Umafix

Umafix is a grey, ready-to-use, single component, thixotropic, compensated shrinkage, cementitious mortar based on special hydraulic binders, selected aggregates and specific additives. The product is very resistant and fast setting. The special formula of the product, when mixed with water, ensures good workability and excellent thixotropy enabling even vertical application up to thicknesses of 40 mm. Once applied the product starts to set after approximately 20 minutes under normal conditions (20 °C). The time required for setting to start and final hardening is not subject to significant variations at lower temperatures. The hardened product is ready for loads after one hour and is resistant to water and frost. It is therefore ideal for indoor and outdoor applications and has a high level of impermeability. Umafix is a mortar designed for non-structural repairs. The product is type CC and in class R2 in compliance with EN 1504-3. Umafix conforms to principles 3 (concrete restoration) and 7 (preserving or restoring passivity) using methods 3.1 (applying mortar by hand), 7.1 (increasing cover to reinforcement with additional cementitious mortar or concrete) and 7.2 (Replacing contaminated or carbonatated concrete) in compliance with EN 1504-9.

Instructions for use

Preparation
The substrate must be solid and regular but well keyed, clean, in good condition and without any oil, grease, dust, loose material, dirt of any kind and any traces of old paint. The surfaces must also be sufficiently cured and free of significant shrinkage. Hammer and scrape the substrate to remove all loose, crumbling or non-cohesive material until a clean, resistant surface is revealed. Wet the surface to be treated until it is saturated and let the excess water evaporate or remove it with a sponge. Make sure you remove all the surface water.

Mixing the product
Mix Umafix with 17 – 18 % clean water (4,25 – 4,50 litres per 25 kg bag and 0,85 – 0,90 litres per 5 kg bag) using a mechanical mixer (low-speed drill with mixer attachment) until the mixture is smooth and free of lumps. The mixture prepared in this way has a pot life of about 15 minutes under normal conditions (20 °C). Higher temperatures reduce pot life. Always prepare quantities of mix which can be used within the pot life. Umafix is not subject to significant variations in setting times at low temperatures. In the event of low temperatures (around +5 °C), mix with warm water or keep the product in a heated room to maintain the same setting times. In the event of high temperatures (around 30 °C), mix with cold water and keep the product in the shade.

Application
Apply the mix quickly using a trowel or paddle. As soon as the mortar starts to set, wet the surface and smooth with a float. Keep the mortar moist for the first 8 hours after application. To fill large cavities, mix 10 kg of Umafix with approximately 5 kg of sharp sand. Firstly apply a keying coat of Umafix mixed with Neoplast Latex diluted in water (1 part product to 2 parts water) to obtain the consistency of a grout that can be applied with a brush.

Proceed as follows when restoring reinforced concrete:

• expose the outcropping reinforcing bars by completely freeing them from any carbonated concrete and turning them to “white” using a hydro-sandblaster or sandblaster.
• For effective anticorrosive protection, apply Restauro Ferri to any reinforcing bars present. After the anticorrosive protection has hardened, for better bonding of the Umafix coating apply a slurry of Umafix mixed with a 1:3 Neoplast Latex-water solution (1 part by volume of Neoplast Latex and 3 parts by volume of water) to the treated irons and surrounding concrete.
• On the fresh grout apply Umafix mixed only with water and possibly diluted with sand in the case of large cavities. As soon as the grout sets moisten the surface and finish with trowel.
• Keep the applied mortar moist in the first 24 hours.

Cleaning
The tools used for applying the mortar may be cleaned with water before it hardens. Once hardened, the mortar must be scraped off.

Storage

Store Umafix in a dry, protected place. Unopened in its original bags, the product can be stored for at least 6 months.

Warnings

• Do not use Umafix as foundation mortar for glass cement components.
• Do not apply Umafix on gypsum substrates or over gypsum based mortars, renderings and fillers.
• Do not apply Umafix on plastic renderings, painted substrates, wood or asbestos cement.
• Do not apply Umafix when the temperature is less than +5 °C and more than +35 °C.
• Do not mix the product with other binders such as cement, hydraulic lime, gypsum, etc.
• The mix cannot be diluted with water once it has started setting.
• Do not use the mixed product when it has already started to set. Therefore, always prepare quantities of mix which can be used within the pot life.
• Do not use the product for large-scale applications.