Expancell Product Description
Non-absorbent and rot-resistant. The performance of
Expancell is unaffected by extreme weather conditions.
Economical, easy to install, easily compressible, rot-resistant, and non-absorbent. It acts as a bond breaker and helps maintain an optimal low-stress profile for joint sealants, providing firm support for sealant tooling.
Uses
Expancell is a Closed Cell Polyethylene Foam manufactured in the form of a round cord for use as a back-up material in joint sealing applications.
Expancell is available in a wide range of diameters, from 6 mm to 50 mm, making it suitable for various joint sizes commonly found in construction applications.
Advantages
Economical and cost-effective
Easy to install
Easily compressible
Rot-resistant and non-absorbent
Acts as a Bond Breaker and helps maintain the appropriate sealant profile to minimize stress within the sealant material
Provides firm backing, allowing convenient tooling and finishing of the sealant surface
Description
Expancell is a Polyethylene Foam Back-up Cord designed for joint sealing applications and performs several functions.
The product helps maintain the correct width-to-depth ratio of sealant joints and provides firm backing to facilitate effective sealant tooling.
These properties help ensure that the sealant makes proper contact and adheres closely to the joint sidewalls during installation, resulting in good adhesion.
In addition, Expancell acts as a Bond Breaker at the bottom of the joint, preventing the sealant from adhering to all three surfaces (Three-Sided Adhesion), which could generate additional stress within the sealant when joint movement occurs.
Expancell is non-absorbent and rot-resistant, and its performance is unaffected by extreme climatic conditions.
Properties
| Property | Description |
|---|---|
| Form | Compressible, closed-cell foam in round cord form |
| Durability | Excellent |
| Dimensional Stability | Excellent |
| Water Absorption | Negligible |
| Colour | Grey |
| Temperature Stability | -40°C to +60°C |
Design Criteria
Example of an expansion joint detail sealed with a sealant, showing the installation position of Expancell Back-up Cord.
Sealant
Expancell Back-up Cord
Instructions for Use
Expancell is generally installed by pressing the round foam cord into a clean, dry, and dust-free joint.
If necessary, a blunt tool may be used to press the material into the joint. However, care must be taken to avoid damaging the surface of Expancell.
The diameter of the back-up cord should be approximately 20–25% larger than the joint width to ensure that the material is compressed and held securely in position.
Installing the appropriate cord size helps maintain the specified depth-to-width ratio of the sealant joint.
In addition, the firm backing allows the sealant surface to be tooled and finished neatly, resulting in a more aesthetically pleasing joint finish.
Once installed, the circular cross-section of Expancell creates a Convex Face, which helps Elastomeric Sealants achieve an optimal profile for minimizing internal stress within the sealant material.
Technical Support
Fosroc provides comprehensive technical support services to designers, specifiers, users, and construction contractors.
The company also offers On-site Technical Assistance, AutoCAD drafting services, and specialized Specification Assistance for product specifications and technical requirements in various locations worldwide.
