Floor screed

Bonded floor screed

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

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.

Applications

Jobs that use Bonded screed

Screed mix ratio for a floorScreed

Same family

Other floor screed

Floating screed1 : 4Screed over insulation or a membrane (50 mm+).