Anchor testing for contractors

1. Get the test plan from the specifier: what the tests are for, preliminary or proof, the load, and how many.
2. Map the discrete areas. Each trade's anchors are usually their own area: a different anchor, base material, weather exposure (another elevation, for example) or installation team each starts a new one, with at least 3 tests in each.
3. Book preliminary tests early. Where the base material has no maker's data, typically masonry, at least 5 anchors (more if they are tested to failure) are installed just for the test, and the result decides the anchor or its load before installation starts.
4. Let bonded anchors cure. Resin anchors are tested only after at least the maker's recommended curing time.
5. Test while anchors can be reached. Our advice: schedule proof tests before fixtures, ceilings or cladding hide them, and choose the anchors at random.
6. Invite a witness from the client or the engineer.
7. Collect the reports and pass them to whoever asked for the tests.

Put it in writing, in four parts. The job: the project, where the anchors are (with a drawing reference) and who the tester meets on site. The anchor: make, type and size, the drill diameter, hole depth and torque, what the connection holds, and whether the anchors are in already or the tester installs them. The test: allowable load or proof, tension or shear, the characteristic action and factor and so the test load, and how many anchors there are and how many to test. The site: access such as work at height or a confined space, whether fixtures can come off, and the base material's minimum strength and thickness. If the base material on the day isn't as specified, the tester refers back to you before testing. Parts 1 to 4 of our anchor test report template take most of these details.

The CDM Regulations 2015 say any temporary support or structure must be "of such design and installed and maintained so as to withstand any foreseeable loads which may be imposed on it", and they count scaffolds, formwork and falsework as structures. HSE says appointing a temporary works coordinator is an effective way to manage this, though the title isn't a legal requirement, and points to BS 5975-1:2024 for the procedures. Our advice: where temporary works rely on anchors, such as props fixed to a slab or scaffold ties, the coordinator checks that the designer's test requirement is met and the results are back before the works are loaded.

No failures are expected where anchors are selected and installed as BS 8539 and the maker say. One failure in an area: investigate, and raise that area's sample to 5%, with at least 6 tests. More than one: test every anchor in the area, find the reasons and reconsider the specification. Tell the specifier and the installer either way. A replacement goes in a new position chosen by the specifier, unless a specialist or the anchor maker advises re-using the hole.

Each test in the Staht Connect app carries the peak load, target load, pass or fail and the time, with photos and a map pin. On the dashboard at app.staht.com, tests can be filtered by date, location, client, project or team member, and turned into a report in one click.

An M&E contractor's team has fixed 480 anchors into concrete soffits: one discrete area.

1. Sample: 2.5% of 480 = 12 proof tests.
2. Load: with a proof factor of 1.5 and N_Ek = 2.0 kN, each is loaded to 3.0 kN, provided that's no more than 1.5 times the maker's recommended load.
3. One fails. The team investigates, and the area's sample rises to 5%: 24 tests, which is more than the minimum of 6.
4. A second fails. Every anchor in the area is tested, the reasons are found, and the specifier reconsiders the specification.
5. Reports: each test is reported to the person who asked for it, and the specifier and installer are told.

• Construction: the rules, standards and kit
• BS 8539 proof testing and preliminary tests
• Anchor test report template: free fillable PDF
• Anchors in concrete and masonry: the kit