Comparison of Laying Brick Versus Block
Words: Donnie Williams
Brick and CMU (Concrete Masonry Unit) are two commonly used materials in masonry. As a mason, it is important to understand the similarities, differences, pros, and cons of both materials, as well as the variations in layout and measurement techniques, mortar spreading techniques, required tools, daily production differences, and the physical wear and tear on the body.
While writing this article, I spent some time reminiscing about the days when we were finishing up the blockwork on a school and the following Monday, we were starting the exterior brick veneer. I would look into my tool bag to do an inventory of the tools I had. Usually, there were always tools that had mysteriously gotten lost over the last 5-6 months of just laying block. The first thing I look for is my modular ruler and my spacing ruler. Although I could take my tape measure and make a story pole to get by, I'd be way more successful at hitting my heights if I'm prepared with the right measuring tools.
The next tool I look for is a new horsehair brush. While laying block, there is a little more forgiveness on the finish than brickwork, which is the finished product.
To write this article, I wrote the intro and sent it out to many of my friends in the business for their outlook on the matter. Several of them stated that they swapped out to a smaller trowel. The way we spread mortar is completely different. The direction in which the trowel flows, the way we get the mortar off the board, and the way we turn our bodies to spread mortar are different.
There was much discussion on some of the masonry sites I posted on as well. The fact is, there are a lot of block layers out there who can’t lay brick or stone. Many of these block layers are due to areas across the country that don’t have many bricks. Some are trained in block and never have much opportunity to lay brick. Other major discussions were from the stone masons. Stone masonry is an even bigger divide due to the many types of stone. There’s natural stone, manufactured stick-on stone, cast stone small enough to handset, and huge cast stone that has to be set with a lift.
There are a lot of stone masons who can do natural and stick-on stone but would be lost on a commercial job setting stone with a lift. And vice versa, where a commercial stone mason would have trouble finding the right puzzle pieces to make a natural stone job look presentable.
Another major school of thought is the commercial bricklayers attempting their first triple brick arch made of all brick. Getting the cuts just right around the arch is the first thing a mason's eyes look at when seeing an arch. On the other end of the spectrum is taking a residential bricklayer who can build the perfect arch and giving him a 100' long suspended sifter built 100% out of an engineered Halfen system. I am proud to say that I started on brick. We would work on commercial jobs during the week and do residential on the weekends or when commercial jobs were slow.
Here are some of the details of my research with other masons across the masonry world. Let's deep dive into each aspect in detail.
The Similarities:
- Both brick and CMU are masonry materials used for construction purposes.
- Both materials provide structural strength and durability to the building.
- Both require mortar for bonding and stability.
The Differences:
- Composition: Bricks are typically made of clay or shale, while CMUs are made of concrete or cinder.
- Size and Shape: Bricks are smaller in size and come in different shapes, such as modular, queen, king, Roman, and utility. CMUs are larger and have a more standardized shape, typically 16" long, 8" tall with different widths such as 4", 6", 8", 10", and 12".
- Weight: CMUs are generally heavier than bricks due to their concrete composition. The weight of CMU is usually between 28 lbs and 50 lbs, while bricks average between 3 lbs and 5 lbs.
- Cost: Brick is often more expensive than CMU per square foot.
- Installation: CMUs are faster to install per sq ft compared to bricks due to their larger size.
Pros and Cons:
- Bricks:
- Pros: Bricks offer aesthetic appeal, versatility in design, and higher fire resistance.
- Cons: Bricks are more expensive, require skilled labor for installation, and may have variations in size and color.
- CMUs:
- Pros: CMUs are cost-effective, provide excellent strength, and are readily available.
- Cons: CMUs may lack aesthetic appeal, require additional finishes for aesthetics, and can be prone to moisture absorption without proper waterproofing.
Mortar Spreading Techniques:
- Both bricklaying and CMU installation require the use of mortar.
- Bricklaying techniques involve spreading mortar on the brick and then pressing it onto the previous course.
- CMU installation involves applying mortar directly onto the CMU block and then placing it on the previous block.
Tools Needed:
- Common tools for both bricklaying and CMU installation include trowels, jointers, levels, masonry brushes, and masonry saws.
- Bricklaying may require additional tools like brick hammers and chisels to cut and shape bricks.
Daily Production Differences:
- CMU installation usually allows for faster production due to the larger size of blocks.
- Bricklaying may require more time and effort due to the smaller size of bricks and the need for precise alignment.
Physical Wear and Tear on the Body:
- Both bricklaying and CMU installation involve physical labor and can put a strain on the body.
- Bricklaying may require more bending and repetitive motions due to the smaller size of bricks.
- CMU installation may involve lifting and maneuvering heavier blocks, which can strain the back and arms.
The following are quotes from other successful masons in the industry:
Fred Campbell
- With block, you have to shake your mud on the trowel so it'll stick. For brick, you have to roll it up like a pie and leave it loose on the trowel so it slides off easily.
- You lay brick by pushing down and gently shaking the brick back and forth. You lay a block by tapping it with a trowel or hammer or bumping it with your hand.
- Laying brick has more impact on your forearms and shoulders. Laying block has more impact on your wrists and back.
- Personally, I think anyone can lay a block, because it’s a lot easier to lay due to its size. It takes more skill to lay a brick.
- A block is a bigger unit, so it makes it easier to bond out and get heights correct versus a brick since it’s smaller.
- The only difference in tools is I use a tape measure on block and a brick spacing ruler on brick. I use various types of jointers for brick and normally opt for a concave joint on block.
Joe Williams
- Techniques of spreading:
- Brick: When spreading for brick, you need to cut the mortar apart from the larger portion while keeping the trowel full, bringing it above the brick, and pointing it while giving the trowel a clean and sweeping motion along the brick course you need to spread.
- Block: Unlike brick, you do not want a full trowel of mortar. When you cut the smaller portion of mortar from the larger, you need to bump or shake the trowel, causing the mortar to flatten and stick to the trowel more. This is needed to have the mortar stay on the trowel while you loosen your grip and rotate the handle as you bring the tip alongside the block to slide it down its edge, causing the spread to be full and continuous along the sides. Thus, one uses a fluid motion with a tight grip on the handle for brick, while block requires a looser grip and manipulation of the trowel handle.
- While some were taught to shake the brick down, I was taught to roll the brick to the line for speed. This takes a lot of wrist strength and control; some would set the brick flat on the mortar bed and shake it down until it is level with the line or desired joint size. I, on the other hand, was taught to roll the brick in two parts: from front to back and from the heel of the palm to the tip of the fingers. This method is more forceful, but when done correctly, it is faster than the shaking method. Block laying involves a locked wrist, setting the block straight down, and then bumping the corners to the desired position. Having a locked wrist helps with the physicality of the weight and the continuous repetition of laying the heavier block. Bumping the block with the trowel butt helps maintain endurance throughout the day.
- As the day goes on, the wear and tear on the body differs between block and brick. The speed and repetition of laying brick cause wrist fatigue due to the rolling or shaking technique. This also affects the lower back and chest muscles because of the twisting and grabbing of the brick. For block laying, the shoulder and a localized part of the lower back experience more strain, usually on the side of the laying hand, caused by the limited movement from the supply stack to the wall and back. Both processes are taxing on the body with their repetitive movements, but they strain some of the same areas.
- Brick and blocklaying both require strength, agility, and precise movements, but they have different skill sets. Bricklaying benefits from quick hands and precise stopping and starting positions, while blocklaying can be improved by strength. For example, some masons toss the block over the line and catch it with the trowel to lower it into position. Each form of masonry has room for creative techniques to improve and overcome challenges. Both are true art forms.
- Laying brick and block requires different layout skills. A single block covers more area than a brick but has less flexibility in layout. Brick offers more adjustability in different points of the wall.
- My toolbox includes a 12 or 13-inch trowel with a wider blade and high pitch for block and a 10-inch or smaller trowel for bricklaying. The smaller trowel blade enables faster brickwork, while the larger trowel carries more mortar for spreading along the block's edge. For block, I also keep a torpedo level handy for a quick check of the block's level in every direction.
Bricklayer Worldwide Member Responses: Brickwork is finished work, but blockwork can sometimes be a finished product. However, blockwork is more structural than brick. Most blockwork is to replace concrete as an option. It typically takes two hands to lay in most instances versus handling a brick one-handed.
Chad Eber: When laying CMU, you need to understand requirements for rebar, grout, and bearing plates. You also need to know when to use wall bracing or engineer the CMU wall with internal wall bracing. With brick, you'll usually be creating an aesthetic look on a wall, making precision a must. Unfortunately, precision is not always the top concern in our trade nowadays. When done correctly, a brick wall is highly praised by those who know masonry.
Jesse Demler (Slimbrick): Oh man. Blocks go home easier, but bricks are easier on the body, right? With the right mortar, you can get a block to sit where it needs to be, but usually, you have to push a brick to where it needs to be. Blocks are more laborious on the body despite being the "easier" one to lay. However, learning to lay bricks first makes for a better mason because you develop a feel for it more than with block. It's easier to use a Philly trowel on block with more surface area toward the edges versus a London trowel, which is easier to pick up and drop piles of mortar for brick. Layout is simple with block, just 8" and 16" increments, while brick can vary in different sizes. Both are laid by feel, but I use my hands more with brick and the heel of my hand to match the last one versus using the visual of the line and the block below for block.
In conclusion, while both brick and CMU serve their purposes in masonry construction, they have distinct differences in terms of composition, size, cost, installation, and aesthetics. Understanding the variations in layout, measurement, mortar spreading techniques, required tools, daily production, and physical demands can help masons make informed decisions when choosing between the two materials for different construction projects.