Question 1

What is BS 8539 and why is it important for fixings?

Accepted Answer

BS 8539 is the British Standard for the selection and installation of post-installed anchors in concrete and masonry. It ensures that fixings are specified, installed and tested correctly to reduce the risk of failure. Following BS 8539 helps improve safety, ensures compliance, and provides clear accountability across a construction project.

Question 2

What is anchor pull testing and when is it required?

Accepted Answer

There are two main types of testing outlined in BS 8539 for concrete and masonry substrates. The most common type of test, “proof tests”, ensure anchors have been correctly installed. This type of test is conducted on a sample of live installed anchors and can help to identify any obvious installation errors. The second, and less common type of test is “suitability testing”, which is used on a sacrificial set of anchors to determine performance when manufacturer’s data is absent. Note however that where possible it is always better to select an anchor with ETA and complete a full design utilising the design method given in the anchor’s ETA.

Question 3

Do you offer on-site testing and technical support?

Accepted Answer

Yes. VJ Technology provides on-site pull testing, installation guidance and technical support across the UK. Our services are UKAS and CFA compliant, ensuring reliable and accurate testing results.

Question 4

What is DesignFiX software?

Accepted Answer

DesignFiX is VJ Technology’s advanced anchor and rebar design software. It enables engineers and contractors to design anchors according to EN 1992-4, generate detailed reports and design for long-term performance; up to a 100-year working life (on selected products).

Question 5

Who should use technical support services for fixings?

Accepted Answer

Technical support services are used by structural engineers, consultants, contractors, M&E specialists and specifiers. Anyone responsible for the design, installation or validation of fixings can benefit from expert guidance.

Question 6

What standards do your technical services comply with?

Accepted Answer

Our technical services align with key industry standards, including BS 8539 for anchor installation and relevant test standards for product testing. Our testing services are also UKAS and CFA compliant.

Question 7

Can you help review my project or specifications?

Accepted Answer

Yes. Our technical team can review drawings, specifications and load requirements to ensure the correct fixing solution is selected. We can also provide calculations, recommendations and compliance guidance.

Question 8

What types of projects do you support?

Accepted Answer

We support a wide range of projects, including commercial construction, infrastructure, façade systems, structural steel connections, temporary works and M&E installations.

Question 9

How do I request technical support?

Accepted Answer

You can contact our technical team by phone, email or by submitting your project details online. We can provide advice, testing services or a full technical review depending on your requirements.

Question 10

When should anchor pull testing be carried out?

Accepted Answer

Anchor pull testing should be carried out on a sample of installed anchors prior to loading, for safety-critical applications into concrete or masonry where the installation procedure is not supervised. If ETA anchors are installed by trained operatives working under supervision, then proof testing is not required. Anchor testing might also be required when manufacturer data is absent.

Question 11

What happens if fixings are not installed correctly?

Accepted Answer

Incorrectly installed fixings can lead to reduced load capacity, failure under stress, and serious safety risks. This can cause project delays due to rework or failed inspections.

Question 12

Who is responsible for anchor compliance on a construction project?

Accepted Answer

BS 8539 assigns responsibilities across multiple roles, including designers, specifiers, installers and testers. Each party must ensure that anchors are correctly selected, installed and procured as specified.

Question 13

What is proof testing for anchors?

Accepted Answer

Proof testing involves applying a controlled load to an installed anchor used in a safety-critical application in concrete or masonry. It is used to verify installation quality and identify any obvious installation flaws.

Question 14

What is the working life of an anchor?

Accepted Answer

The working life of an anchor defines how long the anchor may be used in service. Most anchor ETA’s provide an assumed working life of up to 50 years, if installed according to the specific criteria outlined in the ETA. Some anchor ETA’s can also support up to 100 years. Note however the ETA is not a guarantee of the working life.

Question 15

Do I need training for installing anchors?

Accepted Answer

Yes. BS 8539 recommends that installers are properly trained and competent. Training helps ensure fixings are installed correctly, reducing the risk of failure and improving compliance with industry standards.

Question 16

What factors affect anchor performance?

Accepted Answer

Anchor performance is influenced by several factors, including substrate type/strength, edge distance, spacing, installation method, and embedment depth.

Question 17

What is UKAS accreditation in anchor testing?

Accepted Answer

UKAS accreditation ensures that testing is carried out by a competent, independent body to recognised standards. It provides confidence that results are accurate, reliable and compliant with industry requirements.

Question 18

What is the difference between mechanical and chemical anchors?

Accepted Answer

Mechanical anchors use expansion or mechanical interlock to secure into the substrate, while chemical anchors use resin bonding. The best choice typically depends on load requirements, edge distance and required embedment depth.

Question 19

Why is edge distance important in anchor design?

Accepted Answer

Edge distance affects the load capacity and safety of an anchor. Installing anchors close to an edge reduces the cone resistance of the anchor under tension. Edge failure under shear loading must also be checked, which can greatly reduce the shear capacity of the anchor. Software such as DesignFiX makes it easy to check load combinations in cases where close edge distances are present. Note that the minimum edge distance given in the ETA must always be observed.

Question 20

How can I reduce risk when specifying fixings?

Accepted Answer

Risk can be reduced by using the latest design methods, selecting appropriate products e.g., anchors with ETA suitable for the base material on site, following BS 8539 guidance, and engaging with VJT technical support for design, and installation support.

Question 21

Accepted Answer

Frequently Asked Questions

Frequently Asked Questions