Brick or stone arches can add tremendous curb-appeal to any building, and have become increasingly popular in Dallas/Fort Worth home building since the 1980’s. However, many builders and masonry contractors have failed to properly apply the basic principles that insure a lasting and aesthetically pleasing design. Countless arches in local metroplex homes are developing cracks and have loose brick or cast stone, or are falling down completely due to design flaws.
Types of Arches
A semicircular (or “parabolic”) arch has a true half-circle shape and effectively transfers the weight above the arch to the shoulders (abutments). Therefore, in most cases the semicircular arch is structurally self-supporting. However, a major arch (spanning more than six feet) supported only by narrow columns of 12-16” wide—or abutments that are built on separate foundations—can cause even this structurally preferable design to fail.
The even more popular segmental arch (also descriptively called “eyebrow” arch) has a much flatter shape and imposes considerable sideways thrust on its abutments, which must be substantial enough to withstand this pressure. A segmental arch should not be built, for example, between narrow, unsupported columns. For structural reasons, the rise of this arch should be between 1/12 and one-fourth of its span. The flatter and wider the arch, the more likely it is to develop problems, unless it is provided additional structural support.
Minor settling cracks above arches may not require extensive re-design work, but loose brick or cast stone can be quite dangerous and may require a broader scope of repair. Through the help of several structural engineers over the past 20 years, Brick Doctor has developed several arch repair techniques that have proven effective, even on the most difficult arch failures. Some may involve changing the dimensions or shape of the arch, or reinforcing the cavity inside the arch in order to gain structural advantages; others may need to be eliminated altogether in favor of a flat opening, with lintels to support the weight above.
Over the years, our Project Managers and Masonry Repair Specialists have designed and repaired hundreds of arches with excellent long-lasting results (see Testimonials). Let us know if we can help you, too. Contact Us.