Preparation
The condition of the surface to be treated is of great importance. The substrate must be mechanically prepared e.g. scabbled, milled or shot blasted. All laitance and contamination must be removed to leave a clean aggregate exposed finish. Testing and assessment to BS8204 Part 7 should be conducted before proceeding with vacuum cleaning, sealing and priming.
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 pin-holing. 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 Smooth Screed whilst primer is tacky; typically between 2-4 hours after application based on material, ambient and substrate condition of 20°C @ 65%RH.
Coverage
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).
Packaging
RonaScreed Self Smooth Primer is supplied in 5 litre and 25 litre units.