Why Do Bricks Turn White on New Builds

The white staining that often appears on bricks of new build homes is known as efflorescence. It is a common and natural phenomenon that affects many types of masonry in the early stages after construction. While it can look unsightly, especially on dark-coloured bricks or modern façades, efflorescence is generally harmless and can be treated or prevented with the right approach.

What Is Efflorescence

Efflorescence is the result of water-soluble salts within the brickwork or mortar being drawn to the surface by moisture. When water from rain, dew or construction processes enters the brickwork and then evaporates, it leaves behind a powdery white residue. These salts are naturally present in clay bricks, cement, sand and even some building aggregates, and become more visible once the water evaporates and the surface dries.

This process is particularly noticeable on new build homes because they contain a lot of moisture from wet trades such as bricklaying, plastering and screeding. As the building begins to dry out, these salts are drawn to the surface, creating the characteristic white staining.

Why It Happens More on New Builds

New build homes are more prone to efflorescence simply because of how recently they have been constructed. During the build process, bricks, blocks and mortar absorb water. Once the structure is completed and begins to dry, especially during the first few months, moisture starts moving through the masonry and evaporates at the surface. This is the phase when efflorescence is most likely to occur.

Additionally, if construction takes place in wet or cold weather, or if materials are not protected from rain during delivery and storage, they may absorb more water, increasing the chance of white staining appearing.

Is Efflorescence a Structural Problem

In most cases, efflorescence is not a structural concern. It is a surface-level issue and does not affect the strength or durability of the bricks or mortar. It usually disappears over time as the building continues to dry out. However, persistent or heavy staining may indicate ongoing moisture ingress, which could warrant further inspection to rule out leaks or drainage issues.

If the staining is accompanied by crumbling mortar, flaking brick surfaces or damp interiors, a more serious problem such as water penetration or poor construction detailing may be present and should be investigated by a qualified professional.

How to Remove White Stains on Brickwork

Most efflorescence can be removed using a stiff dry brush. It is important not to use water during the cleaning process, as this can dissolve the salts and draw them back into the brickwork, only for them to reappear again once the surface dries. In stubborn cases, proprietary efflorescence cleaners are available, but these should be used carefully and in accordance with manufacturer instructions.

Allowing natural weathering, especially in dry conditions, can also help reduce and eventually eliminate the staining over time. In general, efflorescence is a temporary issue and will fade as the building reaches its moisture equilibrium.

Can Efflorescence Be Prevented

While it cannot always be completely avoided, there are steps that builders and developers can take to minimise the likelihood of efflorescence. These include covering bricks and sand on site to prevent saturation from rain, using low-salt mortar mixes, installing damp proof courses correctly, and allowing walls to dry gradually.

Proper site drainage and water management also help prevent long-term issues by reducing the exposure of masonry to ongoing moisture.

Conclusion

Bricks turn white on new builds due to efflorescence, a harmless but unsightly deposit of salts brought to the surface by moisture as the building dries out. It is a common issue seen in the first months after construction and typically disappears over time or can be cleaned with minimal effort. While usually not a cause for concern, persistent white staining could signal an underlying damp issue and should be monitored if it continues for an extended period.