Plaster Mortar NHL 5 is a free-flowing, cement-free mortar in powder form for reconditioning and consolidating masonry made from natural hydraulic lime,, fine natural sand, special additives and micro-fibers with very low emission level of volatile organic compounds. This product is classified G according to EN 998-1 Standards: “Guaranteed performance, general purpose masonry mortar for external and internal”, class CS II. When mixed with water Plaster Mortar NHL 5 forms a thixotropic, volumetrically-stable, salt-resistant mortar which is easy trowable with large internal gaps and cavities without sagging. Once hardened, the characteristics of the mortar made from Plaster Mortar NHL 5, such as mechanical strength, modulus of elasticity and porosity, are very similar to those of the mortar made from lime, lime-pozzolan or hydraulic lime originally used in the construction of old buildings. Plaster Mortar NHL 5 also has properties which make the product resistant to various chemical-physical aggressive phenomena, such as the presence of soluble salts and alkali-aggregate reactions. Besides, the mortar does not induce the formation of efflorescence and does not release soluble salts. Plaster Mortar NHL 5 is recommended for layers up to 3 cm thick.
Field of Application
• Internal and/or external macro-porous, de-humidifying render on masonry, including recent builds, with capillary rising damp and saline efflorescence.
• New de-humidifying render or reintegrating old lime and natural hydraulic lime-based render on stone, brick, tuff, and mixed masonry, including on buildings with a protection order from a local Heritage Organisation or situated within a sustainable building zone.
• Dehumidifying renders for masonry in lagoon areas or close to the sea.
• Restoring damaged render on buildings built using low-performance mortar.
• Pointing “exposed finish” stone, brick, and tuff masonry.
COVERAGE / CONSUMPTION
Preparation of the substrate
• Remove all deteriorated and loose concrete to form a solid, rough and strong substrate. Any areas previously repaired and which are not perfectly bonded must also be removed.
• Remove all dust, rust, cement laitance, grease, oil and paint from the concrete and reinforcement rods by sandblasting or hydro-sandblasting.
• Treat reinforcement rods with Ferroprimer 1K or 2K, according to the procedure given in the Technical Data Sheet of product.
• Saturate the substrate with water.
• Before carrying out repairs, wait until excess water has evaporated.
• Install the frame works.
Preparing the product
Mix Plaster Mortar NHL 5 in a cement mixer or in the hopper of a screw-type pump with a separate mixer, such as a Putzmeister S 5 or a similar machine. Small amounts of the product may be prepared using an electric drill at low speed with a mixing attachment. After adding around 3 litres of clean water for every 25 kg bag of product in a cement mixer or in the mixing unit of a screw-type pump, slowly add the powdered mortar in a constant flow. Mix for 3 to 4 minutes and then make sure the mix is well blended and even and that there are no lumps. Make sure there are no traces of powdered mortar stuck to the sides or bottom of the mixer.
Applying the product
Apply a layer of mortar from 20 to 30 m thick with a trowel or putty knife; no formwork is required. As soon as the mortar starts to set, tamp the surface with a sponge float. The waiting time required before carrying out this operation depends on surrounding weather conditions.