Roundtower NHL 3.5 Fine (Premix)Roundtower NHL 3. 5 Fine (Premix) Roundtower NHL 3. 5 Fine is a ready mixed lime mortar manufactured from Natural Hydraulic Lime (NHL 3. 5) 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 durability, vapour

It will seal the gap between a window or door frame and the wall or a Pro Clima membrane and a wall to ensure there will be no air leakage

Windtight Outer Layer

🔹 Heritage Brick & Stone Restoration – Ideal where sensitive hand tools are required to protect original materials

Reinforcement & Finishing

STEICO Universal is a rigid wood fibre insulation board designed for use as a sarking board in pitched roof constructions and as an external sheathing board in timber frame wall systems

essential for long-lasting timber structures

Prompt remains vapour open and compatible with lime-based construction while offering extremely rapid setting

off the ground

no irritation compared to man-made fibres

This means the possibility of shrinking (retraction) to cause air or moisture leaks is greatly reduced

Conventional cement renders often trap moisture and can accelerate deterioration in damp masonry

Visconn Fibre offers a robust long-term flexible seal that can be paint applied to fill gaps of up to 20mm in width