SikaHyflex®-355
SikaHyflex®-355 is a silicone based, 1-component, moisture curing, low-modulus elastic weather sealant. Suitable for use in hot and tropical climatic conditons.
- Very good weathering resistance
- Non-staining and non-streaking
- Movement capability of ± 35 % (ASTM C 719)
- Very good workability
- Low stress to the substrate
- Solvent-free
- Very low emissions
Usage
SikaHyflex®-355 is designed for weather proofing and sealing applications where non-staining and non-streaking properties are required. SikaHyflex®-355 is particularly suited for use as a weather sealant for natural stone and metal cladding facades. It is also suitable for movement and connection joints in floors and pedestrian areas, where natural stone is used.Advantages
- Very good weathering resistance
- Non-staining and non-streaking
- Movement capability of ± 35 % (ASTM C 719)
- Very good workability
- Low stress to the substrate
- Solvent-free
- Very low emissions
Packaging
600 mL foil pack, 20 foil packs per box
Colour
Black, grey S4, grey S6, beige and bronze
Product Details
SUSTAINABILITY
SikaHyflex®-355 conforms to LEED® EQc 4.1
- VOC content < 50 g/l (US EPA Method 24)
- LEED® EQc 4.1
- SCAQMD, Rule 1168
- BAAQMD, Reg. 8, Rule 51
APPROVALS / CERTIFICATES
- ASTM C920 class 35
- EN 15651-1 F EXT-INT CC 25 LM
- EN 15651-2 G CC 25 LM
- ISO 11600 F 25 LM & G 25 LM
- ISO 16938-1
- ASTM C1248
Composition
Neutral cure silicone
Shelf life
SikaHyflex®-355 has a shelf life of 12 months from the date of production, if it is stored in undamaged, original, sealed packaging, and if the storage conditions are met.
Storage conditions
SikaHyflex®-355 shall be stored in dry conditions, where it is protected from direct sunlight and at temperatures between +5 °C and +25 °C.
Density
~1.45 kg/l | (ISO 1183-1) |
Compatibility
SikaHyflex®-355 is compatible with most SikaHyflex® and Sikasil® silicone weather sealants. All other sealants and adhesives have to be approved by Sika before using them in direct contact with SikaHyflex®-355.
Where two or more different reactive sealants and/or adhesives are used, allow the first one to cure completely before applying the next one. For specific information regarding compatibility contact our Technical Department.
Shore A Hardness
~25 (after 28 days) | (ISO 868) |
Secant Tensile Modulus
~0.40 N/mm2 at 100 % elongation (23 °C) | (ISO 8339) |
| ~0.50 N/mm2 at 100 % elongation (−20 °C) |
Elastic Recovery
~85 % | (ISO 7389) |
Tear Propagation Resistance
~4.0 N/mm | (ISO 34) |
Movement Capability
| ± 35 % | (ASTM C 719) |
Resistance to Weathering
10 | (ISO / DIS 19862) |
Service Temperature
-40 °C min. / +150 °C max.
Joint Design
The joint width must be designed to suit the joint movement required and the movement capability of the sealant. The joint width shall be ≥ 6 mm and ≤ 45 mm. The joint depth shall be ≥ 6 mm and ≤ 15 mm. A width to depth ratio of 2 : 1 must be maintained (for exceptions, see table below).
Typical joint dimensions
| Joint Width [mm] | Joint Depth [mm] |
| 6 | 6 |
| 10 | 6 |
| 15 | 8 |
| 20 | 10 |
| 25 | 12 |
| 30 | 15 |
| 45 | 15 |
All joints must be correctly designed and dimensioned in accordance with the relevant standards, before their construction. The basis for calculation of the necessary joint widths are the type of structure and its dimensions, the technical values of the adjacent building materials and the joint sealing material, as well as the specific exposure of the building and the joints.
For larger joints please contact our Technical Department.
Application
Backing Material
Use closed cell, polyethylene foam backing rods.
Sag Flow
~2 mm (20 mm profile at 50 °C) | (ISO 7390) |
Ambient Air Temperature
+5 °C min. / +40 °C max. (min. 3 °C above dew point temperature)
Substrate Temperature
+5 °C min. / +40 °C max.
Curing Rate
~2 mm/24 h (23 °C / 50% r.h.) | (CQP 049-2) |
Skinning time
~20 min. (23 °C / 50% r.h.) | (CQP 019-1) |
Consumption
| Joint length [m] per 600 mL foil pack | Joint width [mm] | Joint depth [mm] |
| 16.7 | 6 | 6 |
| 10 | 10 | 6 |
| 5 | 15 | 8 |
| 3 | 20 | 10 |
| 2 | 25 | 12 |
| 1.3 | 30 | 15 |
| 1 | 40 | 15 |
| 0.9 | 45 | 15 |
SUBSTRATE PREPARATION
The substrate must be clean, dry, sound and homogeneous, free from oils, grease, dust and loose or friable particles. The following priming and/or pre-treatment procedures shall be followed:
Non-porous substratesFloat glass, coated glass, anodised aluminium and stainless steel have to be pre-treated using Sika® Aktivator-205, Sika® Aktivator-100 or Sika® Cleaner P. Powder coated and PVDF coated metals have to be pre-treated using Sika® Aktivator-205. For details like application and flash-off times refer to the most recent Product Data Sheet of the respective pre-treatment product.
Porous substratesConcrete, aerated concrete and cement based renders, mortars and bricks shall be primed using Sika® Primer-3 N or Sika® Primer-210. For details like application and flash-off times refer to the most recent Product Data Sheet of the respective pre-treatment product.
Adhesion tests on project specific substrates must be preformed prior to application. For more detailed advice and instructions please contact our Technical Department.
Note: Primers are adhesion promoters. They are neither a substitute for the correct cleaning of a surface, nor do they improve the strength of the surface significantly.
CLEANING OF EQUIPMENT
Clean all tools and application equipment immediately after use with Sika® Remover-208 and/or Sika® TopClean T. Once cured, residual material can only be removed mechanically.