Liquid screed questions

About 1 mm a day to 40 mm, then 2 days a mm. 50 mm: about 60 days.

Day 7 on calcium sulphate, day 14 on cement-based liquid screed at no more than 45°C.

After 24 to 48 hours.

Liquid screed is priced per m² for your floor: the area, the depth, calcium sulphate or cement-based, and how close the truck can get. Send the floor in and you get a written price.

Yes: cement-based liquid screed comes in 25 kg and 1,000 kg bags, and calcium sulphate in a bagged blend for smaller areas.

Wait at least 7 days after a flowing calcium sulphate or cementitious pour before running the manifold. Start the flow temperature at 20 to 25 degrees Celsius for three days, then step up by 5 degrees per day to the design maximum and hold for at least four days before stepping back down.

Most domestic floating floors need 25 to 35 mm of clear cover above the top of the heating pipe. Over a standard 16 mm pipe clipped to foil-faced insulation, that sets the total poured depth at 45 to 55 mm across the room.

Calcium sulphate screeds must be rotary sanded once firm to remove loose surface skin and open the pores so tile primer and adhesive bond properly. Certain low-skin cementitious flowing mixes only require light buffing to clean off site dust and plaster splashes.

A calcium sulphate screed must read 0.5 percent moisture or below on a carbide meter (0.3 percent if heated) or below 75 percent relative humidity under a sealed hygrometer hood before bonding timber, vinyl or microcement.

Insulation boards must sit flat on the subbase with no rocking, all board joints and staple penetrations must be taped, a continuous polythene slip membrane must be turned up the walls, and 8 to 10 mm perimeter foam strip must be sealed around every room edge and doorway.

Yes, provided the structure can carry the dead weight of roughly 90 to 110 kg per square metre at 45 to 50 mm depth and the subfloor is fully tanked with polythene so liquid cannot escape into joists or rooms below.