Cement screed LFS 70 is used for leveling bed for finishing overcoating of rigid concrete floors of industrial buildings and residential apartments by layer thickness till 60 mm. Cement screed LFS 70 can be applied for laying and repairing floors indoors and outdoors of buildings, for preparing beds for overtopping by self-leveling mortars or different coatings such as linoleum, carpet, laminate, parquet, ceramic tiles, natural stone and others. Screed ANSERGLOB LFS 70 is used for connective, separating, "floating" undercoats or floor heating systems.
The surface preparation is realized according to State Standard of Ukraine (DSTU N B A.3.1-23:2013) and State Building Codes of Ukraine (SNiP 2.03.13-88 and State Building Codes of Ukraine (DBN В.2.6-162:2010). Surface must be structurally sound, clean, dry and free from dust, grease, dirt, lime, wax, oil or emulsion paints. Before applying screed fragile areas of substrate must be removed. Cement surface is cleaned up from laitance by wire brush or sandblaster. Thus, it allows to increase adhesion of smooth surfaces. Cracks in the beds must be expanded and treated by one of deep penetrating emulsions ANSERGLOB and filled with ANSERGLOB LFS 70. Before applying substrates with strong sorption must be treated by one of deeply penetrating emulsions ANSERGLOB and exposed for 4 hours. Insufficient quality of preparing work can lead to delaminating or cracking of the laid layer.
Prepared screed mortar is laid on bed and spread on the surface with a shovel or other tool. Then it is compacted and smoothed by power tool (vibrating screed, vibrating plate compactor), or manually using feather edge, compacting with smoothing till full compaction (surface starts to gloss). When laying ‘floating’ floor thickness is 40 mm as minimum. When using as separating layer, application thickness is 35 mm as minimum. All works on the preparation, spreading and smoothing of each portion of mortar should be carried out for 2 hours. At breaks in work more than 2 hours tools and equipment must be cleaned from mortar and washed with water. Cured mortar can be removed only in mechanical way. When applying mortar and during curing to prevent cracking it is required to avoid of draught and fast drying of screed. .
Depending on the curing conditions, application thickness and residual moisture of bed (not more than 4%) further work should be done not less than after 7 days for the installation of ceramic and stone tile and 14 days for laying parquet, linoleum and carpet.
Note: Strength of bed must be not less than next layer. Application should be complied at temperature above +5°С and below +30°С. All the mentioned recommendations are effective at temperature of +20°С and air humidity of 60%. Under the other conditions crusting, stiffening and curing time may be changed.
Average consumption of the mixture is 1,8 kg per m2 at 1 mm layer thickness.
Dry mixture must be poured into container with clear water according to ratio 0,13-0,15 liters of water per 1 kg of mixture (3,25 - 3,75 liters of water per 1 bag of 25 kg) when at the same time manually or mechanically mixed (by the drill on low revs) to obtain the kindred and elastic mass. After exposing 5 min mortar must be mixed again and can be used. Excess quantity of water leads to reducing quality, decreases strength and can lead to delaminating that is unacceptable.