By Jim Bryja
Images couresty of General Shale
When it comes to exterior cladding options, most people believe that construction of a brick wall costs more than a wall constructed with a non-masonry material. However, the perception that brick is only for higher end projects and will blow the budget for cost-conscious builders is simply untrue.
When you consider how masonry products are sold, it’s easy to see why people may be confused about what masonry really costs. Nearly every component that goes into a brick wall is sold on a different basis. Brick is sold by the thousand, mortar by the bag, ties by the box, sand by the ton, and house wrap and flashing by the roll. In addition, masonry labor is charged by the thousand.
Commercial project specifications often contain a brick cost allowance in cost-per-thousand brick. This type of brick cost allowance is meaningless for controlling costs, because a brick with a higher cost per thousand may result in a lower wall cost per square foot. Virtually all other building materials – including other types of cladding materials – are sold by the square foot.
Consumers, builders and architects understand pricing by the square foot, which makes it easier to compare products such as wall-covering materials. Once all the components utilized in a brick wall are converted to a square-foot cost basis, people are often surprised that brick is much more affordable than they think. In fact, when brick is priced by the square foot, the cost is very competitive.
Brick size is another important factor when considering the total cost of masonry walls. For example, the installed wall cost for a king size K/S brick can be as much as 25 percent less than the installed cost for a modular size M/S brick. In general, larger units are typically more cost efficient to install. This fact has long been known in commercial construction, where utility size bricks are recognized as one of the most cost-effective units to install. Larger size units require fewer brick to lay and fewer joints to tool, and generally require fewer movements by the mason per square foot.
Several considerations should be taken into account when changing from one brick size to another.
Some common questions that are raised include:
- How does a different size affect the bond pattern?
- How will corners turn?
- Will the masons agree to lay the new size?
- Will the size of the lintel need to change?
Queen size brick is a good example of how brick size can offer substantial cost savings. A square foot of wall requires only 5.76 queen size bricks versus 7.85 modular size bricks. The larger faced queen size brick also requires less mortar and reduces the installation time. The average queen size brick weighs about 1/4 pound less than a modular size, which is easier on the mason and can significantly reduce shipping costs. The larger face area of a queen size brick also offers the buyer a premium oversize look. Switching from modular size to queen size can result in a wall cost savings of 15 percent or more.
For these reasons, queen size brick has become very popular with builders. Due to the reduced bed depth of a queen size unit, the unit does not turn a corner on 1/2 running bond, but this is no reason to be concerned about the installation.
The most common method of queen size brick installation is to “clip” the corner units and lay the brick on a 1/2 or standard running bond. Clipping the corners simply means alternating corner units to be cut short by about 3/4 inch. The balance of the brick is then laid in a simple 1/2 running bond pattern. Another option is to “squeeze” the corners, where the mason gradually pulls the brick into a 1/2 bond position by varying the mortar joint thickness. Both options have been used with good results, but the clipped corner method would be the preferred choice.
Another common question is how to deal with the reduced bed depth (2 ¾ inches versus 3.5 inches) with respect to the air space, lintel size and framing pocket. All of these issues are easy to address. For residential construction, the air space should be maintained at one inch, which will set the brick back 3/4 inch from a modular size framing pocket. The residential building code calls for a “nominal” one-inch air space, which functions as a drainage space for water to escape the building envelope. The structural capacity of typical corrugated brick ties is based on an air space of no more than one inch, so the one-inch air space is set as both a minimum and a maximum and should not be changed. Keep the one-inch air space and use the corbelling provisions in the code to move the wall out 3/4 inch over the top two to three courses to maintain the pocket.
An additional frequently asked question is how to deal with soldier coursing above windows, since queen size brick course out differently than modular size brick when using soldiers. Again, the solution is simple: combine a brick cut to 4.5 inches together with a rowlock course.
Queen size brick has a bed depth of 2 3/4 inches versus 3.5 inches for modular size brick, so a steel lintel with a shorter horizontal leg can be used. Since queen size bricks weigh 20 percent to 25 percent less than modular size bricks, lighter gauge lintels can be used, resulting in even more cost savings.
Similar cost savings can be realized when using king size brick. In addition, all of the items related to substituting queen size brick for modular size brick can also be applied in a similar manner when using king size brick.
Together, pricing brick by the square foot and substituting queen size or king size brick for modular size brick adds up to one rather surprising fact: Brick is a cost-competitive cladding material for many projects commonly perceived as too expensive for masonry walls. This is especially true when you consider all of the inherent benefits of brick, such as energy efficiency, low maintenance, environmental friendliness and resale appreciation.
Jim Bryja is manager of engineering services for General Shale.