Flexcrete Monolevel 844SP is a single component, polymer modified, fibre reinforced, cementitious repair mortar with high adhesive properties for use as a filler with a fair-faced finish or as a waterproof screed. It provides excellent protection from acid gases, chlorides and freeze/thaw cycles, as well as enhanced chemical resistance.

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• Features & Benefits
• Preparation
• Mixing
• Application & Curing
• Application Top Tips
• Technical Data

Features & Benefits

• Can be applied using bag-rubbing techniques to a feather edge
• May be used typically to 6mm as a waterproof render
• Dense matrix provides high diffusion resistance to moisture, acid gases and chloride ions
• Economic mortar, no substrate or inter-layer priming
• UKCA & CE marked in accordance with EN 1504-3
• Listed under Regulation 31 – England: Regulation 33 – Scotland: Regulation 30 – NI: for use with potable water. WRAS Approved for use with potable water
• Highways Standard Series 5700 (Concrete Repairs) and CS 462 (Repair & Management of Deteriorated Concrete Structures)
• Compliant with LU Standard 1-085 ‘Fire Safety Performance of Materials’

Preparation

Mechanically remove all damaged concrete or failed repairs back to a sound core.

The areas to be repaired must be free from all unsound material including laitance dust, oil, grease, corrosion byproducts and organic growth.

Smooth surfaces should be roughened and reinforcement cleaned to bright steel using wet grit blasting techniques or equivalent approved methods. Power tools such as a needle gun, angle grinder or wire brush may be used on concrete which is not chloride contaminated.

• The compressive strength of the parent concrete should be minimum 20 MPa

The prepared substrate should be thoroughly soaked with clean water until uniformly saturated without any standing water.

Treatment of Steel Reinforcement:

Treat exposed steel reinforcement with 2 x 1mm coats of Steel Reinforcement Protector 841 applied by brush.

• Note - When carrying out repairs in new construction, it is not necessary to fully expose any reinforcing bars.

Priming of Concrete:

Monolevel 844SP does not generally require a primer. Highly porous substrates may be primed with a polymer admixtureslurry coat. The slurry coat should also be used when treating larger areas of waterproof concrete.

Mixing

Monolevel should be mechanically mixed with a forced action pan mixer or in a clean drum using a slow speed drill and paddle. A normal concrete mixer is not suitable.

For normal applications, use between 2.8-3.2 litres of clean water per 25kg bag. For part bags, this equates to 6.5 volumes of powder to 1 volume of water. Typically, for screeding applications use 3 litres of clean water per bag and mix for 2-3 minutes. Mix to entrain as little air as possible. Use without delay.

• Note - These instructions must be adhered to as the manufacturer will not be responsible for failure due to incorrect mixing

Application & Curing

Monolevel can be applied by palette knife to fill minor voids and surface defects. Over larger areas, work well into the prepared substrate using a wooden float, sponge or ‘bag-rubbing’ techniques.

When used as an alkaline thin screed for the protection of concrete and for structural waterproofing, Monolevel should be applied to the prepared substrate using a steel float to provide a smooth polymer rich surface finish. Work an initial thin layer into the surface to fill blow holes and minor defects prior to building up to a typical thickness of 3-6mm. Spray techniques may also be used.

For repairs which require multi-layer applications, it is important to ensure that previous layers have been finished with a wood or plastic float and are stable, but not fully set (typically 2-6 hours) prior to the application of subsequent layers. No inter-layer priming is required. Once the last layer has stabilised, remove trowel marks using a wooden float or damp sponge. This will produce a surface similar in texture to emery paper, which is ideal for the application of a surface coating.

When curing, normal concreting procedures must be adhered to. Protect from strong sunlight and drying winds with polythene sheeting, damp hessian or similar.

Do not use Monolevel 844SP when the temperature is below 5°C and falling. Do not use on waterproof concrete without first referring to our technical department at 0113 2455450. Not suitable for use on trafficked areas.

Application Top Tips

• During early mixing, the material appears dry. Do not add extra water at this stage as full mixing produces a smooth consistency
• Do not wet out or prime between layers
• If the mortar thickens, remix but do not add extra water
• Do not over trowel when applied as a fairing coat otherwise blisters could form in the material, which must be removed
• Remove trowel marks using a wooden float or damp sponge once the surface has stabilised
• Can be overcoated with Flexcrete membranes to give a coloured, aesthetic finish
• Cold Weather Working - ≥3°C on a rising thermometer, ≥5°C on a falling thermometer
• Hot Weather Working - Store material in cool conditions to maximise working life. Shade applied material from strong sunlight. If possible, avoid extreme temperatures by working at night

Technical Data