Hybrid Polymer Sealants Buyer's Guide — TradieCart
Hybrid polymer sealants — also called MS polymer, SMP or SMX sealants — combine the flexibility and weather resistance of silicone with the paintability and adhesion of polyurethane, without the drawbacks of either. They're isocyanate-free, solvent-free, UV stable and can be painted or overcoated with waterproofing membranes once tack dry. We stock over 90 products from Durotech, Soudal, Crommelin, Pasco, Roberts Designs, Laticrete, Bostik, GSA and more.
Hybrid Polymer vs Other Sealants
| Feature | Silicone | Polyurethane | Acrylic | Hybrid Polymer |
|---|---|---|---|---|
| Paintable | No | Yes | Yes | Yes |
| UV Resistance | Excellent | Good | Poor | Excellent |
| Movement | ±25% | ±12–25% | ±7.5% | ±20–50% |
| Primer-Free Adhesion | Limited | Often needs primer | Limited | Excellent — most substrates |
| Isocyanate Free | Yes | No | Yes | Yes |
| Staining Risk | Yes (silicone oil) | No | No | No |
| Membrane Compatible | Poor — membranes won't adhere | Fair | Fair | Excellent — overcoat when tack dry |
| Damp Substrate | No | No | No | Yes |
Popular Products
| Product | Best For |
|---|---|
| Durotech Duroseal Hybrid 50FC | The go-to all-rounder — ±50% movement, fast curing, highly rated by tradies. Ideal for expansion joints, facades and waterproofing fillets |
| Soudal SMX35 Seal & Stretch | Versatile mid-range sealant — ±20% movement, Shore A 35. Concrete Grey is potable water approved. Popular for joints under waterproofing membranes |
| Crommelin Hybrid MS Polyurethane | Zero VOC, acoustic rated, ±25% movement. Strong choice for green-rated buildings and noise-sensitive applications |
| Laticrete Hydro Ban Fillet Sealant | Purpose-built for waterproofing fillets under Hydro Ban membrane — fast cure, no shrink. Ideal for bathrooms, showers and wet areas |
| Pasco Pascoflex Hybrid 25 | 9 colours for colour matching, ±25% movement, 450% elongation. Can be overcoated immediately with Pasco water-based membranes |
| Roberts Trade Grade Hybrid Sealant | 10 colour options, available in boxes of 12. Cost-effective for larger sealing jobs where colour matching matters |
| Soudal T-Rex Fast Grab | Instant-grab hybrid adhesive — holds 320 kg per 10 cm² with 1-second grab. Ideal for bonding panels, trims, mirrors and heavy fixtures |
| Soudal T-Rex Power Crystal | Crystal clear hybrid adhesive/sealant — food safe, mould resistant. Best for visible bonds and sanitary applications |
Quick Recommendation Guide
- Expansion joints & facades → Durotech Duroseal Hybrid 50FC — highest movement accommodation (±50%), fast cure, excellent tradie feedback
- Joints under waterproofing membranes → Soudal SMX35 or Laticrete Hydro Ban — both can be overcoated with liquid membrane once tack dry (as fast as 10–30 minutes)
- Bathroom & shower fillets → Laticrete Hydro Ban Fillet Sealant — specifically designed for wet-area waterproofing transitions
- Colour-matched sealing → Pasco Pascoflex Hybrid 25 (9 colours) or Roberts Trade Grade (10 colours)
- Heavy-duty bonding → Soudal T-Rex Fast Grab — 320 kg hold, instant grab, paintable
- Invisible/clear bonds → Soudal T-Rex Power Crystal — crystal clear, food safe
- Green Star / low VOC projects → Crommelin Hybrid MS Polyurethane — zero VOC, isocyanate free
- Bulk orders for large jobs → Roberts Trade Grade Hybrid — boxes of 12, 10 colour options
Common Questions
What is the difference between MS polymer, SMP and SMX sealants? — They are all names for the same hybrid polymer technology. MS stands for Modified Silane, SMP is Silyl Modified Polymer, and SMX is Soudal's proprietary branding. They all use a silane-modified polyether backbone.
Can I paint over hybrid polymer sealants? — Yes. Most can be painted with water-based paints once the surface has skinned over (typically 10–45 minutes depending on the product). This is one of their biggest advantages over silicone.
Can I apply waterproofing membrane over hybrid polymer sealant? — Yes. Liquid waterproofing membranes adhere directly to hybrid polymer sealant fillets once tack dry — typically within 10–30 minutes for products like Soudal SMX35. This is much faster than silicone, which requires full cure (24–48 hours) and membranes still struggle to adhere. Hybrid polymers are the preferred sealant for waterproofing fillet applications under AS 3740.
Should I use Durotech Duroseal 50FC or Soudal SMX35? — The Durotech offers higher movement accommodation (±50% vs ±20%) and faster curing, making it the better choice for expansion joints and high-movement applications. The SMX35 is a solid mid-range option with potable water certification (Concrete Grey) — choose it when you need water-contact approval or a more cost-effective solution.
Do hybrid polymer sealants need a primer? — In most cases, no. They bond directly to concrete, masonry, timber, metal, glass, COLORBOND, fibre cement and most plastics without a primer. Always check the product datasheet for specific substrate exceptions.
What temperature range can hybrid polymer sealants handle? — Most products perform from −40 °C to +90 °C in service. Application temperature is typically 5 °C to 40 °C. They are not suitable for high-heat applications above 90 °C — use silicone for those jobs.
Brands We Stock
We carry hybrid polymer sealants from Durotech, Soudal, Crommelin, Pasco, Roberts Designs, Laticrete, Bostik, GSA, HB Fuller, Antas, Integra, Maxisil, Ardex, Kerakoll, Keratrade, WSS, Demtech, RLA, SA and Wedi. Products range from general-purpose joint sealants to specialist waterproofing fillets, instant-grab adhesives and facade sealants — all available with same-day Metro Melbourne dispatch.