Repair Systems — 03 — Facade & External Envelope
Movement joint sealant systems
Technical product reference for movement joint sealant systems used where facade cracking has occurred due to inadequate or absent movement joint provision. Covers systems for creating or reinstating movement joints in rendered facades, including joint formation profiles, elastomeric sealants and joint tape systems — to accommodate ongoing thermal and structural movement and prevent recurring cracking.
What are movement joint sealant systems in facade crack remediation?
Movement joint sealant systems for facade crack remediation address cracking that has occurred because the facade lacks adequate movement joint provision — no control joints, inadequate joint spacing, or failed existing joints. Unlike flexible crack fillers applied directly into a crack, movement joint systems involve deliberately forming a joint at the crack location: the crack is chased (cut or routed) to create a wider, parallel-sided slot of designed dimensions, then a sealant-backed joint system is installed to accommodate the ongoing movement that caused the crack.
Product Reference
3 products — 3 brands — movement joint sealant systems for facade crack remediation — scroll to view all
Sikaflex-11FC+ (movement joint formation)
One-part PU movement joint sealant — formed facade joints — paintable
System Description
Sikaflex-11FC+ applied into a properly formed movement joint is the most commonly specified movement joint sealant system in Australian Class 2 strata facade remediation where facade cracking has occurred due to inadequate or absent movement joint provision. The process involves: (1) chasing out the crack location to form a parallel-sided joint of adequate width (typically 10–20mm) and depth; (2) cleaning the joint faces; (3) applying Sika Primer-3N to joint faces and allowing to flash off; (4) installing a closed-cell PE foam backer rod at the correct depth; (5) applying Sikaflex-11FC+ by gun and tooling flush or slightly concave. The formed joint accommodates ±25% movement — the crack cannot recur because the joint has replaced the rigid crack location with a flexible sealant. After cure, the joint can be overpainted. The joint width must be designed for the expected movement — typical facade movement joints are 10–20mm wide. Confirm joint dimensions and primer from the current Sika system guide.
Technical Properties
- One-part moisture-curing — no mixing — applied from cartridge
- ±25% movement accommodation (ISO 11600 F-25LM)
- Paintable after cure — suitable for overcoating with facade paint
Limitations
- Joint must be properly formed (chased) to correct width and parallel faces — cannot be applied into V-shaped crack without forming
- Primer flash-off must be observed before applying sealant
- Backer rod must be installed before sealant application — no three-sided adhesion
PROCUREMENT SOURCES
Confirm suitability with current manufacturer TDS. Movement joint design requires professional assessment.
Tremco Vulkem 116 (movement joint formation)
One-part PU movement joint sealant — high-movement facade joints
System Description
Tremco Vulkem 116 applied into a properly formed movement joint is a high-movement facade crack remediation system. Where facade cracking has occurred at a location subject to significant ongoing thermal movement, a movement joint wider than a standard control joint may be required to accommodate the movement demand without sealant failure. Tremco Vulkem 116 offers high movement accommodation suitable for these applications. The crack must be chased to form a parallel-sided joint of adequate width, joint faces cleaned, primer (Tremco 636 or equivalent) applied and flashed off, closed-cell backer rod installed, and sealant applied and tooled. The formed movement joint prevents recurring cracking by providing a controlled flexible zone at the expected movement location. Confirm joint dimensions, primer requirements and movement class with Tremco Australia technical. TODO: owner confirm — confirm primer requirements, movement class and current product designation with Tremco Australia.
Technical Properties
- One-part moisture-curing — applied from cartridge
- High movement accommodation — suitable for wider or more active facade joints
- Paintable after cure — confirm with Tremco Australia
Limitations
- Joint must be properly formed — parallel-sided, adequate width, correct depth
- Primer must flash off before sealant application
- Backer rod required — prevents three-sided adhesion failure
PROCUREMENT SOURCES
Confirm suitability with current manufacturer TDS. Movement joint design requires professional assessment.
Ardex FS-40 (facade movement joint)
One-part PU sealant — facade movement joints — Ardex system compatible
System Description
Ardex FS-40 is a one-part polyurethane facade joint sealant from Ardex Australia, used for movement joint sealing in facade remediation and new construction. Where an Ardex render or coating system is being applied as part of the facade remediation scope, Ardex FS-40 provides a compatible sealant for movement joint formation at crack locations within the same manufacturer system. Using products from the same system manufacturer ensures technical compatibility and warranty continuity. Apply into a properly formed joint with Ardex primer (if required — confirm from TDS), closed-cell backer rod and sealant application by gun. Ardex has a national technical and distribution network in Australia. Confirm the current product designation, primer requirement and system compatibility with Ardex Australia technical before specifying. TODO: owner confirm — confirm current product designation, system compatibility, primer requirements and movement class with Ardex Australia.
Technical Properties
- One-part polyurethane — applied from cartridge — no mixing required
- Paintable after cure — compatible with Ardex topcoat systems
- Compatible with Ardex render and coating facade systems
Limitations
- Joint must be properly formed before application — chase crack to parallel-sided joint
- Primer may be required — confirm substrate-specific primer with Ardex Australia
- Backer rod required — confirm closed-cell PE foam before applying sealant
PROCUREMENT SOURCES
Confirm suitability with current manufacturer TDS. Movement joint design requires professional assessment.
System Comparison
Movement joint sealant comparison for facade crack remediation. Always obtain professional assessment before specifying.
| Product | Brand | Movement | Paintable | Primer | System | Primary use |
|---|---|---|---|---|---|---|
| Sikaflex-11FC+ | Sika | ±25% | Yes | Sika Primer-3N on porous | Universal — any facade system | Most common movement joint sealant in Australian Class 2 strata facade crack remediation |
| Vulkem 116 | Tremco | High — confirm TDS | Yes — confirm | Tremco 636 may be required | Tremco sealant system | High-movement facade joints — where ±25% is insufficient — confirm with Tremco technical |
| Ardex FS-40 | Ardex | Confirm TDS | Yes | Confirm Ardex TDS | Ardex render / coating system | Movement joint sealing where Ardex render or coating system is part of the scope |
Do not confuse movement joint systems with:
- Rigid crack repair (epoxy or cementitious crack filler — rigid — will crack again at the same location if movement is ongoing — not suitable where movement is the cause of cracking)
- Flexible crack filler without joint formation (crack fillers applied directly into a crack without forming a proper sealant-depth joint and backer rod — correct joint geometry is required for movement accommodation — listed on the flexible crack filler systems page)
- Structural movement joint (large-scale building expansion joints through the full structure — different engineering requirement — consult structural engineer)
- Grout injection (injection of cementitious or epoxy grout into cracks — rigid — appropriate only for non-movement structural cracks — not for thermally active facade cracks)
Disclaimer
This page provides general technical information only. Facade cracks must be assessed by a qualified building consultant or engineer before specifying any repair system. Movement joint formation requires correct joint geometry and sealant depth — always follow manufacturer TDS and relevant standards.