There are a lot of types of concrete anchors, and the reason is simple: they’re doing very different jobs. The anchor that holds a shelf bracket on a garage wall isn’t the one you’d use to bolt down a post base or a heavy piece of equipment. Picking the right one comes down to the load, the material you’re drilling into, and whether you’ll ever need to take it out again.
Key Takeaways
- Wedge anchors are a common choice for heavy loads in solid concrete.
- Sleeve anchors work in more materials, including block and brick.
- You drill a pilot hole with a masonry bit and drive the screw with a drill or impact driver, and the threads cut into the concrete.
- Adhesive anchors use epoxy or resin to glue a threaded rod or a piece of rebar into a drilled hole.
What Should You Figure Out First?
Three things. How heavy is the thing you’re attaching? Is the base solid poured concrete, hollow block, or brick? And will the load try to pull the anchor straight out, push on it sideways, or both?
The pull-out force is called tension, and the sideways force is called shear. Most anchors list a rating for each. For anything that holds people up, like a railing or a deck ledger, follow the plans and the local code, because those connections often call for specific hardware.
What Are the Main Types of Concrete Anchors?
Here’s a quick comparison.
| Anchor | How it holds | Common use |
|---|---|---|
| Wedge anchor | A clip expands as the nut is tightened | Heavy loads in solid concrete |
| Sleeve anchor | A sleeve expands along its length | Concrete, block and brick |
| Concrete screw | Threads cut into the concrete | Light to medium loads, removable |
| Drop-in anchor | Sits flush, takes a bolt | Overhead threaded rod |
| Adhesive anchor | Epoxy or resin bonds a rod in place | Heavy loads, near edges |
| Hammer-drive anchor | A pin expands the body | Quick, light fastening |
| Plastic plug | Expands as a screw goes in | Very light loads |
When Does a Wedge Anchor Make Sense?
Wedge anchors are a common choice for heavy loads in solid concrete. You drill the hole, tap the anchor in, and tighten the nut, and a clip near the bottom expands against the sides of the hole. People use them for post bases, machinery, and structural brackets.
They aren’t a good fit for hollow block or brick, since the clip needs solid material to grab. They’re also hard to get out once they’re set, so it pays to measure twice.
What About Sleeve Anchors?
Sleeve anchors work in more materials, including block and brick. The sleeve spreads its grip along a longer section of the hole, which is easier on softer masonry. They’re a reasonable choice for handrails, shelf brackets, and light framing on a block wall.
Why Are Concrete Screws So Popular?
Mostly because they’re fast. You drill a pilot hole with a masonry bit and drive the screw with a drill or impact driver, and the threads cut into the concrete. They can also come back out later, which a lot of people like.
They’re good for furring strips, electrical boxes, and light fixtures. The pilot hole has to be the size the maker lists, because a hole that’s even a little too big won’t hold well. Our guide to drill bits for wood, metal, and masonry covers how to choose the bit.
Where Do Adhesive Anchors Fit In?
Adhesive anchors use epoxy or resin to glue a threaded rod or a piece of rebar into a drilled hole. They don’t expand, so they put less stress on the concrete around them. That makes them useful near edges and for heavy loads. They need time to cure, and the cure time changes with temperature, so read the label before loading them.
How Do You Install Anchors So They Hold?
Most anchor failures come from the install, not the product. A hammer drill makes much cleaner holes in concrete and block than a regular drill. The hole should be the depth and diameter the maker lists. Blow or brush the dust out, since leftover dust can noticeably weaken the hold. Keep the distance the maker requires from edges and from other anchors, and tighten to the listed torque without overdoing it.
If you’re deciding which tool to buy, our comparison of an impact driver vs. a hammer drill may help.
Do Washers and Coatings Matter?
They do. A washer spreads the load under the nut and protects the surface, and our guide on when to use washers with bolts explains when you need one. For outdoor or coastal work, galvanized or stainless anchors hold up better against rust. Our article on stainless vs. galvanized fasteners covers that choice.
What Mistakes Cause Anchors to Fail?
A hole that’s too wide or too shallow is the most common one, since the anchor has less material to grip. Skipping the cleaning step is another. Setting anchors too close to an edge or to each other can crack the concrete, and overtightening can damage both the anchor and the concrete around it. Taking a little extra time on each of those steps, and reading the instructions on the package, prevents most of these problems.
Find Anchors and Masonry Tools in Los Angeles
Anawalt Lumber carries many types of concrete anchors, along with masonry bits, hammer drills, and fasteners, at our five Los Angeles area stores. Browse our hardware section or call our West LA store at (310) 478-0324. Family-owned since 1923, our team is happy to help you match the anchor to the job.
Frequently Asked Questions
Q: What is the strongest concrete anchor?
A: For heavy loads in solid concrete, wedge anchors and adhesive anchors are common strong choices. The right one depends on the load and the setting.
Q: Can I use wedge anchors in concrete block?
A: Wedge anchors are made for solid concrete. Sleeve anchors or anchors rated for block are usually a better fit.
Q: Can concrete screws be reused?
A: They can usually be removed, but reusing them may reduce their hold, so many makers suggest a new screw each time.
Q: Do I need a hammer drill for concrete anchors?
A: For most anchors in concrete or block, yes. It makes clean holes much faster.
Q: How far from the edge should an anchor go?
A: Check the maker’s edge distance guide. Anchors too close to an edge can crack the concrete.