Building Materials Guide
Cement, Mortar And Concrete: What’s The Difference?
They arrive on the same building sites and regularly get called the same thing. They are not. Here is what each material does and what you actually need to order.
Cement is a binding ingredient. Mortar is normally used between bricks and blocks. Concrete is used for stronger groundwork and structural applications. Asking for “a bag of concrete” when you mean cement is common — but it can produce a very different order.
The Simple Difference
Cement, mortar and concrete are closely related, but each one has a different role. The easiest way to understand them is to start with cement.
Cement
Cement is a fine binding powder. When mixed with water it forms a paste that hardens and binds other materials together.
Ingredient used to make mortar and concreteMortar
Mortar normally combines cement, building sand and water. It is workable enough to bed bricks and blocks and fill masonry joints.
Bricklaying, blockwork, pointing and repairsConcrete
Concrete combines cement, sand, coarse aggregate and water. The larger aggregate helps create a strong, solid finished material.
Foundations, bases, floors, paths and postsCement + building sand = mortar. Cement + sand + stone or ballast = concrete.
What Is Cement Actually Used For?
Cement is rarely the whole finished material. Its main job is to bind sand and aggregate together once water is added.
Different cement products and specialist premixed materials are made for different applications. Do not assume every bag is interchangeable, particularly where a drawing or specification names a product.
Cement is one ingredient in concrete. Calling them the same thing is like calling flour a cake. Useful ingredient, disappointing driveway.
What Is Mortar Used For?
Mortar is designed to be workable and spreadable. It creates the bed between bricks or blocks, helps keep masonry aligned and fills the joints between units.
Building sand is normally used because its fine texture helps produce a smoother, more workable mix. Sharp sand is coarser and is usually chosen for different applications.
Brick And Block Work
Mortar forms the bedding joints and helps distribute loads through masonry walls.
Pointing
Existing joints can be raked out and refilled where the original mortar has failed or weathered.
Small Repairs
Mortar is useful for replacing loose masonry and carrying out suitable localised repairs.
Not Every Wall Is The Same
Older buildings and specialist masonry may need a different mortar, including lime-based products. Check before using a strong modern cement mix.
Typical mortar order
Cement, building sand, clean water, mixer or mixing tray and the required bricklaying tools.
What Is Concrete Used For?
Concrete includes coarse aggregate, giving it the body and strength needed for groundwork and many structural applications.
For smaller general jobs, ballast provides a convenient combination of sand and stone that can be mixed with cement and water. Larger, structural or specified jobs may need ready-mixed concrete designed for a particular strength and application.
| Job | Likely Material | Important Check |
|---|---|---|
| Fence post | Postcrete or suitable concrete mix | Hole size, post depth and manufacturer instructions |
| Shed base | Concrete | Base thickness, preparation and drainage |
| Small footing | Specified concrete | Drawing, ground conditions and building-control requirements |
| Brick wall | Mortar | Brick type, exposure and suitable mortar specification |
| Pointing repair | Mortar | Compatibility with the existing masonry and mortar |
| Paving bed | Suitable bedding mortar | Paving manufacturer guidance and full-bed requirements |
Building Sand, Sharp Sand Or Ballast?
Choosing the correct aggregate matters just as much as choosing the cement.
Two piles of sand can look similar from the other side of the yard. The wrong one becomes much more obvious once you start mixing.
Should You Use A Premixed Product?
Premixed dry products can be useful for small jobs, repairs and work where convenience and consistency matter more than buying separate materials in bulk.
Mixing cement and aggregates separately is often more practical for larger jobs. It also gives greater control, but only when the correct specification and proportions are followed.
Premixed Bags
Useful for smaller quantities, local repairs and jobs where storing several separate materials is inconvenient.
Separate Materials
Often better suited to larger projects where cement, sand and aggregate will be used across several mixes.
Why The Mix Matters
A stronger mix is not automatically a better mix. Mortar that is too strong can be unsuitable for softer bricks or older masonry, while weak or badly measured concrete may not perform as intended.
Water content also matters. Adding extra water may make a mix easier to move around, but too much can affect its finished performance and increase shrinkage.
Follow the product instructions, drawings or specified mix. Do not rely on a shovel ratio remembered from a completely different job.
Mixing Cement In Warm Summer Weather
Warm, dry and windy conditions can make mortar and concrete lose moisture more quickly. Prepare the work area before mixing and avoid producing more material than can be placed and finished properly.
Keep unopened bags dry and shaded, dampen overly dry backgrounds where appropriate, and follow the product guidance for placing and curing. Never try to rescue material that has started setting by repeatedly adding more water.
Cement And Dust Safety
Wet cement can cause serious skin problems, including cement burns. Cement powder can also irritate the respiratory system.
Cutting, drilling or grinding hardened mortar and concrete can release harmful construction dust. Use suitable work methods, dust controls and personal protective equipment based on the task and risk assessment.
Wear suitable gloves and eye protection, avoid skin contact, control dust at source and follow the current HSE and product safety guidance.
What Should Be On The Order?
Once the required material is clear, check the full job rather than ordering the main bag and hoping the rest is already in the van.
Common Questions
Can Cement Be Used On Its Own?
Cement paste has limited specialist uses, but most common building jobs require it to be combined with sand or aggregate.
Is Mortar As Strong As Concrete?
They are designed for different jobs. Mortar prioritises masonry bedding and workability; concrete is used where a solid mass and greater compressive performance are needed.
Can I Use Concrete For Bricklaying?
No. Concrete contains coarse aggregate and is not intended to form normal brick or block joints.
How Much Do I Need?
Measure the job first. Allow for depth, waste and the exact product yield rather than estimating from the number of bags used last time.
Need Cement, Sand Or Ballast?
Canvey Supply stocks cement, building sand, sharp sand, ballast, postcrete, aggregates and general building materials for trade and DIY projects across Essex.
