A guide to choosing the right type of cement: which one for structural work, bricklaying, rendering and home repairs?

When building, extending or repairing parts of a house, many people think all cement is the same. In fact, using the wrong type of cement is one of the main reasons houses develop cracks, spalling plaster, or at worst structural settlement. This article explains how each type of cement differs so you can use them correctly and get the best value.

1. Portland cement: the heart of structural work

This cement is designed specifically to take high compression and loads, and suits casting columns, beams, foundations or concrete slabs. Type 1 Portland cement is very strong and durable, but a word of caution: structural work that carries the building's load should always be calculated by an engineer and done by specialist tradespeople. Don't mix concrete for columns or beams yourself without the knowledge, because an inaccurate mix can affect the safety of the house.

2. Mixed cement: for general bricklaying and rendering

Mixed cement has stone dust or fine sand added during production, making it suitable for bricklaying, rendering walls and finishing work that doesn't carry much load. It's sticky, smooth, easy to render with and doesn't shrink as much as Portland cement, so it is excellent at reducing hairline cracks in walls.

3. Ready-mixed mortar and tile adhesive: convenient, quick and purpose-made

Ready-mixed mortars are very popular today, because you just add water in the ratio printed on the bag and use them straight away. They're clearly divided by job — tile adhesive, render for AAC blocks, or self-levelling floor screed — which makes work faster, quality easier to control and reduces dust on site.

Checklist for choosing the right cement for home jobs

• Columns, beams and foundations: use Type 1 Portland cement or order standard ready-mixed concrete
• Clay brick / concrete block laying: use mixed cement made specifically for bricklaying
• Rendering AAC block walls: use only ready-mixed render made for AAC blocks, for good adhesion
• Tiling: use cement-based tile adhesive suited to the size and type of tile (avoid laying tiles wet with ordinary cement)

Important caution: For work involving the main structure of the house, the electrical system or underground plumbing, call a specialist for safety. For small repairs, you can use ready-mixed mortar yourself, but don't forget to add Waterproofing product in places exposed to a lot of moisture, such as bathrooms or roof decks, to prevent the mortar going soft and flaking in the future.