Plaster and screed

Cement and sand for plastering walls or laying a floor screed. Enter the area and thickness, get the mortar volume, bags and sand in m³ and wheelbarrows.

✓ Free, no sign-up ✓ Works on your phone, standing at the problem ✓ The formula and the assumptions are always shown

IT CIVILS  ·  IT ADMIN BUSTER
1 Enter the job

Plaster and screed

Worked out at itcivils.com/free/calculators/  ·  Free construction calculators for site teams.
Check every quantity against your own specification and your supplier's own figures before ordering.

A worked example

This is the job the page opens with, already worked out. Change any figure above and the answer changes with it.

The job

What are you doing
Plaster on walls
Length
10 m
Height or width
3 m
How many surfaces
1
Openings to deduct
0 m²
Thickness
15 mm
Waste
10 %
Mix
1:5, general walling

The answer

3.091bags  ·  Cement, 50 kg bags

Net area
30 m²
Mortar at 15 mm
0.45 m³
With 10% waste
0.495 m³
Cement by mass
154.5 kg
Sand
0.536 m³
Sand, wheelbarrows
8.25

The working

30 m² × 15 mm = 0.45 m³, plus 10% = 0.495 m³.
× 1.3 for the dry volume, split 1:5.

What it assumes

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Every one has its own page, so you can bookmark the one you use most.

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On the job

2 Stay in the loop

Get the next tool when it lands

New tools get built when the admin gets annoying enough. Leave your email and you will hear when the next one lands. What you do on site is what decides what gets built, so it is worth saying.

Why these are free, and what they assume

These come from ten years on site: first in contracting on production and civil works, then in consulting doing construction monitoring for consultants appointed by the City of Cape Town. Working a quantity out twice, because the first answer was on a piece of board that blew away, is a thing that happens to everybody.

Every calculator shows the formula it used and the assumptions it made, because a number with no working behind it is worth nothing on site. Where a figure varies by material or supplier, it is an input you can change rather than something hidden. Check the answers against your own specification and your supplier's own figures before you order. These help you work faster, they do not replace your own judgement.

If they save you time, the paid IT Admin Buster packs cover the admin side: progress report templates, daily diaries, inspection checklists and the wording banks that go with them.