Installing a Through Bolt Professionally
Here's a guide to help you install a through bolt, also commonly known as sleeve anchor bolts.
- Firstly, accurately mark the position for the through bolt on the concrete surface, making sure it is a fair distance from any edges.
- Use a drill bit the same size as the diameter of the through bolt. So, if you are installing a M12 through bolt, use a 12mm diameter carbide-tipped masonry drill bit which is suitable for concrete drilling.
- Set your hammer drill to hammer mode when drilling into concrete.
- Drill to a depth of three quarters of the length of your through bolt. For a 100mm anchor bolt, drill 75mm deep, this being the sum of the effective anchoring depth (50mm) and the maximum fixture thickness (25mm).
- To ensure an accurate depth of hole, mark your drill bit with tape at 75mm or use a depth stop.
- This next step is crucial for proper anchor performance, you must thoroughly clean the drilled hole
- Use a hand pump or compressed air to blow out loose debris, insert a nylon brush and scrub the sides of the hole, or blow out the hole again to remove any remaining dust.
- Screw the nut flush with the top of the sleeve anchor. Then place your fixture (up to 25mm thick) in position and insert the through bolt through the fixture and into the cleaned hole, until the washer and nut are tight against the fixture.
- Turn the nut by hand until it's finger-tight, then using a wrench tighten the nut to the manufacturer's recommended torque. If no specific torque is provided, a general rule is to tighten the nut 3 or 4 full turns past finger-tight.
- Ensure the bolt head is flush with or slightly protruding from the surface and test to make sure the fixture is securely fastened.
When installing several through bolts, maintain proper spacing between them as per the manufacturers guidelines.
Are Through Bolts Re-Usable?
Through bolts are generally not reusable so if removal is necessary, always use a new bolt for reinstallation.
By following these detailed steps, you can ensure a proper and secure installation of through bolts. However, and as always, consult the specific manufacturer's instructions, as there may be slight variations in recommended procedures or specifications between ETA option 1 through bolts, or different types of through bolts.