Question 1

What does cement plasticiser do?

Accepted Answer

Cement plasticiser significantly enhances the workability of fresh cement and concrete mixes without the need to add extra water, which helps maintain the overall strength of the final product. By improving flowability, plasticiser makes the mix easier to handle, spread, and shape—reducing labour time and effort during construction or repair work. It also improves the bond of the cement or concrete to surfaces, ensuring a more secure and durable adhesion in applications such as bricklaying, rendering, or plastering.

In larger-scale projects, plasticiser greatly facilitates the pumping and transportation of concrete, enabling it to be delivered smoothly and efficiently over longer distances. This reduces the risk of blockages and helps maintain a consistent mix quality on-site, especially in challenging or large-volume pours. Overall, cement plasticiser is a vital additive for achieving high-quality work with less effort and better results.

Question 2

What is mortar plasticiser?

Accepted Answer

Mortar plasticiser is a specially formulated additive designed to improve the workability and cohesion of mortar mixes. Similar to cement plasticisers, these products make the mortar smoother and easier to spread, even in colder or wetter conditions. By enhancing plasticity, mortar plasticisers help achieve a more consistent and uniform texture, which reduces the risk of cracking and improves the overall durability of the finished joint. This results in neater pointing, better surface bonding, and longer-lasting support for bricks, blocks, or stonework. Whether used in bricklaying, pointing, or rendering, mortar plasticisers are essential for ensuring a high-quality, professional finish with less effort.

Question 3

How much plasticiser should I use in a mortar mix?

Accepted Answer

The standard dosage of plasticiser is typically around 75ml for every 25kg of cement. However, it’s essential to follow the manufacturer’s specific instructions, as recommended quantities can vary depending on the product and application. Accurate dosing ensures optimal workability and prevents issues such as over-porosity or reduced strength. Always read the technical datasheet provided by the supplier and conduct a small trial mix if unsure, to determine the best amount for your project. Proper application of plasticiser results in a smoother, more cohesive mortar that bonds well, reduces cracking, and enhances overall durability.

Cement and mortar plasticisers

Sika SikaMix Plus Mortar Plasticiser 5L

Bostik Cementone Mortar Plasticiser 5ltr

Bostik Cementone Mortar Plasticiser 25ltr

Bostik Cementone Concentrated Mortar Plasticiser, 1 L

Sika Rendermix Water Resisting Plasticiser 5L Red

Sika Sikamix Plus Mortar Plasticiser 25L Brown

Sika MaxMix Plasticiser Brown - 1L

Everbuild Opti-Mix Super Concentrate Mortar Plasticiser 1L

Fosroc Cebex 100 227g (Conbex)

Bostik Cementone Freeflo Waterproofer, Plasticiser & Retarder 25 Litre

Sika Concentrated mortar plasticiser

Bond It Integral Water Resistant Plasticiser - 5L

Bond It Liquid Mortar Plasticiser - 5L