The Different Types of Wall Anchors
Ever needed to fasten items to concrete or brick walls? Say, a handrail, a TV wall bracket, or even industrial shelving for the workshop. Choosing the type of fastener, or wall anchor you need, doesn’t have to be time-consuming or difficult. There are a few things to go by, to keep any fixture or addition to walls, as safe as houses.
First, the obvious one. The size and weight of anything that you intend to attach to a wall. For smaller and lighter items, like sockets and conduit saddles, you can use just a single light-duty anchor in thinner diameters and shorter lengths. Like a nylon anchor for instance. Heavier objects and those that need more support, like floating stairs, or machinery, require something with a little more holding strength. Maybe a sleeve or wedge anchor. Choosing the right type of masonry wall anchor begins with the wall fixture. In this sense, there are light, medium and heavy-duty wall anchors.
Next is the material of the wall you’ll be anchoring into. Masonry walls can consist of brick, stone, block or concrete. Concrete and stone will be used more in the foundations, floors or ceilings and brick and block in walls. But here too, some variations affect your choice of an anchor. There are hollow and solid bricks, coming in both a hard and soft variety. The same can be said for concrete blocks. There is hollow and solid concrete block and different anchors suitable for each type. Wall thickness and consistency are determining factors here.
Where the anchor will be installed also narrows your choices. Some will be intended for use on exterior walls, and as such, need to be corrosion, heat and chemical resistant. The choice of materials, like stainless steel, as well as coatings, dictate where anchors can be used. For interior walls, zinc or zinc-coated anchors are a more affordable and suitable option.
Lastly, consider whether the fixture will be permanent or needs to be removed some time in the future. Anchors that are easy to install won’t necessarily mean that they are easy to remove, without damage to the wall that is. Most removed anchors can also be reused without any issues.
Types of Masonry Wall Anchors
Masonry wall anchors encompass dozens of different types (some going by various names), used for different applications, environments, and different types of walls. They are sold in varying lengths and diameters, and made of different materials. These are some of the most commonly used:
These are used for a range of different applications, from light to heavy-duty, and often the preferred choice for solid concrete. They consist of two pre-assembled pieces, with a wedge that expands into the concrete when the anchor is tightened. Zinc-plated variants are good for indoors and light-duty use, whereas stainless steel and hot-dipped wedge anchors, are better suited for more demanding settings. Different sizes and diameters will determine overall holding strength.
This masonry anchor has a metal sleeve sitting over a threaded bolt. Like wedge anchors, this is another type of expansion anchor. The sleeve expands into the wall as the nut, fixed along the bolt, is tightened. Sleeve anchors are ideal for medium loads, like handrails, shelves and door frames. They too are available in a range of materials and sizes, with larger carbon steel sleeve anchors having the highest holding strength.
Self-tapping concrete screws are ideal for cracked concrete, where the use of expansion wedge or sleeve anchors is unsuitable. Since they don’t expand on installation, they can also be used at closer distances. Concrete screws have a specially-designed thread along the entire length that effectively locks into the wall. The benefit of these concrete anchors is the variety of different head styles which allows for a flush finish against the wall. They are extensively used in light-duty overhead applications, like light fixtures.
Soft Shield Anchors
These were widely used before nylon anchors, but still found in several light-duty applications in brick and hollow concrete blocks. They are used in conjunction with screws, which fit inside and when turned expand the soft metal shield into the wall. A benefit is that they are removable.
Another masonry wall anchor used in light-duty work, especially with wooden fixtures, is the hammer-drive (hammer set) anchor. It consists of two parts, a zinc pin inside a steel body. The anchor is installed by moderately hitting it into the masonry wall with a hammer or mallet. Once installed it offers a tight fit. A downside is that it can’t be removed without damage to the pin, wall and fixture.
These are similar to hammer-driven anchors, but consist of a nylon outer plug that expands into the masonry when the screw or stud inside is tapped in. They too are useful for light-duty work, like electrical fittings, and can be removed.
Chemical anchors are the go-to fastener for heavy-duty anchoring into a hollow or solid concrete block. They consist of a stud and adhesive, that expands on curing, filling any cracks or imperfections in the wall. As such, they have extremely high holding strength, even exceeding traditional wedge anchors. Chemical anchors are also suitable for fixtures placed along edges and corners, where an expansion anchor might cause cracking. Typical uses include steel and wood fixtures; like industrial shelving, patios, porches and more.