Issues with Misaligned Anchor Bolts
Misaligned anchor bolts can be a major headache. Many industries use anchor bolts to attach structural elements, commonly steel, to concrete to ensure stability. One end is embedded into concrete, while the other is attached to the steel structure. Anchor bolt installation requires accuracy, but sometimes anchor bolts are misaligned during installation. This problem can be extremely difficult to fix, but the question remains: can you fix a misaligned anchor bolt?
As with most complex questions, the answer isn’t a simple yes or no. There are many questions to consider when determining whether a misaligned anchor bolt can be fixed:
- When was the problem noticed?
- Is the entire anchor bolt pattern misaligned?
- Have you consulted your land surveyor and engineer?
It should be noted that the last question is most important. When something goes wrong on the jobsite, constant communication is critical. You may be more concerned about acting quickly before the concrete sets the anchor bolts, but communicating with experts should always be your first line of defense.
Quick tip: Surveyors and field engineers are excellent for supervising bolt placement, and some will even place anchor bolts for you. Finding a well-respected land surveyor and field engineer for your next project is a great way to avoid errors on the jobsite.
Setting an Anchor Bolt
To avoid misaligning an anchor bolt, it’s important to follow the American Institute of Steel Construction (AISC) Code of Standard Practice and have technically-savvy team members on site. According to the AISC, a field survey of proposed anchor bolt locations must be performed before the steel is delivered. Having a team of well-trained experts scouting locations and installing the concrete helps avoid misaligned anchor bolts, downtime and unnecessary labor and expenses.
Remember the old adage “Measure twice, cut once?” This strategy also applies to steel construction. Keeping a careful eye on measurements ensures you don’t misalign your anchor bolts. Using a template can help with accuracy and ensure you’re using the right pattern prior to fixing it to the foundation. Approximating positions instead of accurately measuring will cause problems. Ensuring you have the right template in the right place is the best course of action.
Managing Misaligned Anchor Bolts
Misalignments do happen from time to time due to issues with installation. As we mentioned earlier, repair methods vary based on time, placement, and severity of the issue.
If you discover a misaligned anchor bolt before the column base plate has been installed, it could be possible to use a different pattern or plate. This is ultimately the engineer’s decision, so it is critical to consult an engineer when problems arise. If the anchor bolt is misaligned after the column has been set, you can typically slot the base plate and use a plate washer to span said slot.
If the anchor bolts are majorly misaligned (more than a few inches), an engineer may decide to cut off the rods and drill in anchor rods and use epoxy that aligns with your area’s building code. An engineer should be careful to ensure the foundation hasn’t been compromised if going this route.
Ultimately, if you find misaligned anchor bolts during your installation process, communication with experts is the number one priority. Your engineers will be able to troubleshoot the issue and determine whether repairs are possible. For more information, always refer to guides and regulations from the AISC.