St Astier Stone Restoration and Repair Mortar

St Astier Natural Hydraulic Limes (NHL)

Specially formulated mortar based on Natural Hydraulic Lime and aggregates for the repair or simulation of masonry, brick or stone. St Astier stone repair mortar is a neutral white or pre coloured mortar supplied in 1KG to 25KG bags to which mixing water is added. Mixing and use: Can be mixed manually or mechanically by whisk, adding up to 180ml water per kilogram of stone repair mortar used. Mix well for 3-5 minutes. The application surface must be clean, free from dust and oils. On porous surfaces, ensure that suction is controlled by pre-wetting and apply repair mortar before this is fully dry. Never apply to surfaces that are over saturated or have standing water. It can also be applied on metal laths. For application on dense impervious materials, please consult us.

The minimum thickness is 5mm (can be dressed or cut back to a feather edge). The maximum thickness in 1 pass is 40mm. In cases where a thickness of more than 40mm is required, apply in layers of a maximum of 40mm, each one approximately 24 hours apart. Always dampen application areas. The mortar should be well pressed back in place. If required re-compact by pressing after a couple of hours to avoid possible shrinkage marks due to suction from the background. In some instances support of the fresh mortar is required by using wires, anchorages, stainless steel fixings or formers, etc... Simulation of stone / brick features, rough finishes, false joints etc. can be made approximately 5 hours from application (in damp cold weather up to 24 hours).

Shaping and forming of details can be carried out for up to 1 week after placing by scraping to profile or level with metal tools, such as the edge of a trowel or steel float however most shaping and finishing work can be done within 24 hours. Sculpting, using appropriate tools, requires waiting up to a week or more depending on the weather conditions. Its unique qualities allow it to be tooled, shaped and sculpted even after the final set has taken place. This affords sufficient time to achieve the very highest standard of work with the best quality reproduction.

Where ashlar masonry or very finely jointed masonry has had considerable damage to the arises, flush finishing in repair mortar with a false struck joint is the ideal solution.

If building details are damaged and require repair prior to the facade being lime washed or painted, stone repair mortar should be used as it will readily accept lime washes and paints.

On rendered areas stone repair mortar can be used to form decorative stone or brick features such as mouldings and cornices.

Technical Data

Bulk density:( kg/m3 ) : 1325 - 1360
Granulometry: from 0.8 to 0.08mm
Consumption: 1.6 to 1.7 kg. per m2 per mm. of thickness

Setting time (in water with no surcharge): start 1h30min / end 2h30min. Tests on paste (water addition 18.7%)