Cement Screed A cement and sand screed finish to a concrete floor may be an acceptable, low cost finish to small area floors of garages, stores and outhouses where the small area does not justify the use of a power float and considerations of ease of cleaning are not of prime importance.
Fibre Reinforced Cement Screed Premixed, dry bagged cement and sand screed material reinforced with polymer fibre is available. The fibre reinforces against drying shrinkage and cracking. Cement + Sand Thickness: mm It is the base for upper covering materials.
Laying Screed The traditional method of screeding a large area is to divide the floor up into bays not exceeding 3.5 m in width. The bays are laid alternately working to screeding battens which have been carefully levelled and aligned, and firmly bedded throughout their length. The first bays are left for 24 hours, then the battens removed and the remaining bays completed.
Terrazzo (in-situ type) Composed of a thin, stone-chip topping adhered to a mortar base or concrete slab, a terrazzo floor is divided into sections by thin divider strips that help to control cracking. Traditional terrazzo is composed of graded marble or aggregate (70% or more) in a cement matrix. Colour is often added to the cement matrix in order to highlight the stone aggregate, which itself is a mix of colours and sizes.
A terrazzo floor is divided into sections by strips, usually brass, zinc or plastic. The divider strips create weakened vertical planes inducing unavoidable cracking to occur at these locations. Maximum spacing of divider strips ranges from 120 cm to450 cm depending on the type of terrazzo system employed.
Ceramic Tiling A bed of semi-dry cement and sand, mix 1:4, is spread over the concrete or screed base and packed to a thickness of about 3,5 cm. the bed is then covered with a grout (wet mix) or cement and sand, mix 1:1, into which the tiles are bedded, levelled and the joints grouted or filled. The semi-dry bed accommodates relative movement between the base and the tiles.
To take up possible expansion of tiles an expansion joint should be formed around the perimeter of a tiled floor. The joint is filled with an elastic sealing compound. For large areas of tiled floor, additional expansion joints should be formed both along and across the floor with grout of cement or a mix of cement and fine sand.