Frequently Asked Questions

How does Renderoc Superpatch compare to Renderoc RSXtra — when should each be used?

Both Renderoc Superpatch and Renderoc RSXtra are rapid-setting repair mortars from the Fosroc Renderoc range, but they are optimised for different use cases. Renderoc Superpatch is the general-purpose rapid-set repair mortar for the broadest range of common patch repair applications on site — it provides a good balance of working time (10 to 15 minutes pot life), early strength, and final strength, making it practical for experienced repair crews without extreme time pressure. Renderoc RSXtra is the specialist ultra-rapid product for situations where even Superpatch is not fast enough — specifically where traffic or service must be restored within 1 to 2 hours rather than 2 to 4 hours. RSXtra has a shorter pot life (5 to 10 minutes), higher final compressive strength (60 MPa versus 50 MPa), and faster initial strength gain. For most maintenance and repair work on buildings, floors, and general infrastructure, Renderoc Superpatch is the practical choice. For bridge deck and highway traffic restoration overnight, RSXtra is the right product.

Does Renderoc Superpatch require a bonding primer for small patch repairs on concrete floors?

For small patch repairs (less than 0.1 to 0.2 square metres and less than 20 mm depth) on concrete floors where the substrate is clean, sound, and suitably rough, Renderoc Superpatch can be applied without a separate bonding primer by applying a slurry coat of the repair mortar itself (mixed to a thin consistency) into the prepared void immediately before placing the standard mortar. This self-slurry technique provides a satisfactory bond for small cosmetic and maintenance patch repairs. For larger patches, deeper repairs, structural repairs, or repairs on smooth or contaminated substrates, a proper bonding primer (Nitobond SBR slurry or Nitobond EP for structural applications) should be applied to the prepared surface and allowed to reach the correct tacky condition before the Superpatch mortar is applied over it.

Can Renderoc Superpatch be used for patch repairs on concrete in an occupied building without vacating the area?

Renderoc Superpatch is a low-odour cementitious repair mortar — it does not contain solvents or volatile organic compounds that would require evacuation of an occupied building for health and safety reasons. The product can be mixed and applied in occupied or semi-occupied buildings provided that the mechanical preparation work (chipping, grinding, or scabbling of the concrete) is managed with dust extraction to minimise airborne dust. The rapid-setting characteristic means that the repair mortar sets and hardens quickly, producing no prolonged off-gassing. The repaired area can typically be walked on within 2 to 4 hours, making Renderoc Superpatch particularly suitable for maintenance repairs in facilities that cannot be fully shut down, such as hospitals, hotels, warehouses, and commercial buildings where minimal disruption is essential.