A rich 1:3 sand-cement screed used at 25-40 mm where it is bonded to the base slab. A semi-dry mix, compacted and trowelled level.
Mix ratio
1 : 3
Cement : Sharp sand
Proportions & strength
Bonded floor screed: proportions by volume, typical compressive strength and use.
Designation
Bonded screed
Ratio (by volume)
1 : 3
Cement
1 part
Sharp sand
3 parts
Typical compressive strength
3,625 psi · 25 MPa
Typical use
Thin (25-40 mm) screed bonded to a slab.
Planning reference. Strengths are typical values for a well-made mix at 28 days, not a guaranteed design strength. Structural work must follow your local building code and a qualified engineer's mix design.
Where Bonded screed is used
A rich 1:3 sand-cement screed used at 25-40 mm where it is bonded to the base slab. A semi-dry mix, compacted and trowelled level.
Screed is a semi-dry mix - just damp enough to hold together when squeezed. Too much water and it shrinks, curls and cracks as it dries.
Need quantities? The volume calculators give the cubic yards, cubic metres and bag counts for the pour this mix goes into.