We Supply St Astier and Lafarge natural hydraulic lime conforming to EN459-1. Natural hydraulic lime is used to make breathable durable lime mortars, lime plasters and lime renders for historic buildings and new buildings.
Natural hydraulic lime NHL 2 is the weakest strength natural hydraulic lime, suitable for most lime mortars, lime plasters and lime renders.
Natural hydraulic lime NHL3.5 is a medium strength natural hydraulic lime, suitable for lime mortars for brick laying and pointing, lime plasters and lime renders in moderate to high exposure locations.
Natural hydraulic lime NHL5 is a strong natural hydraulic lime, suitable for lime mortars in high exposure locations, copings, ridge tiles, marine applications, flooring and below ground.
Lafarge NHL and St Astier NHL delivered nationwide. Please contact us for more information
Samples of mortar sent to The Lime Centre can be colour matched with either local sands for mixing with NHL on site or to a range of premixed coloured NHL lime mortars: Lime Mortar
Further analysis for compatibility to existing mortar will require a Mortar Analysis.
The NHL mortar should be more like a dough than a slurry. The longer the final mixing time, the more workable (fatter) the mortar will be.
Choose a well-graded sharp sand with the largest particle approx. 1/3 the size of the joint.
For a 9 to 10mm brick joint use a 0 to 3mm sand
For a larger joint of 15mm (usually stone or flint) use a 0-5mm sand.
The mix ratio of the mortar depends on the strength of the surrounding mortar, the strength of the bricks or stone and the location and exposure. A standard spec for an NHL3.5 mortar in medium bricks and stone could be 1 part St Astier NHL3.5 to 2.5 parts well graded sharp sand. For softer bricks the lime can changed to NHL2. A natural hydraulic lime mortar made with NHL2 will be weaker than one made with NHL3.5 but more durable than a lime putty mortar.
Do not use NHL mortar in temperatures less than 5 ºC or over 30ºC. Protect against the effects of drying winds, strong sunlight, rain and frost. In warm weather gently mist spray with water after application and cover if required with damp hessian sheets. In cool periods cover with protective sheeting, to avoid frost damage.
For advice on our services and products call us on
01962 713 636