Moisture-Curing Sub-base Binder
A single-component, solvent-free, moisture-curing polyurethane binder for stone aggregate sub-base preparation beneath resin bound surfaces.
No mixing of Part A/B — simple, ready-to-use formulation
100% solids content for maximum binding performance
Reacts with atmospheric moisture for reliable curing
16% NCO content for strong, durable aggregate binding
Foundation Binder is a single-component MDI-based polyurethane binder designed for binding stone aggregates in sub-base preparation for resin bound surfaces. Unlike the Spectrabind Clear and Gold systems which are 2-pack products, Foundation Binder is moisture-curing — requiring only atmospheric moisture to cure, with no Part A/B mixing needed.
This makes it simpler to use on site for base-coat preparation. Mix at 3.5-5% addition level with stone aggregate, with cure time approximately 3-6 hours depending on conditions. Recommended substrate temperature 10-25°C with humidity between 40-70%.
Avoid over-mixing to prevent premature curing. The product is solvent-free at 100% solids, with a viscosity of 4500-7000 mPa.s at 25°C. Shelf life is 6 months from manufacture when stored correctly in sealed containers.
| Type | Single Pack Moisture Curing PU (MDI-based) |
| NCO Content | 16% |
| Viscosity | 4500-7000 mPa.s at 25°C |
| Addition Level | 3.5-5% with stone aggregate |
| Cure Time | 3-6 hours |
| Substrate Temp | 10-25°C |
| Humidity | 40-70% |
| Form | Solvent-free liquid |
| Shelf Life | 6 months |
Full specifications, mixing ratios, and application guidance (PDF)
COSHH data, handling precautions, and safety information (PDF)
Our technical team can advise on the best binder for your project, application conditions, and aggregate choice.