Repair Systems
Bonding agents & SBR latex
SBR polymer bonding agent and primer — technical reference for concrete spalling in Australian remedial building practice. Covers system selection, product comparisons, and brand equivalents.
What is bonding agents & sbr latex?
SBR bonding agents and latex admixtures are water-based polymer emulsions used to improve adhesion between new repair materials and existing concrete or masonry substrates. Applied by brush or roller to the prepared substrate immediately before the repair mortar is placed — the mortar must go on before the bond coat skins over, which is a critical timing requirement. SBR latex also functions as a mortar admixture, added directly to the mix at approximately 10% of the water weight to improve flexibility, reduce shrinkage, and enhance workability. Without a bond coat in most repair mortar systems, premature delamination is the predictable result. Specified as part of a complete repair system by engineers in accordance with EN 1504-4 adhesion bonding requirements.
Product Reference
Scroll right to see all brands. Use each card's TDS link for verified specifications before specifying on any project.
Sika Latex SBR
SBR latex bonding admixture, 5 L; Sika Icosit EP Primer – epoxy bond coat, 5 L kit
System Description
Brush onto prepared substrate before mortar. Also added to mortar mix at 10% by weight of water.
Technical Properties
- Part of the Sika MonoTop repair system — specified alongside Sika repair mortars in Sika system documentation
- Dual use: brush-on bond coat to prepared substrate, or added to cementitious mortar at ~10% of mixing water by weight
- Improves flexibility, tensile adhesion, and carbonation resistance of cementitious repair mortars
- Available in 5 L and 20 L drums from Sika distributors
Limitations
- Timing is critical — mortar must be placed before the SBR bond coat skins over, typically within 30 min at 20°C
- Does not qualify as an epoxy bond coat — where EN 1504-4 or engineer specification requires epoxy primer, use Sika Icosit EP Primer
- Not suitable as a standalone waterproofing treatment
PROCUREMENT SOURCES
System Description
Brush onto prepared substrate before mortar. Also added to mortar mix at 10% by weight of water.
Technical Properties
- Dual function: apply undiluted as a substrate bonding primer, or add to cementitious mortar mix as an SBR admixture
- Improves mortar flexibility, reduces shrinkage, and increases bond pull-off strength on existing concrete
- Specified component in the Ardex repair system — part of Ardex warranted application
- Water-based — easy clean-up, low VOC, suitable for enclosed spaces
Limitations
- Must be applied wet-on-wet as bond coat — if it dries before mortar placement it becomes a bond breaker
- Not a waterproofing coating — SBR improves bond strength only; it is not a substitute for membrane waterproofing
- Admixture dilution ratio must strictly follow the Ardex data sheet — do not over-dose
PROCUREMENT SOURCES
Fosroc Nitobond SBR
SBR latex bonding agent, 5 L; Fosroc Nitobond EP – epoxy bond coat, 5 L
System Description
Brush onto prepared substrate before mortar. Also added to mortar mix at 10% by weight of water.
Technical Properties
- Standard bond coat for all Fosroc repair mortars — specified component in the complete Fosroc repair system
- SBR emulsion provides mechanical and chemical key for repair mortar on prepared concrete
- Adds flexibility to mortar mix when used as an admixture — reduces early shrinkage cracking
- Compatible with Nitobond EP for dual-coat priming on chloride-affected substrates
Limitations
- Wet-on-wet application required — if allowed to dry before mortar placement, bond improvement is lost and delamination risk increases
- Not an epoxy primer — for chloride-affected structural repairs, engineer may require Nitobond EP epoxy primer in addition
- Shelf life limited once opened — use within manufacturer-specified period
PROCUREMENT SOURCES
System Description
Brush onto prepared substrate before mortar. Also added to mortar mix at 10% by weight of water.
Technical Properties
- Standard bond coat for all Fosroc repair mortars — specified component in the complete Fosroc repair system
- SBR emulsion provides mechanical and chemical key for repair mortar on prepared concrete
- Adds flexibility to mortar mix when used as an admixture — reduces early shrinkage cracking
- Compatible with Nitobond EP for dual-coat priming on chloride-affected substrates
Limitations
- Wet-on-wet application required — if allowed to dry before mortar placement, bond improvement is lost and delamination risk increases
- Not an epoxy primer — for chloride-affected structural repairs, engineer may require Nitobond EP epoxy primer in addition
- Shelf life limited once opened — use within manufacturer-specified period
PROCUREMENT SOURCES
System Description
Brush onto prepared substrate before mortar. Also added to mortar mix at 10% by weight of water.
Technical Properties
- Acrylic polymer bonding primer from the Tremco CPG repair system
- Applied to prepared concrete substrate before Tremco repair mortar placement
- Water-based acrylic — low VOC, quick dry for site efficiency
Limitations
- Verify current product name and formulation with Tremco CPG Australia before specifying
- Acrylic type only — confirm compatibility with specific mortar; epoxy primer may be required in some engineer specifications
- Tremco distribution is more limited than Sika/Fosroc/Ardex — confirm local availability
PROCUREMENT SOURCES
Brand Equivalents
Side-by-side view of equivalent products across all major brands.
| Material | Ardex | Sika | Fosroc | Tremco / Other | Parchem / Mapei |
|---|---|---|---|---|---|
| Bonding agent / SBR latex | Ardex P 51 | Sika Latex SBR | Fosroc Nitobond SBR | Tremco THC Bonding Agent | Fosroc Nitobond SBR |
Disclaimer
Information is general only. Product selection must be confirmed against project requirements, substrate condition, exposure class, manufacturer technical data sheets, NCC requirements, Australian Standards (including AS 3600), and consultant or structural engineer specifications. Do not rely on this reference as a substitute for professional engineering advice.
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