Repair Systems — 02 — Concrete & Structural Defects
Form release agents for concrete repair formwork
Technical product reference for water-based reactive, wax emulsion, and petroleum-based form release agents applied to plywood and steel formwork before placing repair mortar in concrete spalling repair. Covers product type selection, staining risk, suitable formwork materials, and application method.
Form release agents in concrete spalling repair
A form release agent is applied to formwork before placing repair mortar or concrete to prevent the fresh mortar from bonding chemically and mechanically to the formwork face. Without a release agent, removal of formwork from set cementitious repair mortar can damage the mortar surface, spall repair edges, and leave mortar adhered to the form — making formwork reuse difficult. In enclosed environments such as carparks and building interiors, water-based, low-VOC reactive release agents are the correct product — petroleum-based alternatives (diesel fuel, mineral oil) are unsuitable due to high fume levels and staining.
Product Reference
Individual products — one card each — scroll to view all
Sika Australia
Sika Separol WB — Water-Based Form Release Agent
Water-based reactive form release agent — steel and plywood formwork
Sika Separol WB is a water-based reactive form release agent used on steel and plywood formwork in concrete spalling repair reinstatement work. A form release agent is applied to the formwork surface before placing repair mortar or concrete — it creates a thin barrier film that prevents the mortar from chemically bonding to the formwork face, allowing the formwork to be stripped cleanly after the mortar has achieved sufficient strength. Sika Separol WB is a low-VOC water-based product suitable for use in enclosed environments including carparks, building interiors, and residential buildings.
Fosroc / Parchem
Fosroc Form Release Agent
Chemical-reactive form release agent — steel, plywood and coated formwork
Fosroc Form Release Agent is the current Parchem-distributed form release agent for concrete formwork (the older Reebol WB is discontinued in Australia). It is applied as a thin, even film by spray or brush to steel, plywood and coated formwork faces before placement, giving a clean strip from the set concrete/mortar with low staining of the formed face. Confirm the current coverage rate, application method and pack size against the current Fosroc / Parchem TDS before specifying.
System Comparison
Concrete spalling — confirm all selections against the current manufacturer TDS before specifying.
Scroll the table sideways to see every column →
Do not confuse form release agents with:
- Bonding agents and SBR latex primers — bonding agents are applied to the concrete substrate (the existing concrete being repaired) to promote adhesion of repair mortar — form release agents are applied to the formwork face to prevent adhesion — applying release agent to the concrete substrate would eliminate mortar bond
- Penetrating concrete sealers (silane, siloxane) — applied to hardened concrete for long-term waterproofing and chloride protection — not the same as formwork release agents and not compatible with fresh mortar
- Epoxy coatings for formwork panels — some proprietary steel formwork systems use epoxy-coated panels that inherently provide some release without a separate release agent — confirm with the form panel supplier whether a separate release agent is required
- Concrete curing agents — curing compounds are applied to the fresh mortar surface after the formwork is stripped, not to the formwork itself — do not confuse the application sequence
- Diesel fuel as a general lubricant — diesel fuel applied to site equipment as a lubricant (not a release agent) is a separate use — diesel used as a form release agent is a practice that should be avoided in enclosed environments and on plywood forms due to staining and environmental risk
Disclaimer
This page provides general technical information only. Final product selection must be confirmed against the current manufacturer technical data sheet, project specification, substrate condition, exposure classification, AS 3600 requirements, and applicator warranty conditions. Do not rely on this reference as a substitute for professional engineering or remedial building consultant advice.