SMET NHL 5 is a high-quality, pure, Natural Hydraulic Lime binder, produced under ISO 9001 and ISO 14001 management systems to EN 459-1. The eminent hydraulic strength development of SMET NHL 5 makes it suitable for producing lime mortars for masonry work, rendering, plastering base coats and limecrete in extreme weather environments and exposed areas.

An eminently hydraulic lime binder for the production of mortars particularly suited for ecological new build, restoration, and preservation works in extreme weather environments and exposed areas. The product’s special composition allows the mortar product to breathe and also permits constant hygrometric exchange between the substrate and the environment.

Related Downloads

icon-pdf  TDS SMET NHL 5

icon-pdf  SMET and Haldane Fisher NHL Brochure

NBSplus NBS Specification Clause

BIM BIM Objects

Benefits of SMET NHL 5 Binders

• Historical, gypsum and cement-free NHL
• Produces highly breathable mortars
• Highly sulphate resistant
• Low-stress hardening process
• Excellent subsequent hardening
• High water retention and elasticity in produced mortars
• Excellent bond properties to masonry
• EN 459-1

Production Of Mortars For Masonry

Binder: sand ratio: from 1: 1.5 to 1:3 depending on site and material conditions, joint size and sand grading. Always use well graded clean sands (3 – 4mm down to 75 microns).

Production Of Mortars For Rendering

1. Scud Coat (3-5 mm) Binder: Sand ratio: 1: 1.5
2. Base Coats  (10 mm) Binder: Sand ratio: 1: 2
3. Finish Coat (5-10 mm) Binder: Sand ratio: 1: 2.5


SMET NHL 5 must be mixed with clean, well-graded sands and clean water without additives. Do not mix or apply if the temperature is below +5ºC or over 30ºC. This product must not be mixed with gypsum or be applied to gypsum-based substrates. Avoid over-mixing, as this can adversely affect performance and strength. Material that has set must not be re-mixed. For interior applications, care must be taken when using heating systems. High or rapidly changing temperatures may affect the hydraulic setting reaction of the mortar/render and cause cracking and/or adhesion problems. Delay the implementation of heating systems for as long as possible and heat up interiors gradually. Other unfavourable conditions, such as overly wet backgrounds, low background temperatures, and low air temperatures can delay setting. During and after application, protect the mortar/render from adverse weather conditions, such as direct sunlight, strong winds, rain, and frost.


Technical Details for SMET NHL 5

UnitAverage values*Conformity to Standard
Physical PropertiesMiniMaxi
Fineness at 90 µ%42
Fineness at 200 µ%1.32
Bulk densityg/cm32.75
Real densityg/cm38856
Blaine valuecm²/g0.912
Water content%
Mechanical Properties14260
Beginning of setmin191900
End of setmin2.652
Mechanical strength at 28 daysMPa5.34515
Chemical Properties
Free lime content%18.515

Packaging: Available in 25 kg bags.


Also available in designation: SMET NHL 2 and SMET NHL 3.5

Read more about our NHL Binders in use

SMET NHL articles