Block walls can serve a number of different applications. From commercial or residential, and from being indoors or outside, block walls will be great for their decorative appeal and for their resistance to the natural elements. Accurately estimating a cost can be done by knowing the purpose of the wall, being familiar with local building codes, and being aware of the size and length the wall should take. Each wall will be different in cost because of all of these factors, and the material and type of block you decide to use will also cause the cost to fluctuate. Sometimes a simple calculation can be done to figure out the pricing of constructing a block wall. Determine the amount of material it will take to build the wall, the concrete and forms needed to create the wall’s footer to determine the total cost of the block wall.

This will include the cost of concrete, mortar, lumber and blocks in creating the wall  However, if this wall is being built on an existing foundation, then a footer is not needed. Consulting local building codes will also help because sometimes cities will require certain features to be installed such as drains. 

There are many online calculators that will provide a ballpark cost estimate. Another way if you don’t want to do it yourself is by having a contractor survey the area and determine an accurate price that factors in all the materials that will be needed to create the wall.

There really is no limit to how tall a concrete block wall can be, but there may be limitations that impede a wall from being any taller. Concrete can be poured up to 32 feet high from cranes, but after that it may be more difficult to pour concrete or raise blocks. Also, generally a permit from the city will be needed if a block wall will be higher than 4 feet high. When building a block wall, it will be important to know what type of elements or use it may experience. Building to the right height to match your needs will be best. For residential applications, block walls will probably not be as high and may be around eight feet if you are thinking about blocking out the neighbors. Commercial buildings may more often use higher block walls depending on the business. No matter how high the block wall needs to be, it will be the structural support that will allow it to stay steady and firm.. With that in mind, there are a number of different ways to support block walls so that they withstand the elements and time. Blocks in this modern era are built with hallowed gaps that allow rebar or some type of steel to pass through them without being seen on the outside. This will allow for a clean finish, and the ability to further strengthen the block wall. No wall should be built without supports. Even block walls that are two feet high should have an inner system of steel rebar to keep it sturdy.  

Generally walls inside a home are about 10 to 12 feet long depending on the depth of footings. These walls will usually utilize 1/2- or 5/8-inch rebar to give support; however, shorter walls and non load-bearing walls can use a thinner bar that’s about 3/8-inch. Another feature that will allow block walls to be built higher will be the addition of a footer. A footer will increase the size of the base to help the wall become more stable. Often this wall foundation will extend out a foot on each side and be a foot deep. The wall will need to be leveled so that maximum support can be provided allowing the wall to be stronger and taller if needed. Sometimes people will fill cinder blocks to create a solid wall. This is not necessary, but may help to create a taller wall. These cinder blocks may not be as be as strong as concrete walls, so anyway to strengthen them may help.

Calculating a block wall will allow you to know how much the wall will cost and how much of each material to purchase. Luckily concrete blocks are an affordable building material that can be used for a variety of different reasons and repurposed for different applications. Calculating the amount of blocks needed to create a wall can sometimes be challenging, but luckily there are online calculators that can help in determining an estimate. For example, online calculators will ask for the desired dimensions of the wall, and the calculator will shoot out a number of how many blocks to purchase. For example, 8ft x 10ft wall will cover about 80 square feet and need 96 (16” x 8”) blocks to fulfill the desired dimensions. Additionally, some calculators will give you the amount of sand and mortar to help create the wall. For our example above, the calculator determined that 3 bags of mortar will be needed, along with 0.43 yds3 of sand. This will give you the amount of materials needed, and some may provide costs for each material. However, the cost provided will not take into account the type of materials you buy and the current costs in your area.

However, for those of you who would like to figure it out on your own, there will be a few steps that need to be understood to accurately determine the amount of blocks. There are several formulas to figure out how many blocks are necessary for a wall project, but the first step will be to measure the width and height of the desired wall. The formula will need the dimensions in feet, so just remember that there are 12” in a foot if you need to convert the number into feet. After gaining this information, you will multiply the height and width. After this it would be good to determine the size of the block that will be used. There are a number of different dimensions of blocks that are used, but the most commonly used is a 16” wide x 8” tall block. You will multiply 16 and 8, and then divide by 144. For this specific block, the value will come to .89. This value will then be used to divide the square footage of the wall. So the formula will be: Number of Blocks Needed = Wall Square footage ÷ Block Square Footage. 

Although this value will give you a precise number of blocks needed, you may want to buy extras to account for broken blocks. Usually about 5% to 10% more blocks is recommended for each project.

Determining the number of bags of mortar will depend on the type of mortar you plan to use for the joints of the wall. On average, it will take about three bags of mortar for every 100 blocks that are used. To more accurately determine the number needed, you will take the number of blocks that will be used and divide by 33.3. Typical mortar bags will require a 1:3 ratio of cement to sand. This boils down to about 1yard3 of sand to every seven bags of cement. Again the type of mortar and blocks will change the values and formulas, but if you are able to figure that out, then you will be able to receive an accurate number of the materials that you will need. Contact us for a estimate 
​