Sikaflex® MS
High performance multi-purpose SMP sealant
Sikaflex® MS is a tough, durable elastomeric joint sealant suitable for use in a wide range of external and internal building applications. It is based upon SMP technology resulting in a unique combination of properties ideally suited to New Zealand climatic conditions. Sikaflex® MS has excellent primerless adhesion to a wide range of common building substrates as indicated below and does not stain concrete, marble and other masonry surfaces.
- Good primerless* adhesion to most common building materials
- Paintable any time after curing, with water-based paints (compatibility testing recommended prior to full application)
- Will not stain masonry, marble or other surfaces
- Very durable - BRANZ appraised
- Neutral cure
- Highly flexible
- Low odour

Usage
Sikaflex® MS has been formulated for sealing joints in and around concrete, brick, masonry, pre-cast panels, stone cladding, windows, doors and fibre cement sheeting. Suitable for use as an Airseal. Sikaflex® MS bonds well to:- Concrete and masonry
- Cement plaster systems
- Aluminium, copper, brass and zinc
- Stainless, mild or galvanised steel
- Glass and ceramic tiles
- Glass reinforced plastics
- Fibre reinforced cement sheetings
- Timber, particleboard, hardboard and plywood (refer to Limitations section)
- Butylclad rubber products - chase sealing
Advantages
- Good primerless* adhesion to most common building materials
- Paintable any time after curing, with water-based paints (compatibility testing recommended prior to full application)
- Will not stain masonry, marble or other surfaces
- Very durable - BRANZ appraised
- Neutral cure
- Highly flexible
- Low odour
Packaging
300 ml cartridges / 12 per carton
600 ml sausage unipacs / 20 per carton
Colour
300 ml cartridges | Grey, White, Black, Bronze, Ivory and Titania |
600 ml sausage unipacs | Grey, White |
Product Details
APPROVALS / STANDARDS
BRANZ Appraised, Appraisal No. 311 (2024)
ISO 11600:2002 Class F-25LM. Certified
ASTM C920-18. Compliant
NZ Building Code Compliant
- B2 Durability: Clauses B2.3.1 (b) 15 years. (c) 5 years
- E2 External Moisture: Clause E2.3.2
- F2 Hazardous Building Materials: Clause F2.3.1
Chemical Base
Moisture curing Silane Modified Polymer (SMP)
Shelf Life
Twelve (12) months from date of manufacture if stored correctly as stated.
Storage Conditions
Store in original, unopened packaging in cool, dry conditions protected from direct sunlight and at temperatues between +5°C and +25°C.
Density
~ 1.40 kg/l | (ISO 1183-1) |
Shore A Hardness
~ 15 (after 28 days) | (ISO 868) |
Movement Capability
± 25 % | (ISO 9047) |
Chemical Resistance
Good to dilute acids and alkalis
Resistance to Weathering
Excellent UV resistance
Service Temperature
-40°C to +90°C
Joint Design
Weather Seals
Weather seal joints within the structure must be designed to take into consideration the joint dimensions required to accommodate any anticipated cladding movement and the movement capability of the sealant.
- The joint width for weather seals shall be greater than 10mm and less than 35mm. For wider joints refer to Sika for assistance
- Joints must be designed to accommodate a width to depth ratio of 2:1 and where appropriate the sealant shall be applied onto a suitably sized Sika PEF Backing Rod which has been pre-installed to form the base of the joint.
- As an exception to the above, refer to the table below for standard dimensions for joints between concrete cladding elements: This ratio is subject to these overriding minimum sealant depths:
Joint distance [m] | Min. joint width [mm] | Min. joint depth [mm] |
2 | 10 | 10 |
4 | 15 | 10 |
6 | 20 | 10 |
8 | 30 | 15 |
10 | 35 | 17 |
Air Seals
This product meets the requirements of NZBC E2/AS1 Clause 9.6.1 AirSeals. Use it to provide a flexible air seal around doors, windows, penetrations, or openings within the cladding system, to minimise the risk of airflow carrying water into the building wall.
- The minimum joint dimension for air seals shall be 6mm wide x 6mm deep and where appropriate the sealant shall be applied onto a suitably sized Sika PEF Backing Rod which has been pre-installed to form the base of the joint.
Application
Curing Rate
~3 mm/24 hours (23°C / 50% r.h.) | (CQP 049-2) |
SUBSTRATE PREPARATION
Joint surfaces must be clean and free from frost and surface water. Remove all dirt, Iaitance, loose materials and foreign matter.
- Remove alI rust, scale and protective lacquers from metal surfaces.
- Non-porous surfaces should be degreased using Sika Thinner C
- In all joints a bond breaker must be used to prevent sealant contact with the back of the joint, and hence allow optimum performance. In shallow joints self adhesive polyethylene tape can be used. Deep joints should incorporate a backing strip such as Sika PEF Rod to support the sealant while also acting as a bond breaker.
PRIMING
Sikaflex® MS adheres to many substrates without primers and/or activators. However, for optimum adhesion and critical, high performance applications, such as on multi-story buildings, highly stressed joints or extreme weather exposure, the following priming and/or pretreatment
procedures shall be followed:
Non-porous substrates
Aluminium, anodised aluminium, stainless steel, PVC, galvanised steel, powder coated metals or glazed tiles have to be cleaned and pre-treated using Sika® Aktivator- 205, wiped on with a clean towel. Before sealing, allow a flash-off time of > 15 minutes (< 6 hours).
Other metals, such as copper, brass and titanium-zinc, also have to be cleaned and pre-treated using Sika® Aktivator-205,wiped on with a clean towel. After the necessary flash-off time, use a brush to apply Sika® Primer-3 N and allow a further flash-off time of > 30 minutes (< 8 hours) before sealing the joints.
Porous substrates
Concrete, aerated concrete and cement based renders, mortars and bricks shall be primed using Sika® Primer-3 N applied with a brush. Before sealing, allow a flash-off time of > 30 minutes (< 8 hours).
For more detailed advice and instructions please contact the local Sika Technical Services 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 TOOLS
Clean tools immediately after use with Sika Thinner C, or Sika Wonder Wipes.