You may have wondered whether it’s always necessary to drill a hole into concrete to attach something. Drilling a hole is often the first option that comes to mind, but is it the best? How do you attach something to concrete without drilling, are there others?
There are many tried and tested methods for attaching something to concrete without drilling, including masonry nails, and powder-actuated fasteners, as well as various types of adhesives. The attachment method will depend on the size, shape, and weight of the item you’re attempting to attach.
This article will discuss a range of alternatives to drilling for successfully attaching items of varying weights, shapes, sizes, and compositions to concrete.
Common Ways to Attach Something to Concrete
A few methods method will probably come to mind for anyone who has hanged a picture, like using hard wall hangers, masonry nails, or adhesive wall hooks. However, there are also more powerful options like power-actuated fasteners.
A simple hardware hanger will have several pins built into a plastic hook that you can drive into a wall. These usually are intended for wood or drywall, but some are substantial enough to hammer into a pitted concrete wall. Most are not well-suited to anything over 20 pounds, though.
Masonry nails are an elementary option made of steel that you hammer into the concrete. They are quick and easy to do, allowing you to hang pictures without any fuss, although some consider them to be a sloppy fix.
However, the object you’re hanging will usually obscure the nail from view, so this is not a significant concern for most people.
They’re primarily used to fasten wooden furring strips or floor panels to concrete. You can also purchase wedge-shaped stub masonry nails, but they’re designed for use with form ties.
Depending on the grade of your concrete, a single masonry nail can usually support around 20 pounds.
Adhesive Wall Hooks
Adhesive wall hooks require a clean, smooth surface. Once you peel the paper backing off, apply pressure against the concrete for 20 to 30 seconds to secure the bond. The maximum weight supported by adhesive wall hooks is only eight pounds.
Both adhesive wall hooks and hardware hangers can be useful for placing hooks to hang coats at doorways or rows of keys for easy access.
Powder-actuated fasteners use a powder charge to fire nails or pins into the concrete. These use gunpowder and can be dangerous. You should only use them on poured concrete and wear the proper eye and ear protection during use (source).
Powder-actuated fasteners and concrete nailguns are frequently used to fastened wooden frames to concrete slabs. Some of the fasteners used contain plastic flutes on the head to prevent them from backing out once they’re in place.
Attachments and Concrete Types
Simply put, concrete is a mixture of cement and aggregate that obtains its strength from the addition of water and the way it is cured. Manufacturers produce different concrete products with various types of aggregate, the amount of water required, and curing times.
These variations will also influence the mechanism needed to hang an attachment without drilling.
For example, an ultra-lightweight concrete contains aggregates such as perlite or vermiculite. It is mainly used for insulation and is soft enough to saw and drive nails into it. Aggregates consisting of crushed limestone or bricks, expanded slate, or shale produce lightweight concrete.
Both concrete products are less dense than those using hard aggregates, which makes it easier to apply an attachment mechanism to them.
Regular and heavyweight concrete is used for construction projects, where high density and durability is required. Achieving this density and durability necessitates the use of a coarser aggregate, like stone or gravel, with the reinforcement of steel rebar (source).
Constructed in 1930, the inspirational Empire State Building in New York demonstrates the durability and longevity of concrete. The Burj Khalifa in Dubai was completed in 2004, reaching 830 meters in height, and this building demonstrates the advancements made in heavyweight concrete strength.
Consider carefully the attachment method you use for the weight class of your concrete. Whether it’s simply a glass mirror, a picture, wood, plastic, metal, tiles, or concrete to concrete, each may need a different application.
For some applications, like powder-acuated fasteners, you need to be especially careful that your concrete is neither too soft nor too brittle; otherwise, you will create cracks in the concrete that may worsen over time.
Several brands like Quikrete, Loctite, and Liquid Nails claim that their product is the “best” adhesive for concrete, whether it’s high bond strength, rapid setting, high “grab” factor, and versatility for adherence to concrete. However, concrete does not have a great intrinsic bonding ability due to its makeup.
Despite this, the application of adhesives to hang attachments to concrete is widespread. The types are designed to suit different applications, such as pressure adhesives for light objects, acrylic, spray, and resins for a multitude of uses and epoxy and polyurethane adhesives.
A good adhesive bond requires proper wetting properties, meaning the adhesive should not merely bead on the surface but be capable of spreading along the surface. The ability to flow into the pores of the concrete is necessary to create mechanical locking to the surface (source).
The surface layer of the concrete must be clean and have a solid surface. Loose particles in concrete will compromise the bond. The same principle applies to the long-term quality of the concrete to sustain the bond over time.
Adhesive Bonding of Wood and Concrete
You can attach both hardwood and softwood successfully to concrete by using a flexible adhesive. This category of adhesive caters to the difference in thermal expansion coefficients of the wood and the concrete, thereby allowing for small movements within the wood.
Normally, wood can be attached without initial support but, should it begin to slide, temporary support is advised. Quikrete, for example, sells a polymer construction adhesive that is permanently flexible for use on wood, stone, and concrete surfaces (source).
Liquid Nails produces a construction adhesive known as Fuze IT All Surface Adhesive that also establishes a firm bond with the metal.
Adhesive Bonding of Metal and Concrete
An epoxy adhesive consisting of a two-step process of epoxy resin and hardener for both interior & exterior applications is best for attaching metal to concrete. Giving the metal a rough surface by scratching it beforehand will improve its adherence to the adhesive.
Attaching Stone, Tile, Brick, or Masonry to Concrete
A polyurethane construction adhesive generally produces the best bonding for stone, tile, or brick to concrete. This is a commonly-used method for the hanging of items like granite, ceramic, or marble.
Make sure to apply it thoroughly to both surfaces, especially due to their tendency to have pitted surfaces. The weight of these items will require some form of temporary support after applying the adhesive.
Molding Concrete to Accept Attachments
By molding concrete into specific shapes to accommodate attachments, you can establish a much firmer hold. The advantage of creating molded concrete is that this can be done on-site using formwork or shuttering.
Shuttering is usually made of wooden boards bolted together to form the mold. Before pouring concrete into the mold, rebar is added as reinforcement. For more information on rebar and concrete slabs, read our article, “Do You Need Rebar For a 4-inch Slab?”
One example of utilizing the shape of molded concrete structures is hanging signs and billboards (advertising hoardings) suspended from concrete bridges.
The inbuilt strength and accommodating shape of the top of a concrete bridge can securely support the hanging board through the use of tight-fitting brackets.
Insulating Concrete Forms (ICFs)
The unique Insulating Concrete Forms are user-friendly molded wall systems that fit together, much like lego blocks. These are usually hollow blocks of foam with polystyrene or metal ties that you will reinforce with rebar and pour the concrete into (source).
The foam on either side will serve as insulation between the concrete and whatever wall facing you put on it.
The grid pattern of ties within these blocks often serves as hardpoints that you can attach items to by screwing them into the polystyrene or polypropylene instead of the concrete. These hardpoints are marked on the foam insulation so that you know where to place your fasteners.
We have shown you it’s not always necessary to drill a hole into concrete to form attachment points. You have several options depending on the level of strength your attachment requires.
A simple fix might include an adhesive or adhesive-baked hook, while there are other fasteners like hard wall hooks and masonry nails. Powder-actuated fasteners and concrete nail guns are useful for supporting frames and providing a much greater hold.
If you’re in the process of building a structure, there are methods of pouring concrete that will accommodate attachments and fasteners like Insulated Concrete Forms.
Whether you’re a contractor or homeowner, we trust that you find the options useful to you from the information we have given you. Best of luck!