Choosing the Right Adhesive for Decking Applications: A Close Look at SMP45 and the Silca System
When it comes to structural decking solutions—especially those involving non-traditional surface materials like natural stone, porcelain tiles, or turf—adhesive performance plays a critical role. The choice of adhesive can impact everything from load distribution to weather resistance and long-term durability. In this article, we examine the different adhesive technologies available in the construction sector and explain why SabreBond SMP45 is the recommended product for use with the Silca System.
Understanding the Adhesive Landscape
There are four main categories of adhesives commonly used in construction and exterior decking applications:
- Solvent-Based Adhesives: Known for fast curing and strong initial grab, but often carry high VOCs and poor UV resistance.
- Water-Based Adhesives: Environmentally friendly and easy to use, but generally not suitable for exterior or structural applications due to low bond strength under moisture and temperature fluctuations.
- Polyurethane Adhesives (PU): High strength and flexibility, but prone to bubbling and yellowing under UV exposure, and sensitive to moisture during curing.
- Silyl-Modified Polymer Adhesives (SMP): The newest class offering a balance of flexibility, weather resistance, and low VOC emissions. Ideal for construction environments where long-term reliability is essential.
Why SMP Adhesives Are Ideal for the Silca System
The Silca System is designed to support a wide range of non-structural finishes over timber or aluminium joists. This includes tile, heavy-duty pavers, natural stone, and artificial turf—all of which demand a secure bond that resists wind uplift, temperature shifts, and moisture ingress. SMP adhesives outperform traditional options by offering:
- Excellent adhesion to diverse surfaces including plastics, ceramics, concrete, and metal
- High elasticity to accommodate movement and vibration without cracking
- Low shrinkage and bubbling during cure
- UV and weather resistance for outdoor longevity
- Solvent-free formulation—safer for installers and better for the environment
SabreBond SMP45: Field-Tested and Approved
SabreBond SMP45 is the specified adhesive for the Silca System in New Zealand and Australia. Unlike conventional construction adhesives, SMP45 has been specifically tested for outdoor use in structural paving support systems. Its properties include:
- High dynamic tensile strength for secure bonding under load
- Wind uplift performance validated through real-world testing
- 25-minute skin time and optimal open time for accurate placement
- Temperature resistance from -40°C to +100°C (short-term to 120°C)
- Low modulus for movement accommodation without stress cracking
Real-World Use: Application Considerations
SMP45 is typically applied in beads or ‘dob’ formations directly under tiles or pavers once laid over Silca Grates. The recommended coverage rate is approximately 1 600ml sausage per 2 square metres to ensure full coverage, especially when factoring in domed application patterns for superior grip.
Whether Silca System installed over joists or on adjustable pedestals for membrane decks, the SabreBond SMP45 adhesive provides a reliable seal and bond layer that complements the Silca System’s structural function and compliance with AS/NZS1170.1 and E2/AS1 building standards.
Conclusion
For high-performance deck systems like the Silca System, specifying the correct adhesive is not just a technical detail—it’s a critical factor in ensuring the longevity, safety, and performance of the entire surface. SabreBond SMP45 stands out in the market as a modern, robust, and purpose-formulated adhesive solution, aligning perfectly with Silca’s standards for durability, design flexibility, and structural confidence.
Download Supporting Documents:
For supply or installation support, contact your Silca distributor or visit silcasystem.co.nz.
