How to Use the Floor Screed Calculator
A floor screed is a layer of sand-cement mortar poured over a subfloor to create a smooth, level surface ready for tile, resilient flooring, or a finished slab. Getting the material quantity right before mixing or ordering ready-mix saves a mid-pour scramble. This calculator takes your floor area, screed thickness, and material density to give you the required volume, weight, and number of bags.
Screed thickness depends on the application: a bonded screed directly on a structural slab is typically 1 to 1.5 in thick, while a floating or unbonded screed placed over rigid insulation or radiant floor heating tubing usually needs 2 to 2.5 in to provide adequate cover over the tubing or mesh. Always check the minimum cover required by your flooring or radiant system manufacturer before finalizing the pour thickness.
Screed mixes are generally similar to or slightly denser than wall plaster, and this calculator defaults to 130 lb/cu ft as a representative value — switch to your product's technical data sheet figure for a more precise result. Larger pours are often placed with ready-mix concrete trucks rather than bagged material, so convert the volume result to cubic yards if you're ordering that way.
Frequently Asked Questions
A bonded sand-cement screed is typically 1 to 1.5 in thick, while an unbonded or floating screed over insulation or radiant heating tubing usually needs 2 to 2.5 in to provide adequate cover. Always follow the minimum cover thickness specified by the flooring or radiant heat system manufacturer.
Floor screed mixes are generally similar to or slightly denser than wall plaster because they're placed thicker and often need to embed tubing or mesh. A density of around 130 lb/cu ft is a common default, but check your specific product's technical data sheet for an exact figure.