At Roundtower Lime, we supply a premium range of premixed lime mortars tailored for traditional building, historic conservation, and breathable eco-construction. Whether you're repointing masonry, bedding stone, or repairing brickwork, our pre-blended mortars ensure consistency, quality, and long-term performance.
Our selection includes Natural Hydraulic Lime (NHL) mortars as well as Non-Hydraulic (Lime Putty) mortars, expertly formulated to match traditional building methods while meeting modern technical expectations.
Each mix is carefully prepared in-house or by trusted European partners to meet the highest standards, using clean graded sand and matured lime binders—removing the margin for mixing error on-site.
Our Range of Premixed Lime Mortars Includes:
Natural Hydraulic Lime (NHL) Mortars
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Available strengths: NHL 2, NHL 3.5, and NHL 5
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Perfect for repointing, bedding, and general masonry work
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Offers faster setting, higher compressive strength, and reliable durability
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Remains breathable and flexible—ideal for solid masonry and heritage repairs
Non-Hydraulic Lime Putty Mortars
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Made from matured lime putty and sharp, well-graded sands
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Traditional slow-setting mortar for fine pointing and delicate restoration
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Exceptionally breathable, soft, and flexible—ideal for older stone or brickwork
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Available in a range of sands and tones to match regional or historic requirements
Why Choose Premixed Lime Mortars from Roundtower Lime?
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✅ Ready-to-use formulations for convenience and consistency
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✅ Ideal for heritage building, restoration work, and eco-retrofits
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✅ Pre-blended to strict ratios—just mix with water and apply
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✅ Custom mortar matching available upon request
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✅ Available in bulk, tubs, or bagged options for site flexibility
Frequently Asked Questions (FAQ)
What is the difference between NHL mortar and lime putty mortar?
NHL mortars set through a hydraulic reaction with water and are better suited to exterior or structural use. Lime putty mortars set slowly by absorbing carbon dioxide and are ideal for delicate, breathable finishes and internal conservation work.
Which mortar should I use for repointing historic masonry?
For most soft or historic masonry, we recommend NHL 2 or a lime putty mortar, depending on the wall's condition and exposure level. NHL 3.5 can be used for slightly harder or more exposed conditions.
Are premixed mortars more reliable than site-mixed ones?
Yes. Premixed mortars eliminate variability in mixing ratios and sand grading. This ensures consistent performance, curing, and visual finish—especially critical in conservation projects.
Can I colour match the mortar to my existing building?
Absolutely. We offer custom colour and sand blends to closely match historic mortars. Our team can assist with samples and visual comparisons.
Do premixed mortars comply with conservation standards?
Yes. Our products are suitable for listed buildings, protected structures, and conservation-approved works. All mortars are breathable, lime-based, and free of cement or synthetic additives.
