How to attach wood to concrete?

Concrete and wood are two very different materials. They have different molecular structures and their surfaces are not well adapted to be naturally bonded.

Unlike wood or metal, concrete is much denser meaning that a standard threaded type screw won’t work, instead, you have to use concrete anchors specifically designed to hold in a concrete predrilled hole as below:

Methods to fix wood into concrete

Concrete fixing gun

A tool such as a concrete nail gun works well if you want to quickly and easily fasten objects onto concrete surfaces.

Although the easiest ways to attach wood to concrete do very little to no impact damage and require drilling instead. A license is also required to operate a concrete fastener, and it isn’t the strongest method, but it is fast.

Toggle bolts

Unique bolts that come with reverse jaws that function as lock wings. These are special anchors commonly used to hang wood parts on a concrete wall (Not offternly used). 

Masonry sleeves

Using a specialized plastic sleeve specifically for masonry fixings that will expand and clamp to a concrete hole upon hammering a nail or screwing can hold wood and concrete together well.

Given that you predrill a hole in the right spot and insert the plastic sleeve.

Concrete anchors (Trubolt, Dyna bolt)

Dyna bolts and trubolts are the most popular and most comman way to join concrete and wood together for anything structual.

These are several types of fasteners meant to work with concrete-based adapters and fittings. In the most basic sense, they’re specialized screws with varying degrees of holding strength.

Threaded bolt

Sitting a  bent threaded rod in wet concrete before it drys with a washer and nut inside the concrete makes for the strongest fixing method.

This is the strongest method for fixing wood to concrete and should be used over the other methods for everything of structural importance. Read more below.

Power tools you can use to attach wood to concrete

Cordless drill

Cordless drills that have the hammer function deliver concussive blows behind the bit which aids in drilling into various masonry mediums. you can use one to pre-drill small holes in concrete. Having a brushless motor can help.

Concrete nail fastener

While any concrete nail gun would do, it’s better to get a Ramset given its long-standing track record.

Similar to a regular nail gun, concrete nail guns are closer to firearms than they are to tools and have more driving power to easily breach the hard surface of materials such as concrete, brick, and slab.

Dyna drill

Also known as a rotary hammer, these are larger power drills that work only with masonry drill bits.

They are capable of generating immense torque while pounding the bit back and forth to break up and bore harder material.

They can drill and chisel concrete with a switch of a setting.

Impact wrench

While it isn’t ideal to use an impact wrench to drill into concrete, it’s very much an essential tool for driving long bolts and fasteners, especially in larger-scale projects.

An impact wrench will save your arm from repetitive strain.

Hand tools that can help you join wood and concrete

Hammer

A hammer is a very basic tool and an obvious choice when attempting to join wood and concrete. Alightweight Titanium hammerwill reduce much of the stress caused by manual hammering.

Though the anchoring might be a little rough around the edges, you simply line up the corners you wish to bond and drive a long enough fastener between them with a few good blows before tightening with a crescent or socket set.

Clamps

You can make the job of joining wood to concrete easier by using clamps to temporarily hold the wood in place while you pre-drill the anchor holes through the wood and into the concrete.

Using a power-operated fastening tool?

The Ramset(semi-automatic) is good for small to medium-scale projects but is more tedious to use if you need holding strength beyond its capabilities.

While it can shoot variously sized nails, anything larger than the nozzle opening won’t be usable.

Also, this is more of a permanent joinery method as gun-driven nails are near impossible to manually remove by standard non-damaging means. 

Also, consider if you hit steel inside the concrete the vibration can shatter the surrounding concrete leaving a messy surface.

When it comes to connecting wood-to-wood check out the other nailer types.

1. Select your nails, around 2-inch or 4-inch nails are suitable for most DIY projects. Not really a necessity, but nails with shear strengths between 100 – 135lbs offer the best results.
2. Load the nail into the nozzle of the gun with the tip pointing outwards. 
3. Unhouse the magazine chamber and load the appropriate caliber bullet (.22mm).
4. Cock back the house and apply pressure to the nozzle to deactivate the safety trigger.
5. Directly point the gun downwards to where you wish to nail, leaving a minimum of 2 inches per nail gap.
6. Fire and remove the shell.
7. Repeat up to at least 4 nails for a stronghold.
8. If you pull the trigger and it misfires, you should attempt to pull the trigger 5 times before again lifting the tool, in case it still does not fire, keep the tool facing down and remove the charge.

How to attach wood to concrete using screws and a sleeve?

Split into two categories by load capacity. These types of fasteners are popular choices for most home interior and exterior projects. 

Light-duty (up to 50 lbs)

Materials needed: Hammer drill, power screwdriver, plastic anchors, masonry drill bit, and a hammer

Best uses: Concrete, brick, mortar, stone

Procedure:

1. Mark and drill pilot holes. 
2. Drill until the masonry bit is at the depth your screw will penetrate into the concrete.
3. Tap the plastic anchor into the hole.
4. Drive the screw through the timber and deeper with a hammer into the sleeve in the concrete. 

Limitation/s: Sleeves may break free as you turn the screw if the material is soft/loose, or if the hole pre-drilled is too big. Every time you replace the screw you will need to insert a new plastic sleeve.

Medium-duty (up to 100 lbs)

Materials needed: Hammer drill, 3/16” concrete screws (hex and Philip’s heads)

Best uses: Concrete & concrete blocks

Procedure:

1. Mark and drill pilot holes. Use a special drill bit compatible with wood for drilling in the wood and the concrete.
2. Place the screw and drive it in with an impact driver, cordless drill, or impact wrench.
3. Tighten until secure.

Limitation/s: Screw tips can often break due to the extreme hardness. Not effective on crumbly concrete and mortar. 

How to attach wood to concrete using heavy-duty anchors?

There are 3 popularly used heavy-duty concrete anchors, mainly wedge anchors, threaded rods, and Dynabolts. Wedge anchors can take on extreme loads, while threaded rods help strengthen structural junctions. Dynabolt sleeve anchors are easy to install and can effortlessly hold down up to 200-pound loads. 

Materials needed: Hammer drill, carbide drill bits, Trubolt(wedge anchor); threaded rod; or Dynabolt, wrench. 

Trubolts

Procedure:

1. Mark and drill through the fixture depth into the concrete. Use bits the right size as the anchor as specified.
2. Insert the anchor and tap it into place.
3. Set the washer
4. Then thread the nut for a couple of turns until tight using a wrench.

Threaded rods

Procedure 1 (Embedded in wet concrete) :

1. You can set threaded anchors into the concrete before the concrete completely dries with a nut and square washer on the concrete embedded side to secure it from the uplift.
2. Later you can predrill a hole in the timber (Bottom plate), set it over the threaded rod, and attach a washer and nut.

Procedure 2 (Embedded in  dry concrete) :

1. Drill a hole in pre-existing concrete 3-4 mm bigger than the size of the threaded rod to allow room for glue.
2. Clean out the hole with a wire brush first then a blower.
3. Fill the hole with appropriate concrete adhesive up to about ⅔ the depth.
4. Push down the threaded rod, twist it, and allow it to sit without movement. 

Dyna bolts

Procedure:

1. Drill diameter-specific holes through the concrete.
2. Clean out the hole and make sure it’s free of debris. 
3. Insert the Dynabolt through the fixture or washer and hammer into place until the washer contacts the fixture surface.
4. Tighten using a torque drill while pushing down on the fixture to allow the sleeves to twist and tighten. 

Limitations: Most heavy-duty concrete anchors are permanent or more difficult to remove once installed. 

How to attach wood to concrete using toggle bolts?

Toggle bolts are great options for when you want to hang things on thinner concrete walls. With toggle bolts, you can hang almost anything! You simply have to either use more toggle bolts or get bigger ones. It really depends on what you want to attach.

Materials needed: Hammer drill, power screwdriver(optional), toggle bolts

Procedure:

1. Mark and drill your fixture and pilot holes.
2. Once you’ve identified where you’ll drill, you need a masonry drill bit that will leave enough clearance for the toggle to slide through.
3. Line the toggle with the hole, push in.
4. Screw tight with a power screwdriver. 

Limitations: This will require you to be able to drill fully through a concrete wall, if the other side of concrete has a visual appearance that is relyed on you cannot use this method. Also if the other side of the wall is used for waterproofing you will not want to make a complete hole in a concrete wall.

To drill or not to drill holes?

Ideally, you’re going to have to drill holes, unless you set threaded rods into the concrete before it dries.

Make sure to drill correctly sized holes as specified for each concrete fixing otherwise it won’t work. And to reach higher degrees of holding strength.

On the other hand for quick fixing into concrete, an automated concrete nailer can do the job but don’t expect anywhere near the same holding strength as a concrete anchor.

Can you attach wood to concrete without drilling holes?

There are two ways to attach wood to a concrete wall without drilling.

Using an automatic concrete fastener

An automatic (Ramset) concrete nail gun works in a similar way as a semi-automatic or single-shot concrete fastener gun does.

The thing with an automatic model is the added speed since it can inlay nails at a faster rate.

Tips

• Work fast by always making sure that the tool is oriented exactly perpendicular to the workpiece, whether horizontal or vertical. 
• Layout spacing beforehand to maximize its rate of fire.
• Has decent horizontal side-to-side holding strength.
• Can fix and hold the wood in place before drilling and inserting a  proper concrete anchor like mentioned above. 

Things to note

• Can sometimes break away concrete on the surface of the pin hits steel or a hard spot. 
• Less effective on smaller pieces of wood that could split.
• A license is required for operation.

Using adhesives

Tips

• Choose only from among 2 grades of viable glue: all-purpose construction adhesive and specifically designed two-part epoxy.
• Always prep and clean surfaces before applying to ensure a stronger bond.
• Apply the adhesive on the adjoining concrete surface. Use a zigzag pattern so that it spreads more evenly when you press the pieces together. 
• Work on a flat surface as much as possible to maintain symmetrical results.

How to attach wood to concrete using adhesives?

As stated before, there are only a limited number of types of glue that work for holding wood and concrete together. One of the best and easiest ways of attaching wood to concrete using adhesive is by using epoxy glue, more specifically, epoxy designed for adhering wood to concrete. 

Materials needed: Epoxy glue, applicator, rag/cloth, chisel, or electric sander (optional)

1. Prep and clean the surfaces to be bonded. Use a chisel or electric sander, depending on which is more viable. 
2. With a brush or applicator gun, load up the epoxy and apply it in a consistent zigzag manner.
3. Carefully press the pieces together. Any excess epoxy that seeps out the edges you simply wipe with a cloth or rag.
4. Allow curing for at least 24hrs. Recommended curing for 72 hrs for maximum strength. 

On its own, wood-to-concrete epoxy has a tensile strength of 5020 PSI – which’s roughly 1.3 times stronger than the bite force of a saltwater crocodile, which can easily break through bone as if they were twigs. 

Limitations: Besides long curing times, epoxy is also sensitive to heat and water, so applications near bodies of water or in areas with high humidity make it significantly less effective.

Best fasteners to use for different applications

The best way to attach wood to concrete normally depends on the hardware material and fasteners you’ll use.

Wood rail to concrete

Rails are often attached to stairs and walkways and need to be sturdy since they serve as additional safety measures. Use medium to heavy-duty sleeve anchors when attaching wood railing to concrete.

Wood fence to concrete blocks

Fences can be both for aesthetic and security purposes. For lighter fences, use standard galvanized or stainless screws with a sleeve. For perimeter fences, use an anchor bolt.

Wood framing bottom plate to concrete floor

Most commonly for framing, you can first fix the bottom plates down with ramset pins followed with Dyna bolts or thru bolts when more strength is required like in the corners, by doorways, and at spacings specified in your local building code.

Wood stud to concrete wall

Mostly similar to how you would attach a wooden frame to a concrete floor, but using anchor bolts like Dyna bolts yield better results.

Wood to concrete ceiling

If you want to fix the top plate of a wall with a concrete floor above you’re better off using Dyna bolts, light to medium-duty sleeve anchors, or a concrete nail gun at intermediate joints.

Wood steps to concrete slabs

Depending on the size of the steps, you can use galvanized or stainless steel Trubolts for a safe hold.

Wood posts to concrete slab

Attaching wood posts to concrete often requires that you place a fitting that’s anchored into the concrete before it dries which the post then slots into.

Otherwise use heavy-duty anchors and concrete fastening with rods and epoxy glue.

Wood beam to a concrete pier

Similar to attaching wood posts to concrete slabs, wooden beams to concrete piers are often the same but with hardware with higher corrosion resistance. Heavy-duty anchors and fasteners work best here for maximum stability.

Conclusion

There may be a lot of fasteners, but the practice and technique of attaching wood to the concrete are relatively the same across a wide range of applications.

Whether it’s attaching a wooden coat hanger to drywall or framing a small shed in the backyard, the important things to have are plastic sleeves, Dynabolts, Trubolts, or a threaded rod and concrete epoxy glue for maximum holding strength in the most structural demanding applications.

Don’t forget a good dust-free hammer drill. It’s time to get drilling!