Questions surrounding building integrity and the need for building inspections have been in the headlines for weeks. From concerns around “sinking” skyscrapers to the impact of harsh coastal weather, the structural integrity of buildings is a hot topic. It’s not just building owners and managers who are taking notice. Localities around the country are poised to explore new requirements for structural inspections, especially for older structures.
We wanted to learn more about building inspections and structural integrity, including why they’re important and what to look for. This week, we sat down with Structural Division Manager Dave Spriggs, PE and Geotechnical Engineering Division Manager Jeff Huffman, PE, F. ASCE to discuss structural inspection requirements, timelines, and critical points.
Spriggs has more than 45 years of experience in the analysis and design of structural systems for industrial, commercial, and institutional buildings. He is well versed in the complexities of integrating new structural elements into existing architectural and mechanical features. Huffman has more than 33 years of experience in geotechnical engineering. His areas of expertise include forensic investigations, retaining wall design, and deep and shallow foundation design. Answers have been edited for length and clarity. View more about our team here.
Q: Who is qualified to perform building inspections?
Dave Spriggs: That depends on what you’re looking for. If you’re interested in mold remediation or just a mold study, you’re going to call an environmental specialist for that. But if you’re looking for an investigation of possible settlement on a building, you might call a structural engineer or a geotechnical engineer because you have questions of the water table, soil quality, things that might have changed over the course of time. Building inspectors employed by localities, who many people may think of immediately, are often not the right expert to inspect an existing structure as they generally have not been trained in forensic investigations.
Jeff Huffman: A building inspector or building official is not necessarily the right person for the structural inspection. Building Inspectors are trained in building code compliance, not in the design of structures nor do they have experience with how changed conditions affect a structure. Rather, it needs to be somebody with professional engineering or architect credentials. Now anyone can take the first step of an inspection. If you see something with your powers of observation that doesn’t make sense or looks different than it has been for years, you can be the one to start the process to get someone who is professionally qualified on-site to perform an inspection.
Q: Who orders building inspections?
Spriggs: Building inspections aren’t part of the building code. If an owner wants to protect their investment, they can order an inspection. Localities can also require building inspections, but many don’t. Although, we suspect that might change and more localities will explore requirements for building inspections going forward based on what’s happened recently across the country.
Q: From your respective fields, what are things you would look for in building inspections?
Huffman: From a geotechnical standpoint, it typically is going to revolve around doors and windows that don’t work and cracks that people are noticing. And of course, if it’s masonry, you’re going to start seeing 45 degree cracks coming off the top of doors and other wall openings. That typically means we’re looking at a geotechnical foundation issue.
Spriggs: One aspect of a property that has an influence on both structural and geotechnical concerns is site water. Is site rainwater directed away from the building, or is it collected at the building? If it’s collected at the building you have the potential for water affecting the subgrade soil under the building’s foundations.
With structural, particularly we would look for cracks, the things that Jeff had flagged about doors not opening, that would be picked up as structural as well. We look for excessive deflection on floors. We look for things that may be tilted. We look for evidence of water penetration in the building. Water is not a good thing to get into the building envelope. And if we saw a water stain, we would probably want to investigate further because it could be a simple condensate leak from a pipe, or it could be symptomatic of a bigger issue.
Q: For a less experienced engineer or inspector, what are some things that could be easily missed?
Huffman: One thing I’ve said over the years in my forensic work is I’ve never encountered a failure that occurred because of just one design or construction flaw. It’s always a combination of two or more flaws coming together at the same location on the project that has caused the failure. Engineering experience is a learned skill through specific education and knowledge passed from seasoned engineers to the next generation of engineers. A younger engineer is more likely not to realize the combination of conditions that can come together to potentially cause a failure.
Another issue is practicing outside your area of their expertise. Dave and I have worked together on a number of these inspections because both areas of expertise are required.
Spriggs: Typically, you get called to a project to look at a building, to look at a specific condition, and so you just want us to focus on that; call it tunnel vision. It’s hard to get out of that tunnel vision mindset, and if the client is calling you for a specific thing, they’ll only worry about that one thing. The younger engineer may be a little reluctant to step out of the sandbox, out of the comfort zone, and take on maybe more than he or she should. It’s also a fine line. You don’t want to create more work for the client’s project, but on the other hand, if you go to that project and you miss something you may have eroded your credibility. The owner’s contractor can come back and ask, “Why didn’t they find that broken joist? We had two structural engineers on this project and they both missed that. What’s up with that?” It’s a little thing, but it has big implications.
Another thing a younger engineer might forget to ask is to see the roof. What’s happening on the roof can have implications many stories down.
Q: What factors might lead an owner to have their structure inspected more frequently?
Huffman: Well, we as engineers like to use the word phrase “it depends.” It really depends on the type of structure and the environment it is in. If you’re in the coastal areas with the sea and salt water environments, that’s more detrimental to a structure without a doubt. It’s a harsh environment. It also depends on the age of the building, for sure. It should be inspected more often as it gets older, just like you physically, you start going to the doctor more and more as you get older.
Spriggs: We’ve talked with an architect that we had worked with in North Carolina, and they pointed out that they’ve seen stainless steel corrode at their oceanfront construction. You can also find similar problems in colder environments that use salt to de-ice roads. The cars carry that salt into structures like parking garages and coupled with the fluctuating temperatures and snowmelt, it can corrode the steel reinforcement of the concrete structures. I would suggest an owner of a building like that get it inspected every five years or so.
But if you’re in a part of the country that’s not picking up a whole lot of wind load and not a whole lot of seismic load, you’re not getting the major threats to the structure that you might get in other parts of the country, so it wouldn’t need as many inspections. So it is, as Jeff had said, very much so a case-by-case situation. It’s not a one size fits all approach to inspections or building deterioration.
Q: It’s common knowledge that a building’s settlement can cause cracks like you’ve described. Are those something an owner should be concerned with?
Huffman: It’s worth noting that buildings don’t settle forever, and they don’t start to settle decades after they’ve been built. Typically, settlement occurs as the structure is being built and depending on the size of the structure and the speed with which the structure was built, it will typically occur in the years immediately after construction. If you’ve got a structure that’s been in place for 20 or 30 years, and all of a sudden, somebody says there is a crack that started and has grown to be a half-inch wide, something has changed that needs to be addressed.
Spriggs: Yes, a crack after that many years means something has changed; it could be something major like an earthquake, or it could be something sneaky, like an underground plumbing leak that affects the soil around the footing.
Q: What would you say to an owner who is asking, “Does my building need an inspection?”
Huffman: One thing facility owners should realize is that there is no problem or issue that fixes itself. And no problem ever gets better with time; it only gets worse with time. There have been recent examples where if issues had been properly addressed five to 10 years prior, it would have never escalated to the level it did. You need to address concerns as soon as you can. And it affects your costs, too. So, to answer the question, whenever you see anything out of place, a crack, a sinking of the floor, unusual leaks, it is worth the inspection cost for your own peace of mind and to potentially save you money and larger headaches down the road.
Spriggs: Oh yeah, the cost of deferred maintenance is high. Deferred maintenance is maintenance that’s been put off and it’s always much more expensive and sometimes much more difficult.
Q: Is there anything else you’d like to talk about?
Spriggs: Sure. The big thing, and Jeff and I talk about it from time to time, is if we are seeing problems, we’ll jump to pretty quickly is what is happening with water on site. Because if we can keep water out of the building and we can keep water away from the building, you’ve eliminated a lot of sources of problems.
Huffman: Many structures, including commercial buildings and residential homes, have cracking or basement wall or slope problems that many times are the result of a changed condition on the structures’ property or on an adjacent property that is directing water to a detrimental location. Controlling water and looking at the broader picture are important issues as Dave mention earlier.