Sulphate Attack

Sulphate Attack, sometimes spelt sulfate attack, is a chemical process that affects concrete structures, particularly those constructed with solid concrete floors or suspended timber floors with concrete subfloors.

This issue commonly arises in properties built during the 1950s, 1960s, and 1970s, when damp proof membranes (DPM) were not always installed beneath the slab. Sulphates present in the ground or hardcore beneath the structure can react with the concrete, causing it to expand, crack, and shift. This not only damages the concrete but can also affect other parts of the building, such as walls and any built off the concrete.

At Jaram Associates, we have years of experience in inspecting, diagnosing, and remediating properties impacted by sulphate attack.

Symptoms and Impact of Sulphate Attack

Sulphate attack can cause severe structural damage if left unchecked. Common symptoms of this issue include:

• Cracking and Expansion: The chemical reaction between sulphates and concrete results in the formation of expansive products, causing the concrete to crack and expand over time.
• Misalignment of Structural Components: As the concrete expands, it can push other structural components, such as walls, out of alignment, compromising the building's overall integrity.
• Damage to Flooring: This is particularly noticeable in solid concrete floors, including those that are overlaid with vinyl, as the expansion can lead to the deformation of the flooring.
• Wall Separation: Gaps may form between walls, especially around windows and doors, due to shifting foundations.

---

---

///////////////////////////

---

---

Sulphate Attack Surveys

At Jaram Associates, we offer a range of expert services designed to assess and remediate subsidence issues:

Visual Non-Invasive Survey

This initial survey is a non-invasive inspection that focuses on gathering visual information about the typical symptoms of sulphate attack. While it doesn't involve testing, it is an important first step in identifying visible damage, such as cracks and floor distortions.

Sulphate Attack Testing / Invasive Survey

For a more thorough assessment, we offer a comprehensive sulphate attack testing service. This involves taking concrete samples from the property and sending them to a laboratory for detailed analysis. We provide a full report, including the lab results. Testing options include:

• Total Sulphate Content: Measures the amount of sulphates present in the concrete.
• A precise method of identifying the crystalline structure of the compounds in the concrete.
• Petrographic Analysis:An in-depth analysis that examines the physical and mineralogical characteristics of the concrete.

Among these, X-ray Diffraction (XRD) is our recommended method, as it offers a balanced approach to detecting sulphate attack without excessive cost. This test provides valuable insights into the extent of the sulphate damage and helps guide remediation works..

---

Frequently Asked Questions about Sulphate Attack

What is sulphate attack?

Sulphate attack is a chemical reaction between soluble sulphates in the ground or hardcore and tricalcium aluminate in the cement constituent of concrete. This reaction forms expansive products called ettringite crystals, causing the concrete to crack, expand, and weaken over time. The reaction occurs when damp proof membranes were not used in construction.

Why is sulphate attack a concern?

Sulphate attack can significantly damage the integrity of a building's structure, causing cracks, misalignment and floor movement. It is concerned for older buildings constructed without modern damp proof membranes, where the soluble sulphates from the surrounding soil or hardcore can come into direct contact with the concrete.

Sulphate attack is typically not covered by buildings insurance, although there are exceptions. If you have any questions on the matter, get in touch with us and we would be happy to help.

How do I know if my property is affected by a sulphate attack?

Signs of sulphate attack include visible cracking in the concrete, especially floors and movement of the brickwork below DPC. If you suspect your property is affected, it's advisable to arrange a professional survey to accurately assess the situation.

How do I know if my property is affected by a sulphate attack?

Signs of sulphate attack include visible cracking in the concrete, especially floors and movement of the brickwork below DPC. If you suspect your property is affected, it's advisable to arrange a professional survey to accurately assess the situation.

Can sulphate attack be repaired?

Yes, sulphate attack can be mitigated, but the process is often extensive and involves excavating the floors of the property. In many cases, kitchens and bathrooms built over these floors will need to be removed as part of the remediation work.

Why Choose Jaram Associates for Sulphate Attack Assessments?

At Jaram Associates, we specialise in diagnosing and remediating sulphate attacks in buildings. With over 30 years of experience in the construction and surveying industry, we utilise a range of advanced diagnostic tools to provide precise assessments.

If you suspect sulphate attack is affecting your property, or you simply want to learn more about our sulphate attack surveys, contact us today for expert advice and assistance.