Floor screed in Batumi: method and sign-off

What screed we lay and how thick

We choose the type of screed by what lies beneath it. A bonded screed holds onto a slab that has been cleaned of dust and primed, which is why it is the thinnest. Over waterproofing or an old floor with oil stains, a bond is either not needed or not possible, and the screed is laid on a separating layer of plastic sheeting. A floating screed lies on sound or thermal insulation and is not bonded to anything, so it is thicker and always has mesh.

The minimum thicknesses in the table come from our own practice with sand-cement mortar: any thinner and it cracks and comes away more often. We calculate the thickness from the highest point of the slab, not “with a margin”. A centimetre of this mortar weighs about 20 kg per m², and the floor slab has no need of extra centimetres across the whole apartment. The layer under a floating screed that stops footstep noise is described on the page about floor and slab soundproofing.

What we mix the mortar from and how we reinforce it

We make wet screed from a ready-made dry mix with its strength class on the bag, or mix Portland cement with washed sand on site, roughly 1:3 in our practice. We measure out the water according to the technical data sheet, not by eye. Extra water makes the job easier for the tradesman, but later it rises to the top as laitance and leaves a weak surface that dusts and cracks as it shrinks.

Semi-dry mix is pumped through a hose by a machine parked by the entrance. It contains little water, so it is compacted and finished with a power float, otherwise the top stays loose.

We add polypropylene fibre to almost every screed: in the first few days it protects the mortar from fine shrinkage cracks. Mesh is needed in a floating screed and in the layer over pipes. We raise it on spacers to the middle of the thickness, because mesh lying on the slab reinforces nothing.

Guide rails, perimeter strip and joints

We set the guide rails with a laser level at a spacing shorter than the two-metre straightedge, so that it always rests on two rails. Once the mortar has set, we pull out metal rails and fill the grooves: screed often cracks along the line of any metal left in it, and in humid air galvanised steel rusts over time. Before pouring, we stick perimeter strip around the walls, columns and pipes. The screed must not butt against the building's concrete: as it shrinks it cracks along the edge, and a floating screed also carries footsteps into the walls.

We pour each room in one go, because the joint between yesterday's and today's mortar remains a weak spot. In doorways we make a joint through the full thickness, otherwise the screed will crack exactly where the floor area suddenly narrows. In our practice, rooms larger than 30 m², long corridors and L-shaped rooms are divided into bays by joints that we cut to a third of the depth within the first 24 hours. Under tiles, the screed joints line up with the tile joints, and with underfloor heating they follow the boundaries of the heating loops.

The first week: screed is cured, not dried

Cement needs water to gain strength, so for the first few days we keep the mortar damp. We cover fresh screed with plastic sheeting, and if the surface turns pale, we dampen it. Draughts, sun and heaters draw water out of the top too early, and the surface develops a network of cracks or starts to dust.

We start drying after about a week, with ventilation and a dehumidifier. The screed must not be heated early with underfloor heating; how the system is first switched on is described on the page about water and electric underfloor heating.

How we sign off a screed

The tolerances in the table come from our practice for specific floor coverings, and we write the same figures into the estimate.

Areas that sound hollow, and cracks whose edges have shifted in height, are cut out and poured again. A through crack with no step is stitched with staples set in resin, and a dusty surface is strengthened with a deep-penetrating primer. If glue-down SPC vinyl needs a perfect surface, we add a thin self-levelling layer on top. When we doubt the meter, we tape down a one-metre square of plastic sheeting around its edges for 24 hours: condensation under it means it is too early to lay the floor covering.

What to do before screeding and what not to do after

By the time we pour, the water pipes and underfloor heating loops have been pressure-tested, the cables checked, and the runs photographed with measurements from the walls. In a walk-in shower without a tray, the screed sets the fall to the floor drain, so we work out its levels from the drain body. While the mortar is gaining strength, no pallets of tiles or barrels of water go on the floor. In a bathroom and on a balcony, liquid-applied waterproofing goes onto the dried screed, and the tiles go only on top of it.

How much floor screed costs in Batumi

Wet screed to guide rails costs from 40 to 66 ₾ per m²; this is labour only, for a layer up to 5 cm. The mix is priced separately: for a 5 cm layer the material comes to 30–42 ₾ per m², and the guide rails and perimeter strip are a line of their own, at 12–18 ₾ per linear metre. A level slab and large rooms are closer to the lower end of the range. A thick layer, floating screed with mesh, underfloor heating pipes and an apartment of small rooms with thresholds are closer to the upper end.

Removing old screed costs 69–90 ₾ per m², more than pouring a new one, so it is cheaper to prevent voids than to take the screed up later. The final cost is set after the site measurement and once the estimate is agreed, and the price of the stage is written into the contract.