Sikaflex® AT Facade is designed for joint sealing of movement and connection joints, porous and nonporous substrates such as concrete, brick, steel metals. (TDS p.1)
- Temperature stated in TDS
- 40 °C to +90 °C (TDS p.2)
Step-by-step solution
Facade joints (concrete, block, precast and cladding)
Movement and connection joints on outside walls: between precast panels, at floor slabs, around infill panels and in metal or stone cladding. A sound joint keeps monsoon rain out and lets the facade move.
- 7 steps
- 7 products
- 4 answers
You need this when…
- Rain marks or damp inside along a facade joint
- Sealant cracked, split or pulled away from one side
- Gaps opening between precast panels
- Stained stone beside old sealant joints
The work, step by step
General guidance based on the manufacturer data sheets. Site conditions differ: confirm the system with MCT before you start. Where we do not name a product, ask us and we will confirm the right one.
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Step 1: Survey and size the joints
Sikaflex AT Facade takes joints 10–50 mm wide at a 2:1 width-to-depth ratio. For example, joints at 6 m spacing need at least 20 mm width and 10 mm depth (Sikaflex AT Facade p.2). Joints must be designed to the relevant standards (Sikaflex AT Facade p.2).
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Step 2: Remove old sealant and prepare
The substrate must be sound, clean and dry, free of old sealant, laitance and poorly bonded paint (Sikaflex AT Connection p.3). On multi-storey buildings and highly stressed joints, pre-treat metals, PVC and glazed tiles with Sika Aktivator-205, and prime porous substrates (Sikaflex AT Facade p.3).
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Step 3: Insert the backer rod
Use only closed-cell polyethylene foam backing rods (Sikaflex AT Facade p.2).
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Step 4: Concrete, block, render and precast facades
Sikaflex AT Facade is a low-modulus sealant with ±25 % movement, low stress on the substrate, and can be over-painted (Sikaflex AT Facade p.1). Sikaflex Construction AP covers movement and connection joints on porous substrates (Sikaflex Construction AP p.1). Sikaflex AT Connection covers facade elements, precast, infill panels, cladding and curtain walling (Sikaflex AT Connection p.1).
Sikaflex AT Facade Sika Request a quotation Sikaflex Construction AP Sika Request a quotation Sikaflex® Construction AP is designed for movement and connection joints on porous substrates as well as indoor and outdoor general sealing applications. (TDS p.1)
- Temperature stated in TDS
- −40 °C to +70 °C (TDS p.2)
Sikaflex AT Connection Sika Request a quotation Sealing joints for: Movement and connection joints, Facade elements, Balconies, Window and door frames, Pre-cast elements, Infill panels. (TDS p.1)
- Temperature stated in TDS
- −40 °C to +70 °C (TDS p.2)
- Pack
- 300 ml cartridges
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Step 5: Natural stone, GRC and metal cladding
Sikasil-715 WS lists curtain wall and metal cladding facades, GRC and precast, and natural stone joints after checking with Sika. Its movement capability is ±50 % (Sikasil-715 WS p.1). Prime porous substrates with Sika Primer-3 N or Primer-210 (Sikasil-715 WS p.3). SikaHyflex-305 EU is a weather sealant for curtain walls and metal cladding (SikaHyflex-305 EU p.1). Do not use it on natural stone (SikaHyflex-305 EU p.3).
Sikasil-715 WS Sika Sikasil®-715 WS is designed for weather proofing and sealing applications where durability under severe conditions is required. (TDS p.1)
- Temperature stated in TDS
- +5 °C to +40 °C (TDS p.2)
- Pack
- 300 ml cartridge, 12 cartridges per box
SikaHyflex-305 EU Sika SikaHyflex®-305 EU is designed for weather proofing and sealing applications where durability under severe conditions is required. (TDS p.1)
- Temperature stated in TDS
- +5 °C to +40 °C (TDS p.2)
- Pack
- 300 ml catridge, 25 cartridges per box
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Step 6: Building separation joints on high-rise facades
Sika Polysulphide GG lists vertical expansion joints in high- and low-rise buildings, with ±25 % movement at 2:1 (Sika Polysulphide GG p.1, p.2). Prime with Sika Primer PS (Sika Polysulphide GG p.3).
Sika Polysulphide GG Sika It is used in both vertical and horizontal expansion joints in many types of buildings and civil engineering constructions such as: Retaining walls, Underpasses and tunnels, Reservoirs, Precast concrete elements, Bridges, High and low rise buildings and. (TDS p.1)
- Temperature stated in TDS
- -20 °C min. / +80 °C max (TDS p.2)
Sika Primer PS Sika It is used on porous substrates such as concrete, brick work and timber. (TDS p.1)
- Temperature stated in TDS
- +5 °C min. / +40 °C max (TDS p.1)
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Step 7: Tool, then paint if needed
Tool the sealant firmly against the joint sides, and do not use solvent tooling products (Sikaflex Construction AP p.3). Sikaflex AT Facade can be painted after a compatibility trial (Sikaflex AT Facade p.3). Silicones such as Sikasil-715 WS cannot be over-painted (Sikasil-715 WS p.3).
Proposal brief
Facade joints (concrete, block, precast and cladding): scope and system
A starting point for a site proposal. Quantities, prices and the final specification follow a site visit or photos.
Scope of work
- Survey of x running metres of facade joints
- Cutting out old sealant and preparing joint faces
- Backer rod, priming and sealing
- Optional over-painting to match the facade
System build-up
| Step | Product | Pack | Source |
|---|---|---|---|
| 4. Concrete, block, render and precast facades | Sikaflex AT Facade | — | TDS p.1 · May 2021, Version 02.01 |
| 4. Concrete, block, render and precast facades | Sikaflex Construction AP | — | TDS p.1 · May 2021, Version 01.01 |
| 4. Concrete, block, render and precast facades | Sikaflex AT Connection | 300 ml cartridges | TDS p.1 · May 2021, Version 03.01 |
| 5. Natural stone, GRC and metal cladding | Sikasil-715 WS | 300 ml cartridge, 12 cartridges per box | TDS p.1 · May 2025, Version 03.01 |
| 5. Natural stone, GRC and metal cladding | SikaHyflex-305 EU | 300 ml catridge, 25 cartridges per box | TDS p.1 · December 2022, Version 03.01 |
| 6. Building separation joints on high-rise facades | Sika Polysulphide GG | — | TDS p.1 · May 2021, Version 02.01 |
| 6. Building separation joints on high-rise facades | Sika Primer PS | — | TDS p.1 · March 2026, Version 01.01 |
What we need from you
- Facade materials (concrete, block, precast, stone, metal, GRC)
- Joint length (running metres) and typical width
- Building height and access (scaffold, rope access, lift)
- Photos of leaking or failed joints
Site conditions
- Dry joint faces and dry weather during sealing (Sikaflex AT Connection p.3)
- Substrate +5 °C to +40 °C (Sikaflex AT Facade p.2)
Not included
- Access equipment (scaffold, rope access) unless agreed
- Repair of cracked panels or cladding fixings, which needs an engineer's check
- Facade painting beyond the joint lines
Questions customers ask
Can the sealant be painted to match the wall?
Sikaflex AT Facade can be over-painted after a compatibility trial (Sikaflex AT Facade p.1, p.3). Silicone such as Sikasil-715 WS cannot be over-painted (Sikasil-715 WS p.3).
Which sealant next to marble or granite cladding?
Not Sikaflex AT Facade or Construction AP (Sikaflex AT Facade p.3; Sikaflex Construction AP p.3). Sikasil-715 WS lists natural stone joints, after checking with Sika (Sikasil-715 WS p.1).
Why did the old joint split down the middle?
Ask us: it depends on site conditions. Common checks are joint width against movement, and the 2:1 width-to-depth ratio (Sikaflex AT Facade p.2).
How much movement can these sealants take?
Sikaflex AT Facade ±25 % (Sikaflex AT Facade p.1). Sikasil-715 WS ±50 % (Sikasil-715 WS p.1).
Steps and product facts are taken from the manufacturer data sheets (page cited). Products are named only where the data sheet confirms the use; quantities follow a site visit or photos. General guidance: check the data sheet or ask us before you start.