How to Mix Mortar Step by Step

Mortar is the basic mix behind every building project: it bonds bricks and stones together, holds building elements in place and is used for rendering walls. Mixing it properly – with the correct ratio and the right consistency – is what decides whether a job lasts or ends up cracking. We'll explain step by step how to mix mortar like a pro.

What is mortar and what is it used for?

Mortar is a mix of cement, sand and water (sometimes with lime). It is used to build walls from bricks or stones, to render and finish walls, to bed building elements and to level surfaces. The ratio is adjusted depending on the use: more cement for greater strength, a little lime to make it easier to work with.

Materials and tools

Materials:

• Grey cement (Portland type CEM II)
• Washed sand (river or crushed sand), clean and free of clay
• Clean water
• Optional: hydrated lime, for a more workable cement-lime mortar

Tools:

• A cement mixer or, for small amounts, a mortar board or mortar tub
• Shovel and bricklayer's trowel
• A bucket for measuring out (the key to getting the ratio exactly right)
• Hose or bucket of water

How to mix mortar step by step

1. Choose the ratio

   For brickwork, a common mix is 1:4 (1 part cement to 4 parts sand). For rendering or greater strength, use 1:3. If you want it to be more workable, add one part lime (cement-lime mortar 1:1:6).

2. Measure out with the same bucket

   Always measure with the same container to keep the ratio exact: for example, 1 bucket of cement to every 4 buckets of sand.

3. Mix it dry

   Add the cement and sand together and mix them both before adding the water, until the colour is even and free of streaks. If you're using a cement mixer, let it run for a few minutes.

4. Add the water gradually

   Never all at once. Add the water bit by bit as you mix, until you get close to the consistency you want: it is always easier to add more than to take some away.

5. Find the right plasticity

   The mortar is ready when it is nicely workable but doesn't run: when you pick some up with the trowel and turn it over, the mortar should hold without falling off and without crumbling.

6. Mix it through again before use

   Let it rest for a few minutes and mix it through again. This way the moisture spreads evenly and the mortar comes out nice and even.

7. Use it in good time

   You have about 1.5–2 hours before it starts to set. Don't add any more water once it has begun to set: it would lose strength.

Pro tips

• Only mix as much mortar as you'll use in about an hour.
• Use clean sand: clay or dirt will cause cracking.
• On hot days, work in the shade and dampen the surface so it doesn't dry out too quickly.
• For laying tiles, tile adhesive is now used rather than traditional mortar: it is more convenient and more reliable.

Mixing mortar properly is the foundation of every solid building project. And if your project needs expert hands – a wall, some rendering or a complete refurbishment – you can request a no-obligation quote in Calpe and the Marina Alta, or take a look at our building and renovation services.