As our understanding of materials and machinery continues to improve, so too do our abilities to make use of those new technologies.

While the age-old method of constructing a home over a wooden frame is as reliable as it has ever been, new methods have come about over the years that seek to improve on the drawbacks of the old, with prefab modular homes and steel frame construction leading the charge. 

In this article, we will be focusing on one of those methods. So what is Dry Stack Construction, how does it work, and when should you use it for a home build? Learn all about it after the jump.

What is Dry Stack Construction?

Dry stack construction, in the simplest terms, builds structures by stacking together concrete blocks without using any mortar to fill in the gaps in between the blocks. 

Instead, the concrete blocks are placed together in such a way that there are only minimal gaps between them. Sealing the whole thing is a high strength, surface-bonding cement that is applied to both sides of the wall to create a strong, self-supporting structure.

How to Build with Dry Stack Concrete Blocks

Constructing a house with the dry stack technique is a fairly intensive process, arguably more so than the typical method of building with concrete blocks and cement. Below, we examine the general steps of constructing a home’s main support structures with this method.

Foundational Stack

Building with dry stack concrete blocks starts with the first course of the blocks, which are set onto the foundation with mortar. Of course, there is no mortar used between the blocks; instead, they are laid down as close to each other as possible. 

This first step of dry stack construction is arguably the most crucial, as the blocks of the first few rows (or courses) have to be perfectly leveled to avoid any problems with gaps and alignment from coming up when it becomes too difficult to fix.

While there is a level of precision required when putting together the concrete block courses, imperfections in the concrete blocks themselves cannot be avoided. For this reason, some blocks will usually be cut into shape to more accurately fit the wall.

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Every few courses, the blocks should be checked for alignment and filled in with sand or gravel except for corners and certain regular intervals of the walls, as we will see in the next section.

Bond Beams

Bond beams are essentially pieces of rebar that are installed into the concrete blocks to add further structural reinforcement. 

The installation of bond beams is a two-stage process that begins with vertical rebar installed into the cores of the concrete blocks at regular intervals. The horizontal bond beam will then wrap around the vertical rebar to provide the tension that ultimately reinforces the wall structure. 

The bond beam is typically installed only once in a standard-height storey—specifically in the fifth course of the wall—but two may be used for additional strength. More than one bond beam in the middle of the wall is generally unnecessary as the top of the wall will also have one.

Wall Anchors

Where bond beams are used to give reinforcement along the length of a dry stack concrete wall, anchors are used to reinforce the concrete blocks when they meet at a corner. 

To install these wall anchors, holes are drilled into the joint of the concrete blocks, after which rebar is inserted into both blocks and left exposed. 

The reason why these anchors are left exposed in the cores is to get as much of the rebar held together by cement when the cores are poured together, resulting in a very strong joint. The process is repeated at regular intervals to maintain reinforcement across the height of the wall.

Windows and Arches

To build windows and arches (including doorways) with dry stack concrete, builders will use steel beams across the gaps in the walls as the main support structure before the sealing cement is applied. The concrete blocks will be cut to fit the notches of the beams, after which they will be placed onto the beams as normal. 

Topping Off

The top course of the dry stack concrete wall consists of another bond beam setup, and is constructed in the same way as the previous bond beam in the central layer of the wall. 

On this top layer, however, J-bolts are installed into the bond beam on the places where they intersect with the vertical rebar. These J-bolts will be used as anchor points for the roof of the house that will come later. 


Finally, the end of the dry stack construction process is done by sealing all of the concrete block faces with surface-bond cement (a special fiberglass-reinforced cement), which is applied to both sides of the concrete walls at about 1/8″ to 1/4″ thick.

As with the first step, a bit of precision is required when applying the cement, as all of the tiny cracks and gaps left behind in the installation of the concrete blocks have to be properly sealed. 

Pros and Cons of Dry Stack Concrete Block Construction

Now that we are aware of the process that goes into dry stack concrete block construction, what makes it better than other methods?

For one, the higher density of concrete and high strength bonding of the cement makes the wall much stronger than the typical method of using blocks and mortar. The gravel- or sand-filled cores also serve as a minor insulator (although we do recommend installing rigid foam insulation in addition to the wall).

On the other hand, this construction method is often only restricted to building single-storey structures—after all, it is very difficult and dangerous to have freely-stacking concrete blocks at heights where wind becomes forceful enough to knock them off. 

As we’ve mentioned previously, a lot of care and precision is required throughout the entire building process because of the possibility of major reworks that could happen should a single block be misaligned during construction.

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Matt Greenfield

Matt Greenfield is an experienced writer specializing in home improvement topics. He has a passion for educating and empowering homeowners to make informed decisions about their properties. Matt's writing focuses on a range of topics, including windows, flooring, HVAC, and construction materials. With a background in construction and home renovation, Matt is well-versed in the latest trends and techniques in the industry. His articles offer practical advice and expert insights that help readers tackle their home improvement projects with confidence. Whether you're a DIY enthusiast or a seasoned professional, Matt's writing is sure to provide valuable guidance and inspiration.

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