Surface preparation
If the finished floor is required to be flat, a level survey should be carried out to determine the areas that require filling out and high spots to be removed, so that an estimate of the amount of MASTERTOP 1240 PLUS that will be required for the job can be made.
The concrete surface to which the MASTERTOP 1240 PLUS will be applied should be structurally sound, with all major defects repaired before the surface is scarified.
Low spots can be filled using MASTERTOP 1240 PLUS or Concresive 2200 in which case the areas to be filled should first be primed with MASTERTOP 1240 PLUS Primer.
Light oil and grease deposits should be removed with a degreasing solution. Heavy oil deposits should be removed by hot compressed air followed by the application of CONCRESIVE 1020 to impregnate the heat treated floor.
If proper hot compressed air equipment is not available, a propane gas torch can be used to heat the concrete and drive out the deep seated oil. Care must be taken when using this method, to heat the concrete up slowly. Keeping the torch trained on one spot to effect a rapid heat build up will cause the concrete to spall violently.
Always remove oil and grease deposits before starting any other form of preparation.
The preferred methods of preparation are mechanical, such as captive blasting, planer scarifiers or scabbling. When the mechanical preparation is complete, remove all dust and debris, preferably by a vacuum cleaner to leave a clean, dust free surface.
Priming
MASTERTOP 1240 PLUS is laid into wet or tacky primer. Use MASTERTOP 1240 PLUS Primer.
Mix the base and reactor components of the primer together until all striations have disappeared.
Apply the primer by brush or roller to the prepared concrete surface and allow to stand for 30 minutes. Reprime any areas that absorb the primer.
If the concrete is very absorbent or blisters form in MASTERTOP 1240 PLUS after it is applied; two coats of primer should be applied as follows:
- Apply the first coat of primer, followed immediately by a light scattering of clean, dry aggregate with a size of minimum 0.3mm to a maximum of 1mm (150grms / m²). DO NOT SATURATE THE WET primer with aggregate.
Allow to dry.
- Reprime the dry lightly sanded surface before continuing with the MASTERTOP 1240 PLUS application as normal. The aggregate applied to the first layer of primer will act as a key to stop the MASTERTOP 1240 PLUS slipping across the wet surface as it is trowelled down.
Do not allow the primer to pond; ensure the primer is applied at a uniform rate.
If pools of primer are allowed to form, they can affect the finish of the MASTERTOP 1240 PLUS by altering the resin to aggregate ratio locally.
If the primer becomes tack free before it can be overlaid, it must be reprimed.
Mixing
Forced action mixers are preferred for mixing MASTERTOP 1240 PLUS.
Suitable mixers are:
- Creteangle
- Pennine
- Mixal or similar
- Slow speed electric drill with spiral mixer
Mixing can start 25-30 minutes after the start of priming, allowing the primer to penetrate the substrate.
Mix components A and B and the colour pack together until it is apparent that the material is uniformly mixed, then slowly add the aggregate. A total mixing time of 4 minutes should be adequate. To ensure consistent colour and surface texture all batches of material should be mixed for the same length of time.
Laying
Always lay MASTERTOP 1240 PLUS between screed battens to achieve a flat surface finish. The thickness of the battens will be determined by the required minimum or average thickness for the screed. Flat steel strip is ideal for screed battens, as the weight helps keep them in position when screeding takes place.
Place the mixed MASTERTOP 1240 PLUS between the screed rails and spread to a rough level with a rake or wooden float then strike off to level with a screed board. Tamp the MASTERTOP 1240 PLUS with a wooden float to aid compaction, and close the surface with a steel float.
Note:
To improve the ease of working, use a steel float 85-90mm wide.
Do not overwork the surface with the steel float as resin can be drawn to the surface, leaving a patchy finish. Regularly clean the face of the trowel with a cloth damped in Cleaning Solvent No. 2 and also remove the resin build up from the edge of the trowel. If the build up of resin is not removed, it will drop off the trowel and be worked into the finished surface causing resin rich patches.
Sealing
If an easy to clean and / or hygienic surface is required, MASTERTOP 1240 PLUS can be overcoated with MASTERTOP 1110 T or MASTERTOP 1120 T.
MASTERTOP 1240 PLUS must be allowed to cure for a minimum of three days at 20°C before overcoating with MASTERTOP 1120 T.
MASTERTOP 1110 T can be applied as soon as the MASTERTOP 1240 PLUS can take pedestrian traffic.
Watch points
Do not:
- Apply MASTERTOP 1240 PLUS when the substrate is less than 10°C or when the ambient temperature will fall below 10°C during application or curing, unless heating equipment is available to raise the ambient temperature.
- Prime areas unless they can be covered before the primer sets.
- Allow primer to form pools.
- Mix more material than the can be laid within the open time of the product.
- Attempt to remix material once it starts to stiffen.
Note
Field service, where provided, does not constitute supervisory responsibility. For additional information contact your local BASF representative.
BASF reserves the right to have the true cause of any difficulty determined by accepted test methods.