Roundtower Marine LP6 Mortar
Roundtower Marine LP6 Mortar is a ready-mixed natural cement mortar developed for building, bedding, and pointing masonry in marine and water-bearing environments. Manufactured using Natural Cement and selected natural sands, it provides rapid strength development, excellent adhesion, and resistance to washout in damp, tidal, and submerged conditions.
Marine LP6 is the lowest-strength mortar within the Cornerstone Marine range and is specifically designed for very soft historic masonry where maximum compatibility is required. Its low compressive strength makes it particularly suitable for conservation projects involving fragile stone, soft brickwork, and traditional masonry exposed to coastal, tidal, or freshwater environments.
Technical Data
| Property | Value |
|---|---|
| Product Type | Ready-Mixed Marine Mortar |
| Binder | Natural Cement |
| Aggregate | Selected Natural Sands |
| Colour | Natural Tan |
| Application | External |
| Workability Time | Approx. 50 Minutes at 17°C |
| Yield | Approx. 14.5 Litres per 25kg Bag |
| Coverage | Approx. 1.5m² Pointing @ 10mm Depth |
| Compressive Strength | Approx. 6 N/mm² |
| Fire Rating | A1 |
| Standard | BS EN 998-2:2016 |
| Packaging | 25kg Bags |
Key Benefits
Ultra-Low Strength for Historic Masonry
Developed for fragile stonework and soft masonry where stronger mortars may cause damage.
Water Resistant
Suitable for masonry exposed to:
- Saltwater
- Freshwater
- Tidal action
- Wetting and drying cycles
Rapid Set
Develops strength quickly, helping reduce the risk of washout in exposed marine environments.
No Carbonation Required
Hardens hydraulically, allowing use in permanently damp and submerged conditions.
Sulphate Resistant
Suitable for coastal and marine environments exposed to aggressive salts.
Portland Cement Free
Contains no Portland cement, synthetic polymers, or pigments.
Typical Applications
| Application | Suitability |
| Soft Historic Masonry | ✓ |
| Heritage Pointing | ✓ |
| Coastal Conservation Projects | ✓ |
| Tidal Zone Masonry | ✓ |
| Harbour Structures | ✓ |
| Lock Walls | ✓ |
| Canal Structures | ✓ |
| Water-Bearing Masonry | ✓ |
| Submerged Masonry Repairs | ✓ |
Why Use Marine LP6?
Marine LP6 is designed for projects where compatibility with very soft historic masonry is the primary consideration. Its lower compressive strength helps minimise stress within traditional masonry while still providing the durability, water resistance, and rapid set associated with Natural Cement mortars.
This makes it particularly suitable for conservation work on vulnerable coastal and water-exposed structures where stronger marine mortars would be inappropriate.
Installation Overview
1. Surface Preparation
Substrates should be clean, sound, and free from loose material.
2. Mixing
Mix with clean water or clear seawater free from biological contamination, silt, and sand.
3. Application
Suitable for pointing, building, and bedding in marine and water-bearing masonry applications.
4. Protection
Do not apply below 5°C or above 30°C. Protect fresh work from frost, heavy rain, direct sunlight, and drying winds.
5. Storage
Store dry, covered, and protected from moisture and frost.
