Roundtower Lime Putty is a premium, high-purity binder made from high-calcium quicklime sourced from Buxton, Derbyshire, and slaked in the traditional way—stored in pits and matured for a minimum of four months. This careful process ensures complete hydration and results in a fat, highly workable putty with a bulk density of approximately 1350 kg/m³.
Understanding lime putty density is essential: lower-density putties have higher water content and reduced available lime, which may require adjustments when used in mortars or plasters.
✔️ Available Sizes: 25kg tubs, and bulk bags
✔️ Bulk Density (RBD): ~1350 kg/m³
✔️ Guaranteed Maturation: Minimum of 4 months
✔️ Binder Type: Pure non-hydraulic lime (calcium hydroxide)
Traditional Applications
Historically, lime putty was used primarily in renders and plasters, matured to allow complete conversion of calcium oxide to calcium hydroxide. Traditional mortars were often hot-mixed, using freshly slaked lime and sand. While suitable for many conservation works, lime putty should be carefully selected for appropriate use cases to avoid site distress, especially where conditions are damp or exposure is high.
Modern Use Considerations
Today, lime putty remains a favoured binder for heritage plasters, pointing mortars, and decorative finishes where maximum vapour permeability is required. However, due to its reliance on carbonation rather than chemical setting, aftercare is critical, especially in cooler or wetter conditions.
Advantages
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Produces the finest lime plasters with unmatched finish and workability
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Yields fatty, easy-to-use mortars, plasters, and renders
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Offers exceptional breathability, ideal for solid-walled historic buildings
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Matured for 4+ months to ensure stability and performance
Limitations
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Not suitable for wet or damp environments due to lack of hydraulic set
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Requires good curing conditions – must be protected from frost, extreme heat, or excessive moisture
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Best used seasonally – outdoors only from April to October, following the old builder’s rule: “only when the swallows are home”
Professional Advice
Lime putty remains a specialist material, best suited for conservation projects, traditional plastering, and interior fine work. If you're unsure whether putty is appropriate for your application—particularly for external work or damp environments—contact our technical team for advice on the most suitable lime binder.
Delivery - We are unable to send Lime Putty via couriers due to an increase in damages. All lime putty orders need to be via pallet.
