1. Floor screeding

2. Understand applications and methods of laying sand and cement floor screeds

3. Aims: Objectives: Floor screeding To introduce floor screeding
To understand how to set out and lay floors to receive carpets, ceramic tiles and vinyl

4. What do you know? Floor screeding What is a bonded floor?
Introduction
What do you know?
What is a bonded floor?
What is a semi-dry mix?
How are screeds set out for a level floor?
How are screeds set out for a floor with falls?
What is curing?

5. Floor screeds Floor screeding
Plasterers have always laid floor screeds but large areas now tend to be carried out by companies that specialise in floor screeding.
Floor screeds are laid either level or to falls and can incorporate underfloor heating

6. Floor screeding Mixing proportions Mixing Ready-mixed screed Mixing
Mixes are usually
3 : 1 = 3 of coarse sharp sand to 1 of cement
4 : 1 = 4 of coarse sharp sand to 1 of cement
Mixing
Mixed to a semi-dry consistency (test: it should form a ball in your hand - too dry it will crumble, too much water and you hands will be wet)
Ready-mixed screed
Delivered to site, can have retarders added if doing large areas; quite often pumped into the building

7. Bonded floor screed Unbonded floor screed Monolithic
Floor screeding
Types of floor screeds
Bonded floor screed
The base is prepared and the screed laid on a pre-laid base
Unbonded floor screed
The floor screed is laid on a damp proof membrane (DPM)
Monolithic
The screed is laid no more than three hours after the concrete is laid
Floating floor screed
This is laid on rigid or semi-rigid insulation boards

8. Floor screeding
Floor screed setting out to level using dots or screed rule

9. Setting out falls by using square of datum line or packings of dots
Floor screeding
Falls used for shower or wet room
Setting out falls by using square of datum line or packings of dots

10. Floor screeding
Laying floor screed using battens

11. Floor screeding
Floor laid using dot and screed method

12. Curing and drying out Floor screeding
This means stopping the moisture in the screed to allow the cement to reach full strength. You can spray the floor lightly for around 7 days, cover the floor with plastic sheeting to retain the moisture in the screed, or you can spray a chemical on the floor which breaks down when curing is complete.

13. You should now have the knowledge to complete the following:
Floor screeding
Conclusion
You should now have the knowledge to complete the following:
What is a bonded floor?
What is a semi-dry mix?
How are screeds set out for a level floor?
How are screeds set out for a floor with falls?
What is curing?

14. THANK YOU