A mortar plasticiser is a liquid additive mixed into your cement and sand mix. It makes the mortar more workable and easier to spread, reduces the amount of water needed, and helps the finished mix resist frost during curing. For most bricklaying and pointing jobs in the UK, particularly in colder months, a plasticiser is well worth using as it improves both the working properties of the mix and its durability once set.
Building Chemicals for Mortar, Damp Proofing and Surface Cleaning
MacBlair stocks a focused range of building chemicals covering the four key areas most commonly needed on site or around the home: mortar additives and dyes, brick and patio cleaners, damp and waterproofing treatments, and fuels and oils. These are the products that often make the difference between a job that lasts and one that fails prematurely.
The additives and dyes range covers mortar plasticisers, frostproofers, accelerators and cement colourants. Plasticisers improve workability and reduce the water content of a mix, while frostproofers help mortar set properly during cold-weather laying — particularly useful given Northern Ireland's climate. Cement dyes let you match or contrast mortar colour to the surrounding brickwork.
Surface cleaning is covered by the brick and patio cleaners section. These products tackle mortar residue, efflorescence, algae, limescale and general grime from brickwork, concrete, paving and block surfaces. For moisture issues on walls or below-ground structures, the damp and waterproofing range includes integral waterproofers and SBR bonding admixtures that can be added directly to mortar, render or screed mixes. These are useful across a range of applications:
- Waterproofing basement walls, render coats and external pointing
- Treating damp-prone masonry before plastering or decorating
- Improving adhesion and flexibility in repair mortars
- Cleaning and restoring patio slabs, block paving and brick facades
The fuels and oils section is also stocked for those needing lubricants or fuel products alongside their build supplies. For related products used in finishing and bonding work, the adhesives range includes PVA, SBR bond and floor adhesives that complement many of the chemical applications above.
Chemical FAQ's
An integral waterproofer is added to mortar, render or screed to make the mix itself water-resistant. It reduces water penetration without forming a surface film. SBR (Styrene Butadiene Rubber) bond is a latex-based admixture that also waterproofs but additionally improves adhesion and flexibility in the mix. SBR is particularly useful where you need to bond new mortar to an existing surface, such as in repair work or waterproofing a basement wall.
Brick and patio cleaners are the most practical solution for mortar residue and efflorescence (the white salt deposits that appear on new brickwork). These are typically acid-based products that dissolve cement and lime stains. Always dilute as directed, wet the surface first, apply the cleaner, and rinse thoroughly. Avoid using them on polished stone or surfaces sensitive to acid. For algae and green staining on patios, a fungicidal or general-purpose patio cleaner is more appropriate.
Yes, cement dyes and colourants can be added to most standard mortar and concrete mixes. They are typically pigment-based powders or liquids that are mixed in at the batching stage. The final colour will depend on the ratio used and the colour of the cement and sand, so it is worth doing a small test mix first to check the dried result before committing to a full job. Consistent batching is important to avoid variation in colour across the finished work.
No. Brick acid and other acid-based cleaners should not be used on limestone, marble, polished concrete, or any surface sensitive to acid, as they can cause permanent damage or discolouration. They are generally suitable for clay brick, concrete block, and standard cement-based paving. Always check the product instructions for compatible surfaces, wear appropriate protective equipment including gloves and eye protection, and rinse the area thoroughly with clean water after use.