overall performance of the final product with respect to strength, adhesion and durability. In use, the latex is blended with cement and suitable aggregates so that a reinforcing polymer is deposited in the micro-voids normally found in cementitious products. By carefully varying the proportions of latex, cement, sand and water, a whole range of useful bonding slurries, adhesives and mortars are produced
Features and Benefits
- Improved tensile, flexural and compressive strength
- Excellent adhesion characteristics
- Improved chemical resistance
- Increased resistance to water and water vapour penetration
- Improved resistance to freeze/thaw
- Reduced shrinkage and shrinkage cracking
- Improved workability
- Can be used in contact with potable water
- Listed by UK Water Fittings By-law Scheme
Technical data
Preparation
Concrete
Concrete substrates must be adequately prepared either by a suitable mechanical method, such as scabbling, grit blasting or needle gunning, or by such other means as appropriate. Concrete bases for toppings must be carefully prepared to give a clean, freshly-exposed surface.
Old concrete surfaces contaminated with oil or grease require suitable preparation such as steam cleaning in conjunction with a suitable detergent. Care must be taken to ensure that the oil or grease is removed from the surface and not simply spread over a larger area. New concrete should be cured for at least 14 days using an approved curing technique. Spray-on curing membranes are unsuitable for use on substrates where weber.tec latex mixes are to be applied.
Steel
Steel reinforcement which has been exposed during preparation should be completely uncovered to the full circumferance of the bar. Rust scale, corrosion products and other deposits must be removed from reinforcement by grit blasting or other approved methods to achieve first quality to BS 7079-A1 (equivalent to Swedish Standard SA 21/2). Steel cleaning shall include hidden faces at the back of bars and at intersections, and a bonding agent/holding primer applied immediately after.
In many instances where chloride-induced corrosion is absent, and where grit blasting is not practical, wire brushing or other techniques may be acceptable to the engineer, provided that care is taken not to polish the surfaces of the rust on the stee
Application
Slurry bondcoat
Surfaces must be thoroughly dampened prior to application and excess water removed.
Using approximately two volumes of cement and one volume of weber.tec latex, mix to a smooth, creamy consistency adding extra water if required (up to 1 volume). The mixed material has a workable life of 1 - 2 hours in the bucket depending on temperature and type of cement. Apply by stiff brush or broom, working it well into the surface. Under no circumstances must the slurry be allowed to dry before the new mortar is placed. If large areas of topping are to be laid, the slurry should be applied just in advance of laying. If the Slurry Bondcoat does dry, it should be mechanically removed and the repair procedure restarted.
Tile, mosaic and brick slip adhesive A water-resistant adhesive suitable for areas such as swimming pools, showers etc. where tiling is continually subjected to water splashes, can be prepared from one of the following mixes according to thickness required.First blend 5 litres of clean water with the latex then add the cement and sand. A little water can be added to bring the mix to the right consistency but do not over water.
Apply to the substrate spreading to the desired thickness with a float. For thin bed application, rib with a tiler's notched trowel to produce ribs 6 mm square at 25 mm centres then press the tile on to the adhesive and ensure good contact (80%) on the back of the tile. For thick bed applications, press the tiles straight on to the spread adhesive and bed down with a wooden float. Tiles can be buttered with the adhesive 3 mm thick if this method of application is preferred. Do not wet tiles or substrate. Leave 24 hours to set hard. Grouting may be carried out using a thin bed mix, but wipe any excess off the tiles before it sets.
Concrete repair and bedding mortar, screed and render
A water resistant mortar for concrete repairs, the bedding of bricks and tiles and rendering can be produced from the following mix:First blend the water with the latex then add the cement, sand and chippings. A forced-action mixer, e.g. Creteangle, is recommended. The topping should be laid on to a single coat application of Slurry Bondcoat which is still tacky. The recommended thickness for the topping is 10 - 12 mm. The mix may appear dry but when compacted and finished with a steel float the surface should close up without giving a heavy skin. A trial is recommended before commencing the main application.
First blend the water with the latex and then mix in the cement and sand. A minimum quantity of water should be added to bring the mix to the correct consistency. Concrete repairs can be effected to floors, walls and soffits. On vertical and overhead applications it is essential to build up in layers approx. 6 mm thick. All surfaces should be primed with Slurry Bondcoat. The minimum thickness for repair and to cover steel reinforcement is 12 mm. For thinner sections use weber.tec mortar or weber.tec EP mortar. Where it is necessary to blend in around edges 'toeing in' is recommended (i.e. cutting back to increase thickness). The bedding of bricks and floor tiles can be achieved with a thickness of 6 mm.
A water-resistant render is also produced from this mix. Apply one coat of Slurry Bondcoat and whilst still tacky apply the render in two applications each about 6 mm thick. For a waterproof render use weber.cem dryrend 521.
Heavy duty floor topping
weber.tec latex may be incorporated into screeds or granolithic toppings suitable for industrial use.
Precautions
Do not dilute weber.tec latex beyond the quoted recommendations and allow for any water content in the sands used. Do not use water which has dissolved salt content. Surplus adhesive should be removed from tools etc. with water before it sets. weber.tec latex mixes should not be applied when conditions are not suitable for good concreting practice. In particular do not apply below 5°C.
Curing
Correct curing procedures must be adopted, especially in hot, dry conditions or in areas exposed to drying winds. It is recommended that repair mortars, renders and screeds are cured with weber.tec ritecure sprayed at a rate of 5m² per litre, unless the surface is to be subject to subsequent treatments such as tiling or painting. An alternative method is to cover with overlapping polythene sheets for at least 48 hours at 20°C.
Storage and Shelf life
Replace the lid after use and store in a cool dry place.
Protect from frost.
Health and Safety
Essentially not hazardous.
Not harmful during normal use. After contact with skin, wash immediately with plenty of water. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. Keep out of the reach of children.
For further information, refer to the Weber Safe Handling Guide.
Technical services
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 Contact
weber products are distributed throughout the UK through selected stockists and distributors. For UK sales enquiries and overseas projects, contact Weber's Sales office.
Sales office
Tel: (01525) 722100
Fax: (01525) 718988
More Information
Packaging
weber.tec latex is supplied in 5, 25 and 200 litre non-returnable containers.
weber recommends 10 litres Latex per 50 kg cement in the mix design. The approximate quantities required of weber.tec latex per m for various applications are as follows:
Slurry Bondcoat: 0·3 litres
Thin Bed Tile Adhesive ribbed: 0·2 litres
3 mm Bed Tile Adhesive continuous: 0·6 litres
6 mm Bed Tile Adhesive: 1·2 litres
12 mm thick Repair Mortar/Flooring: 1·5 litres
NB. These figures must be checked by the contractor prior to ordering.
