Efflorescence – Salt Removal – Spalling brick – Spalling Sandstone
Spalling Bricks & Sandstone Treatment.
Efflorescence Desalination.
Spalling Brickwork
As moisture evaporates from your bricks, the dissolved salts crystallise at the surface — the main evaporation point. These salt crystals grow and expand, leading to efflorescence, crumbling, and eventually spalling bricks if left untreated.
Before starting any salt removal treatment, we recommend conducting a salt percentage test. This involves collecting dust samples from your bricks and sending them to our lab to measure the salt concentration within the masonry. Testing before and after the Desalination process provides clear data on how much salt has been successfully extracted and how effective the treatment has been.
If your bricks or sandstone are crumbling, flaking, or showing visible spalling, contact us today. We’ll assess the condition of your masonry and determine whether our salt extraction process is the right solution for you.
What is Efflorescence & Spalling Bricks?
Efflorescence and spalling bricks occur when salts accumulate within the pores of masonry materials such as bricks, sandstone, or besser blocks.
Carried upward by capillary action, moisture transports these salts through the substrate until it reaches the evaporation point. As the water evaporates, the salts crystallise and expand — breaking down the internal bond of the masonry.
Over time, this process causes crumbling, flaking, and the visible surface decay known as spalling.
Masonry Desalination Systems
| Category | (Paper Mache) | BluVac (Vacuum Desalination) |
|---|---|---|
| Best use-case |  Delicate bricks, and large areas (200m²+) | Good for solid brick & block walls |
| Speed |  Slower process (1 month process) | Faster salt extraction (days not months) |
| Site visits / labour | Multiple site visits → higher labour cost | Fewer return visits |
| Environmental impact | High non-recycled paper usage | Environmentally friendly (Zero paper waste) |
| Finish / appearance on dark brick | Bonding agents can leave a white residue Paper fibres can lodge in pores | Zero fibre residue or white shadow. |
| Shelf life | Short shelf life once opened | No opened-product degradation issue |
| Very Delicate Bricks | Very gentle salt extraction process – Excellent for hand pressed bricks | Suction can pull the fines from very soft (hand pressed) bricks |
| Cleans Bricks | Only removes salts – no cleaning action | Removes salts and helps clean brick surfaces |
After more than 10 years of extracting salts from masonry across Sydney, we choose BlueVac in 9 out of 10 projects because it is
- Faster, cleaner, more cost-efficient.
- More environmentally friendly salt removal than paper mache methods.
- Does not use hundreds of kilos of virgin paper that typically doesn’t get recycled.
- Zero chance of leaving any white surface residue from chemical bonding agents.
- Proven and used across multiple government hertage buildings across Australia.
How Does Efflorescence & Spalling Bricks Happen?
Why Efflorescence & Spalling Bricks are Bad?
The ongoing formation of salt crystals within the pores of masonry gradually forces the material apart from the inside.
As these crystals expand, they break down the internal structure of the bricks, blocks, or stone — causing progressive deterioration over time. Eventually, the substrate can disintegrate completely, leaving only loose grains of sand.
This visible crumbling and flaking is known as brick spalling, a common result of long-term efflorescence damage in bricks, sandstone, and besser blocks.
With Salt Comes Damage
There are two main types of efflorescence:
Efflorescence in ceramic tiles — commonly seen on balconies and walkways.
Efflorescence in masonry — such as spalling and crumbling sandstone, bricks, or concrete.
We specialise in removing efflorescence from spalling sandstone and brickwork. (See the notes marked “***” at the bottom of this page if your efflorescence is coming from tile grout.)
Efflorescence occurs when salts migrate to the surface of masonry — brick, block, render, or concrete — and crystallise as the moisture evaporates. Rising Damp often accelerates this process, though efflorescence can also occur independently of it.
To stop flaking and spalling, the salts must be extracted from the masonry itself. There are several methods for salt extraction — steam jetting with vacuum recovery, chemical cleaning, and the desalination system.
We choose to use this desalination system because it delivers superior salt removal while remaining gentle on brick and sandstone surfaces. This low-impact method draws salts out effectively without damaging the structure.
We don’t use steam systems because, while they can dilute the salts, the pressure of the steam can also drive some salts deeper into the masonry — leaving hidden deposits that may resurface later.
Chemical salt removal methods often involve strong acids, which can permanently damage bricks, sandstone, and mortar. There’s also a risk of accidental spillage that can harm nearby surfaces. For these reasons, we believe Bluvac provides the safest and most reliable Rising Damp Solution for long-term results.
Things To Know About Spalling Bricks
- BluVac is specifically designed to extract salt from brickwork and sandstone to slow or stop spalling. It is not suitable for ceramic tiles.
- If your substrate is painted, the paint must be mechanically removed before BluVac. The product must contact the bare masonry surface to draw salts effectively.
- Applying a sealer to masonry does not prevent efflorescence — it can make the problem worse. Sealers trap salts beneath the surface, causing crystallisation and pressure buildup behind the sealed layer. Over time, the surface layer (held together by the sealer) can detach and peel off in sheets. **If your masonry has been sealed before, we can remove the sealer safely and non-invasively before salt treatment.
- Some salt types cannot be fully removed. In these cases, deterioration may continue even after extraction. We can perform salt testing to determine both the type and quantity of salts present before beginning treatment.
- In older Sydney properties, especially those with below-ground walls, leaking sewers or groundwater upslope can continually feed salts into the masonry. Even after successful extraction, new mineral-rich moisture can reintroduce salts during future rain events.
- Rising Damp is a major cause of salt damage and spalling. Sydney’s proximity to coastal salt air and groundwater often accelerates this process, making early Rising Damp Treatment critical.
- BlueVac is a gentle system that works using natural physics to draw salts out of the substrate. It’s ideal for fragile, crumbling, or heritage masonry.
The Paper Mache System
For very large surface areas, we may recommend temporarily “cocooning” the masonry in a specialised coating that draws salts out through capillary and osmotic action. Paper spraying can be effective on expansive jobs where scale justifies the process.
For typical residential applications, BluVac is usually more cost-effective. It allows controlled desalination without the need for large volumes of paper-based materials.
There are several methods used to treat efflorescence in masonry and stone. Pressure washing, acid washing, or sealing may appear to improve the surface temporarily, but they do not extract salts from within the substrate. In some cases, these approaches can drive salts deeper into the wall, only for them to resurface later and contribute to further spalling.
The paper mache system is well suited to very large projects, but it uses significant amounts of paper material, which may be a consideration for environmentally conscious clients. Bonding agents can also leave a light surface “shadow,” and paper fibres may occasionally remain visible in darker brickwork.
Both BluVac and paper mache are effective desalination systems. In most cases, we recommend BluVac because it is cleaner, more environmentally considerate, and avoids the surface residue issues sometimes associated with paper-based poultice systems.
***We do not treat efflorescence in tiles. If you have efflorescence on a balcony or external walkway, the issue usually comes from moisture entering the tile screed and carrying dissolved salts to the surface as it evaporates. This process can cause spalling, surface whitening, or surrounding bricks to begin crumbling over time. For lasting results, the affected area may need to be retiled.
That means removing the old tiles and screed, repairing or replacing the waterproofing membrane, and installing a new screed with an efflorescence-resistant additive before retiling. The lower membrane protects your structure; the upper layers manage vapour and water flow to reduce salt migration. Homes near the ocean experience faster salt accumulation due to airborne minerals. Rainwater dissolves surface salts, and when the sun heats the tiles, that moisture evaporates — leaving new salt crystals at the surface. Even with a membrane, high salt levels can still lead to visible efflorescence and occasional spalling bricks unless drainage and ventilation are improved.
Penetrating sealers and epoxy grouts can help, but they must be maintained. Transparent sealers degrade quickly in UV light and should be reapplied annually. If the screed is already damp, sealing the surface won’t help — trapped moisture will continue to push salts toward the surface and may cause scaling or surface failure.
We don’t repair balconies or external walkways, but we can advise on preventing spalling, efflorescence, and crumbling bricks through proper moisture management and salt control strategies.