Days
Hours
Mins
Secs
Use our guide and calculator to work out cement and sand for your mortar mixes.
Article By: Tom Ayre
Last Update: July 2024
Calculating the correct mortar mix materials for your wall is important to ensure you build the wall correctly and keep costs economical.
The calculator we have built below helps save time with manual calculations. The calculator can:
Let’s get started.
Cement and mortar, though often used interchangeably, serve distinct purposes in construction. Cement is a fine powder made from marl, clay, and limestone, and is never used alone. It is a key ingredient in creating mortar (by mixing it with fine sand and water) and concrete (by adding aggregates like stones and gravel).
The ideal mortar mix ratio depends on the specific task. Consistency is crucial for any mortar mix. A good rule of thumb is that the mix should stay on a tilted trowel without sliding off. Different tasks may require varying amounts of sand for added stability, especially for load-bearing structures.
Inconsistent mortar strength can lead to serious issues, such as uneven drying times, resulting in cracks and potential wall collapses. There isn’t a universal mix ratio for all jobs, so the table below provides a general guide:
| Type of Job | Sand | Cement |
|---|---|---|
| Bricklaying | 4 | 1 |
| Pointing | 3 | 1 |
| External rendering | 3.5 | 2 |
| Floor screed | 4 | 1 |
| Chimneys | 5 | 1 |
| Paving joints | 3 | 1 |
| Retaining walls | 3 | 1 |
Always add water gradually to achieve the desired consistency and better control the mix.
Pointing requires specific considerations for mixing mortar. Key components include:
Sand and cement are the primary ingredients, with cement acting as the binder when water is added. For convenience, ready-mixed lime mortar can be a time-saving option.
Lime mortar is easier to work with due to its natural plasticising properties. It is particularly suitable for repointing older buildings as it is gentler on aged brickwork compared to chemical plasticisers.
Plasticisers are chemicals added to mortar to enhance its flexibility before setting, allowing for adjustments to uneven patches and holes. They also strengthen the mortar and improve its frost resistance.
Layering new mortar over old mortar is ineffective due to insufficient space for adhesion. For repairing crumbling mortar, scrape out the damaged areas carefully to avoid further instability or damage to the bricks. Once the defective mortar is removed, ensure the space is wide and deep enough to apply new mortar.
Weather conditions significantly impact mortar mixing and application:
For small repairs, hand mixing is feasible, but for larger projects, using a cement mixer ensures consistency and quality. Consider hiring a cement mixer for extensive work.
Materials Required:
92 Bellhouse Lane, Leigh-on-Sea, Southend-On-Sea, Essex, SS9 4PQ
76 Quill Street, Finsbury Park, London, N4 2AD
THS Concepts has a passionate team of surveyors and CAD draughtsman delivering detailed, thorough and accurate surveys and CAD drawings. We are far more than just a land and building surveying company.
