UNILIT 1320 (TD 13/20) BEDDING AND POINTING MORTAR
Outline specification : masonry, pointing
Product Description
Unilit 1320 is a traditional, dry premixed mineral bedding and pointing mortar based on natural hydraulic lime as the binder and appropriate well-graded lightweight aggregates.
Unilit 1320 is characterised by a slow but strong bonding, a high plasticity, a low content of soluble salts and an excellent water vapour permeability.
The natural hydraulic lime mortar is inherently stable and designed to reduce problems of micro cracks along with premature drying out.
The natural hydraulic lime binder, used to prepare the preblend, conforms to the European Standard EN 459-1, NHL 5 for building limes. The mortar Unilit 1320 conforms to the European Standard UNI EN 998-1.
Application Area
Unilit 1320 is especially suited for the application as a bedding and/or pointing mortar for highly porous substrates, such as lightweight insulating blocks, silicate or gypsum blocks, cellular concrete, etc.
Thanks to its natural pore structure and low content of soluble salts, Unilit 1320 regulates the moisture content within the masonry, eliminating practically all known problems related to frost, salt damage and lime bloom, providing that excessive damp and/or salt problems are not prevelant, and that the substrate is stable.
Application
Prior to application, the substrate must be cleaned and freed of all traces of oil and grease. The substrate benefits from being slightly dampened. Saturation of the substrate is not recommended, as this will influence negatively impact upon the bond of the hydraulic lime mortar to the substrate as well as the aesthetic appearence.
The mortar is mixed with clean water at a ratio of 4 to 5 litres of water to a bag of 30 kg ready mixed natural hydraulic lime powder. Mixing is undertaken with a slow speed electric paddle for a period of 3 to 5 minutes. A creamy workable mortar is obtained, which has approximately 2 hours of open time.
The wall or stonework is laid down with a nominal joint width of 8 to 10 mm. After laying the bricks or stones the mortar is pressed firmly within the joint with a pointing iron and finished off simultaneously. At the end the masonry surface is cleaned with a soft brush in order to remove all excess mortar remains. A drying period of 1 to 2 days must be respected.
The mortars must not be applied at temperatures below +5°C nor when a risk of frost exists. They should never be applied on to a frozen surface or in the case of thick fog. In hot, windy and dry conditions measures should be taken to prevent accelerated drying out of the freshly applied mortars. Applied mortars must be protected from frost and direct sunlight for 48 to 72 hours after their application.