Types of Floor Screed

Bonded, unbonded and floating are the three types of floor screed.

Bonded Screed Bonded screed is a screed that gets laid directly on top of a pre-laid concrete surface. The face of the cement is flattened down with a rule but is left rough. This helps it to bond. Bonded screed should be between 25 mm and 40 mm thick. You will need to get rid of all the old droppings of plaster, dirt and dust and soak the concrete overnight before laying levelling screed. Before grouting, you should brush off any excess water. Grout is a mixture with a ratio of 1:1 sand/cement that is mixed in a bucket with water and is applied to the wet concrete and brushed in. To help bond the sand and cement to the base, PVA can be applied. Unbonded Screed Unbonded screed should be between 50 mm and 70 mm thick. The screed can be laid on to both new and old renovated concrete. The screed is not bonded to the concrete base. Cracks and holes should be repaired. So that the DPM (damp proof membrane) is not damaged, the cement should be clean and smooth so that is ready for DPM. This prevents damp coming through the floor. Cracks and holes should be repaired. Floating Screed Floating screed is used insulation boards that are either rigid or semi-rigid. The concrete should be level and smooth and all gaps between the boards and sub-base should be filled with either grout or floor screed. In domestic places, floating screed should be between 65 mm and 90 mm. For commercial places, the screed should be between 75 mm and 100 mm.