Fosroc Renderoc HB25

Product Overview

Renderoc HB25 is a ready-to-use blend of dry powders based on Portland cements, graded aggregates, lightweight fillers and chemical additives. It requires only the site addition of clean water to produce a highly consistent, lightweight repair mortar. Specifically designed for vertical and overhead repair work, it can be applied in thick sections without formwork. Its alkaline nature helps protect embedded steel reinforcement.

Key Features

• Lightweight high-build formulation — saves time and cost of multiple applications
• No formwork required — up to 80mm vertical, 60mm overhead in a single pass
• Polymer-modified — extremely low permeability to water, carbonation and chlorides
• Excellent bond — superior adhesion to concrete substrate
• Shrinkage compensation system — reduces cracking risk
• Single-component premix — just add water, pre-bagged to overcome site-batched variations
• Chloride-free — will not accelerate reinforcement corrosion
• Fast strength gain, suitable for time-critical projects

Applications

• Large and small area concrete patch repairs
• Vertical spalling repairs (up to 80mm without formwork)
• Overhead / soffit repairs (up to 60mm without formwork)
• Structural reinforced concrete member repairs
• Applications requiring a lightweight repair mortar

Standards Compliance

• Tested to HKHA Specification TM1–TM8 (1990) (per manufacturer)
• BBA approved (per manufacturer)
• Complies with PCCS-RM (2010) (per manufacturer)

Application Notes

• Surface preparation — remove all loose concrete, dust, oil and corrosion deposits
• Steel priming — apply Nitoprime Zincrich (WB) to exposed reinforcement
• Substrate priming — apply Nitobond SBR / cement slurry bond coat
• Mixing — add water per manufacturer instructions, mix with a forced-action mixer until homogeneous
• Application — up to 80mm vertical, 60mm overhead per coat
• Finishing — steel, plastic or wood float, or damp sponge technique

Packaging

18 kg bag

FAQ

HB25 or HB40 — which one to choose?

HB25 is Class 25 (general repairs), lightweight formula for thick application (up to 80mm vertical). HB40 is Class 40 (structural repairs) with higher strength. The engineering specification will state the required grade.

What is "25 material" (25料)?

"25 material" is the Hong Kong construction industry's colloquial term for Class 25 repair mortar. Renderoc HB25 is certified to HKHA TM1–TM8 specifications.

What primers are needed before application?

Exposed reinforcement requires Nitoprime Zincrich (WB) anti-corrosion primer. The concrete substrate requires a Nitobond SBR / cement slurry bond coat. Refer to the official product data sheet for full details.