Cement Small Bags

Mixed with ballast at around 1:5, a 25kg bag makes roughly 0.08 to 0.1m³ of concrete, so plan on 10 to 13 bags per cubic metre. As 1:4 mortar, one bag lays around 100 to 150 bricks.

For bricklaying mortar, use 1 part cement to 4 or 5 parts washed building sand, roughly 110 to 140kg per bag. For concrete, use 1 part cement of 5 to 6 parts 20mm all-in ballast, which already contains sand. Paving and screed mixes use sharp sand 1:3 to 1:6.

Cement is the powder that binds the other materials together. Mortar is cement, sand and water, used to lay bricks and bed paving. Concrete adds coarse aggregate such as gravel, which makes it strong enough for bases, footings, paths and posts.

GP cement, also known as OPC or “dust”, is suited to most everyday building work, including concrete, mortar, render and screed. Typical jobs include laying bricks and blocks and bedding patio slabs, pouring shed bases and general repairs.

White Portland Cement works like grey cement but has a high degree of light reflection. It is used where appearance matters, such as white render, decorative concrete, pale pointing and coloured mixes. A truly white finish needs white or light-coloured sand and stone, as darker aggregates dull the colour.

Yes. GP cement mixed with 20mm all-in ballast at around 1:5 or 1:6 makes a strong post mix. Set each post about a quarter of its length into the ground, for example 600mm for a 3.4m post. Slope the top of the concrete so water runs off. For a faster job, Poscrete is a quick-setting dry blend made for fence and gate posts, with no mixing needed.

Most bags carry a use-by-date, typically around three months from packing, and cement weakens as it absorbs moisture. Store bags off the ground on a pallet in a dry, covered space, away from damp walls and floors. Reseal part-used bags. Discard any cement with hard lumps that don’t crumble between your fingers.

Bagged cement suits small jobs such as posts, pointing and repairs. For around 1m³ or more, ready-mixed concrete saves time and gives a more consistent result: hand-mixing 1m³ takes around three hours and more than 20 wheelbarrow movements. Mick George Mini Mix delivers loads from 1m³ to 4m³ in smaller mixers, with bookings up to seven days ahead.