Roundtower NHL 2 Fine (Premix)
Roundtower NHL 2 Fine is a ready-mixed lime mortar manufactured from Natural Hydraulic Lime (NHL 2) and fine kiln-dried sand, blended in a controlled factory environment to provide a consistent, breathable mortar for fine pointing, plastering, and finish rendering applications. Supplied in a pre-blended 2:5 lime-to-sand ratio, it removes the need for on-site batching while maintaining the vapour permeability, flexibility, and compatibility associated with traditional NHL 2 mortars.
Designed for fine finish work, NHL 2 Fine is particularly suited to historic buildings, solid-wall construction, conservation projects, and breathable renovation work where moisture management and compatibility with traditional masonry are essential. Its finer aggregate grading makes it ideal for narrower joints, smoother finishes, and final render coats.
Technical Data
| Property | Value |
|---|---|
| Product Type | Ready-Mixed NHL 2 Lime Mortar |
| Binder | Natural Hydraulic Lime (NHL 2) |
| Mix Ratio | 2:5 (Lime : Sand) |
| Aggregate | 2mm Kiln-Dried Sand |
| Yield | Approx. 13.5 Litres per 25kg Bag |
| Render Coverage | Approx. 1.4m² @ 10mm Thickness |
| Brick Coverage | Approx. 25 Bricks per Bag |
| Water Addition | 4–5 Litres per 25kg Bag |
| Open Time | Minimum 8 Hours (Weather Dependent) |
| Standard | BS EN 998-1 & BS EN 998-2 |
| Packaging | 25kg Bags |
| Vapour Behaviour | Highly Breathable & Vapour Open |
Key Benefits
Ready-Mixed for Consistency
Factory-controlled blending ensures a consistent mix ratio throughout the project, reducing variability and improving reliability compared to site-mixed mortars.
Highly Breathable
Allows moisture vapour to move freely through the wall structure, helping traditional masonry dry naturally and reducing the risk of trapped moisture within solid-wall buildings.
Suitable for Fine Finishing
The fine aggregate grading makes NHL 2 Fine particularly suitable for:
- fine pointing,
- finish rendering,
- lime plastering,
- and narrow masonry joints.
Compatible with Traditional Masonry
The feebly hydraulic NHL 2 binder produces a softer and more flexible mortar than stronger hydraulic limes or cement mortars, making it suitable for:
- soft stone,
- historic brickwork,
- rubble masonry,
- and heritage buildings.
Excellent Workability
The combination of NHL 2 and fine graded aggregates provides good workability, smooth finishing characteristics, and extended open time during application.
Cement-Free Construction
Contains no Portland cement, helping maintain compatibility with traditional building materials and breathable construction methods.
Typical Applications
- Fine pointing stone masonry
- Fine brick pointing
- Internal lime plastering
- Finish render coats
- Heritage restoration
- Conservation projects
- Traditional solid-wall buildings
- Breathable renovation work
- Historic masonry repairs
Why Use NHL 2 Fine?
Roundtower NHL 2 Fine provides the same breathable and flexible characteristics as Roundtower NHL 2 but in a convenient ready-mixed format specifically designed for finer finishing work.
The fine aggregate grading makes it particularly suitable for:
- finish coats,
- fine pointing,
- decorative lime work,
- and smooth render finishes,
while the NHL 2 binder remains highly compatible with traditional masonry and conservation projects.
For historic buildings and breathable construction, NHL 2 Fine offers a practical solution where a finer finish is required without sacrificing vapour permeability or material compatibility.
Typical Applications by Use
| Application | Recommended Use |
|---|---|
| Fine Pointing | Narrow stone and brick joints |
| Finish Rendering | Fine float coats |
| Lime Plastering | Internal breathable plasterwork |
| Conservation Work | Heritage and listed buildings |
| Solid Wall Construction | Breathable masonry systems |
Installation Overview
1. Surface Preparation
Substrates should be:
- clean,
- stable,
- free from dust,
- and appropriately dampened before application.
2. Mixing
Add approximately 4–5 litres of clean water per bag and mix thoroughly. Allow the mortar to stand briefly before remixing and application.
3. Application
Suitable for:
- fine pointing,
- plastering,
- finish rendering,
- and decorative lime work.
4. Protection & Curing
Protect fresh work from:
- frost,
- heavy rain,
- rapid drying,
- and direct sunlight during curing.
5. Storage
Store dry, off the ground, and protected from moisture prior to use.
