From product selection to application advice, the Fosroc ANZ team is here to help your project succeed. Here's one of the frequently asked questions we receive from trade professionals. 

Q: I only need half a bag of Renderoc mortar, can I split the bag and just mix what I need? 

A: Yes, but mixing the full 20 kg bag is our recommended strategy to ensure the correct ratios are used and the consistency is just right for product performance. 

For applications where smaller quantities of product are required, experienced applicators may elect to mix half bags by weighing out 10 kg of powder and mixing with half the recommended quantity of water. In doing so, the contractor accepts the risk of any off-ratio mixing.  

Remember, accuracy is essential! Here's our recommended four-step process for experienced applicators to mix smaller quantities of Renderoc mortar: 

  1. Calculate the required quantity of mortar and water, ensuring the correct ratio is used. Refer to the "water to mortar ratio" printed on the product packaging.  

  1. Agitate the dry product before weighing out to minimise any segregation.   

  1. Weigh out individual components. Reliable scales are a must! 

  1. Mix as detailed on the product packaging or in the product TDS. 

Choosing a concrete repair solution 

Fosroc has concrete repair mortars for diverse applications, including Renderoc, Guncrete, Patchroc and Paveroc products. 

In the HB25, HB40, HB70 and LA55 ranges, Renderoc’s high build and extra high build repair mortars offer shrinkage compensation to ensure long term dimensional stability, as well as low permeability to resist water, carbon dioxide and chlorides. Most of these products comply to the standard requirements of EN1504-3.  

The LA55 products are free flowing micro-concretes, including the Renderoc LA55 Rapid product for when fast setting is required. 

Fosroc also offers mortars for specialised applications: 

  • For small repairs, Renderoc HB is the ‘original’ Renderoc, a general purpose, high build repair mortar. 

  • Renderoc FC is a fairing coat to cover surface imperfections. 

  • Conforming to EN1504-3 Class R3, Renderoc ST 06 is a two-part protective cementitious mortar for surface repairs, ideal for where low concrete cover needs to be rectified. 

  • Acid-resistant Renderoc G is used for highly corrosive environments. 

  • To resist biogenic corrosion, Renderoc CAC is a blend of calcium aluminate cement and aggregates. 

  • Trafficable within two hours, Renderoc Rapid is for fast setting repairs to horizontal surfaces. 

  • Guncrete E is a low rebound dry-spray applied repair mortar. 

  • Patchroc GP and Patchroc C are fast setting patch repair mortars for floors and pavements, while Paveroc can repair larger floor and pavement areas.   

For more information about the Renderoc range, including a product selection guide, download our Concrete Repair Solutions brochure here.

You can request a specification here or scroll to the bottom of this page to get in touch with our team for application support.