RonaScreed Self Smoothing Levelling Base is a flow applied underlay screed for commercial and industrial floors. It provides a hard, durable base for RonaScreed Self Smooth Topping or floor finishes such as sheet vinyl, carpet or tiles. The material gains strength quickly and can be accessed by foot traffic in 24 hours.

Quick Links - Click To Jump To Section:

   
• Features & Benefits
• Achievable Surface Finish
• Preparation
• Priming with RonaFloor Epoxy DPM
• Priming and Sealing with RonaScreed Self Smooth Primer
• Notes
• Mixing/Laying
• Estimating Guide
• Application Temperature
• Joints
• Cleaning

Features & Benefits

• Conforms to BS EN 13813
• Self-smoothing cementitious underlayment screed
• Base layer for RonaScreed Self Smooth Topping or floorings such as vinyl or tiles
• Up to 1500m2 can be pumped per day
• Moisture tolerant - suitable for wet areas and external use
• Early return to light foot traffic—24 hours @ 20°C
• Can be pumped or poured
• Application from 10mm

Achievable Surface Finish

Due to the nature of the product the risk of air bubbles, pinholes and surface undulations cannot be entirely eliminated. Correct substrate preparation, effective sealing and priming and correct mixing/ application will provide optimum results. It is recommended that a Ronacrete Approved Contractor should be employed.

The presence of surface imperfections will not impair the performance of the product.

Preparation

The concrete must be mechanically prepared by vacuum shot blasting or scabbling to fully remove laitance and then cleaned to remove contamination, Loose shot and dust should be removed by vacuum cleaning before the process of sealing and priming commences. Pins may be placed in the floor to set out the required levels.

Priming with RonaFloor Epoxy DPM

Priming of the substrate with RonaFloor Epoxy DPM is the preferred priming method. A single coat of RonaFloor Epoxy DPM is usually sufficient to seal the substrate and provide good adhesion. RonaFloor Epoxy DPM should be applied at the rate of 3.3m²/kg and kiln dried sand (grade 8/16 approximately 0.8-1.4mm applied at the rate of 2.5kg/m²) should be scattered into the wet resin.

Loose aggregate must be removed by vacuum cleaning before application of RonaScreed Self Smoothing Levelling Base. RonaFloor Epoxy DPM should be allowed to cure for 18-24 hours @ 20°C before loose aggregate is removed.

Priming and Sealing with RonaScreed Self Smooth Primer

Substrate Sealing

Seal the prepared surface by applying one or more coats of RonaScreed Self Smooth Primer diluted with 5 parts water at the rate of 0.62 litres/m². Allow to dry for not more than 36 hours; protect the surface and keep clean.

Note that inadequate sealing will increase the risk of pinholing. Very porous substrates may require the application of two or more coats of sealer. Whilst it is difficult to determine whether a substrate has been sufficiently sealed, a sheen on the surface of the substrate is an indication of adequate sealing.

Substrate Priming

Prime the sealed surface by applying one coat of RonaScreed Self Smooth Primer diluted with 3 parts water at the rate of 0.71 litres/m². Brush this well into the surface. Apply RonaScreed Self Smoothing Levelling Base whilst primer is tacky; typically between 2-4 hours after application based on material, ambient and substrate condition of 20°C @ 65%RH.

Notes

• Remove any ponded primer
• The primer must not be allowed to dry out before applying RonaScreed Self Smoothing Levelling Base
• Always prime the surface within 36 hours of sealing
• Always apply RonaScreed Self Smoothing Levelling Base to tacky primer
• When RonaScreed Self Smooth Topping is to be applied to RonaScreed Self Smoothing Levelling Base, apply RonaScreed Self Smooth Primer only

Mixing/Laying

RonaScreed Self Smoothing Levelling Base may be applied either by mixer/pump Putzmeister SP 11 THF (or similar, note that continuous feed pumps may not provide adequate dispersal of components) or when mixing smaller quantities, mix with a slow speed drill ≤ 450RPM fitted with an MR3 type helical paddle and pour onto the floor.

Pump or pour RonaScreed Self Smoothing Levelling Base onto the prepared and sealed/primed surface and level with a pin rake. Spike rolling is necessary to expel entrapped air and must be completed before the mix begins to gel, to avoid leaving spike marks in the surface.

For pump applications it is recommended that a contractor with the necessary experience to carry out this type of work is employed.

Estimating Guide

• 5mm screed: 8.5kg/m²
• 10mm screed: 17.0kg/m²
• 15mm screed: 25.5kg/m²
• 20mm screed: 34.0kg/m²

Priming with RonaFloor Epoxy DPM

RonaFloor Epoxy DPM @ 3.3m2/kg: 0.8-1.4mm kiln-dried sharp sand @ 2.5kg / m²

Sealing and Priming with RonaScreed Self Smooth Primer

Divide surface area by 3.5 to calculate quantity of litres of RonaScreed Self Smooth Primer needed for sealing and priming e.g. 1000m² divided by 3.5 = 286 litres of Primer needed which is enough for one coat of sealer and one coat of primer).

Application Temperature

The substrate and ambient temperature must not be less than 5°C on a rising thermometer at time of application. Materials should be at a temperature of 15°C-20°C at time of application; lower temperatures will impair flow and surface finish. There should be light ventilation during and after laying.

Apply the material within 15 minutes of mixing (at 20°C). Protect the fresh screed from direct sunlight during the hydration/drying process. Low temperatures will reduce the flow of the wet screed and increase the risk of surface undulations and imperfections. Take extra care when working at low temperatures.

Joints

It is recommended that isolation joints are positioned in doorways. Large areas should be sub-divided by using temporary dividing strips to limit bay width, ensuring that a wet edge is maintained. Bay joints and movement joints in the substrate must be brought through into the topping.

Cleaning

Tools and equipment should be cleaned with water immediately after use. Cured material can be removed mechanically or by acid etching.