Read the August 2012 Quarterly Newsletter here. Subscribe to our blog in the sidebar to get email updates as new items are posted throughout the year.
Category: Facade Inspection
The Role of Time in the Care of Buildings
When planning exterior repair projects, project teams sometimes speak of 20-year repairs, 30-year repairs or even 50-year repairs. These are the anticipated life spans of the major repairs carried out, with the expectation that the repair work will withstand the elements of weather and material degradation for one or two generations. The reality is that with most historic buildings, it is idealistic at best and dangerous at worst to expect major repair projects to completely eliminate the need for ongoing periodic maintenance and repairs. In some cases, the ongoing repairs required between major repair campaigns can be quite extensive. There are many variables that contribute to the longevity of repairs, including the original materials and repair materials, construction details, quality of work, climate and time itself.
In our work surveying monumental historic buildings, Vertical Access has the opportunity to see building systems of varying ages and degrees of deterioration as well as many generations of repairs installed to address this deterioration. Sometimes our investigations are part of the discovery phase of a major repair project, intended to be one of those 20-year or 50-year repairs. Other times, our survey work is part of a public safety inspection, either city-mandated or as part of a building owner’s self-mandated schedule.
Case Study: Two Historic Stone Churches
Looking at two examples of historic churches in the Northeastern United States, one a brownstone church and the other constructed of marble, the role of time in planning repair projects becomes more clear.
Delamination of brownstone seen at the darker red ashlar units. These units are face-bedded and of a different chemical and granular composition than the other ashlar units.
Some brownstones, when used as a building stone, are notorious for their poor weathering characteristics. The laminar nature of the stone and physical composition of many types of brownstones make them susceptible to ongoing deterioration. Vertical Access recently surveyed the exterior masonry of a brownstone church after church officials noted some pieces of brownstone that had become loose. The last major repair project at the church was carried out in the early 1990s, about 20 years ago. Repairs to the exterior masonry included retooling the brownstone and installation of replacement units.
In its recent survey, VA found that the the replacement units were in very good condition and most areas of retooling were sound. However, those brownstone units that appeared to have a finer matrix and different clay content suffered from more widespread delamination and erosion. The deterioration noted at some units is due to their face-bedded orientation and at others to the large surface area of stone at some of the carved elements. From the hands-on survey that VA performed, it is clear that the 20-year mark is past the lifespan of the repairs that were carried out for some of the stonework of the exterior.
Removal of marble at ornamental unit during a periodic inspection for public safety.
In the case of the marble church, a major restoration was carried out over 30 years ago. Planning for the next major restoration began almost 10 years ago, with a full survey of the exterior masonry. Public safety inspections were performed periodically during the design phase of the exterior restoration. As with the brownstone church, the public safety inspections of the marble church identified material deterioration of concern. Finally in 2012, construction for the major restoration project has begun.
These two examples of historic masonry churches illustrate the role that time can play in planning a repair project. Often we have unrealistic expectations of how much time our repairs will last. This may lead to concerning or even hazardous conditions developing on our buildings before a plan is in place to address them. Ideally, periodic inspections made in the interim between major repair campaigns will improve both public safety and capital planning for the facility.
The Quarterly – April 2012
Read the April 2012 Quarterly Newsletter here. Subscribe to our blog in the sidebar to get email updates as new items are posted throughout the year.
Radio Frequency Safety: An Update with a Recent Perspective
On many Vertical Access projects, we work on roofs or the sides of buildings where there are radio frequency (RF) antennas. Part of our site-specific safety check always involves assessing the risk posed by RF antennas, and we have discussed Radio Frequency Safety in a previous newsletter article. In most of our projects the small number, low power or location of the antennas relative to where we perform our work means that there is little risk from the existing antennas. However, during a site visit a couple months prior to the scheduled field work for the hands-on investigation of the LeVeque Tower in Columbus, Ohio, we noticed a concentration of large antennas beyond what we typically encounter. Below are some of the RF issues that were thoroughly discussed and reviewed both internally and with the project team prior to the inspection. The information presented in this article, intended for those who may come in close proximity to antennas as part of their work but who do not necessarily have training in RF safety, is provided only as general background. Further information is available from some of the links included in the article. In addition, training including basic RF awareness is recommended for those who may be exposed to radio frequencies as an indirect consequence of their work near RF antennas.
RF antennas at top of the LeVeque Tower
The Federal Communications Commission (FCC) is the government body that is responsible for evaluating the effects of FCC-controlled transmitters on the human environment and for developing regulations for Radio Frequency Safety. The FCC’s Rules and Regulations (Title 47 CFR) incorporate recommendations from organizations such as the American National Standards Institute (ANSI), the Institute of Electrical and Electronics Engineers, Inc. (IEEE), and the National Council on Radiation Protection and Measurements (NCRP). In addition, the FCC’s Office of Engineering and Technology publishes information bulletins, such as OET Bulletin No. 56, “Questions and Answers About the Biological Effects and Potential Hazards of Radiofrequency Electromagnetic Fields.”
The FCC requires licensees to assure that that people are not exposed to RF power densities in excess of the applicable Maximum Permissible Exposure (MPE) limit. The FCC defines two tiers of permissible exposures differentiated by the situation in which the exposure takes place and/or the status of the individuals who are subject to exposure. General Population/uncontrolled exposure limits apply to those situations in which persons may not be aware of the presence of electromagnetic energy, where exposure is not employment-related, or where persons cannot exercise control over their exposure. Occupational / controlled exposure limits apply to situations in which persons are exposed as a consequence of their employment, have been made fully aware of the potential for exposure, and can exercise control over their exposure. For an area in excess of 100% Occupational MPE, access controls such as locked doors, signage and administrative policies must be instituted.[1]
Electromagnetic energy includes radio frequency radiation, the portion of the electromagnetic spectrum in the 30 kHZ to 300 GHz range, and is present everywhere. Occupational RF exposure limits relate to the hazard of bodily heating. The eyes and testes are the most susceptible to heating due to low blood flow. A secondary hazard of RF energy is the energization of conductive structures by strong electromagnetic fields. Without any loose wires or stray currents, it is possible to get shocked by an energized structure. RF energy may be dangerous if there is direct contact of an energized material, if the power density is high (such as from multiple sources) or if the exposure time is long. Symptoms of RF exposure are similar to altitude sickness and can include listless or confused behavior, sore joints, dizziness, headaches, bad taste in mouth, blurred vision or nausea.
If working on a building where RF safety is a concern, it is prudent to request a compliance report. The FCC mandates that RF emission levels for any site with an FCC-controlled transmitter be calculated and kept on file. This file must be updated if there are changes to the RF environment. An RF compliance report or emissions study provides additional information. It is a comprehensive evaluation of the emitted electromagnetic energy and RF transmissions, with the findings compared to FCC guidelines for human exposure.
If and RF emissions study or compliance report identifies potential RF hazards, several steps can be taken to mitigate RF exposure when working near antennas. The most straightforward action is to turn off the antennas. Depending on the purpose of the antennas, this cannot always be achieved. Understanding what types of antennas are present in a work area and the specific exposure associated with each antenna, it may be possible to create a temporary controlled access area to avoid entering an RF field that exceeds the MPE. Another mitigation measure is for personnel working near transmitting antennas to wear RF suits. These head-to-toe suits, composed of flameproof Nomex and stainless steel, attenuate the RF signals to reduce their effect and may be appropriate where there are strong RF fields.
Another measure to consider is the use of personal RF monitors. Although personal monitors do not directly mitigate the RF exposure, they do indicate what the exposure at a particular location is. When performing the exterior condition survey of the LeVeque Tower, each technician used a Nardarlert XT A8862 personal RF monitor, capable of detecting frequencies from 100 kHz to 100 GHz . These monitors give an audible and vibratory signal when the field levels above a preset limit are detected. If levels above a certain limit are detected, the user then knows that she should move to another area immediately or limit the amount of time in that area, depending on the reading.
It is important to know that the transmitting signals from two-way radios may exceed 100% MPE as detected by personal RF monitors. We quickly discovered this at the LeVeque Tower when using our Motorola radios, which we always use for on-site communication between technicians. In the case of our radios, this does not become a health concern unless the radio is used in transmission (talk) mode, as posed to the default receiving (listening) mode, more than 50% of the time it is on. As a corollary, the antennas on the building may also interfere with two-way radio signals, creating static or complete disruption of the radio signal.
In the case of the LeVeque Tower, Turner Construction and the property manager shared our concern over RF issues and were extremely cooperative. Prior to the scheduled fieldwork they commissioned an updated RF Compliance Report that focused on the areas where we anticipated working. Most importantly, they turned off the most powerful antennas during our working hours to greatly reduce the RF exposure. During the five days of fieldwork, with each technician wearing a personal RF monitor, we did not encounter RF fields above 100% MPE from the existing antennas. The comfort gained by learning about general and site-specific RF issues before the inspection and the assurance provided from the personal RF monitors used during the inspection were key components to the successful completion of the project.
[1] Waterford Consultants, LLC, “On-Site RF Emissions Compliance Report,” pepared for LeVeque Tower, dated March 28, 2012.
The Faces of LeVeque Tower
In Rome’s Capitoline Museum are preserved portions of the Colossus of Constantine, a marble statue of the emperor who ruled over the Roman Empire in the beginning of the 4th century CE. The head of the statue, which depicts Constantine’s “Sacred Countenance” gazing over his earthly domain, measures nearly 8 feet tall. A bit closer to home, a six-foot tall face carved in a similar abstract style looks across the Scioto River valley in Columbus, Ohio. The six-foot tall face of the Columbus “Constantine,” made of terra cotta, is one example of the ornament that adorns the facades of the LeVeque Tower and adds to the character to the monumental building.
[slideshow]
When standing on the ground looking up, the LeVeque Tower looks big. When face-to-face with the two-story tall winged-figures at the corners of the building, one quickly realizes the building is BIG. Although the building has Art Deco touches, mainly in its interior, classical references are the dominant ornament on the exterior. These include rondelles with helmeted figures in profile and the date of 1925 in Roman numerals, and fasces with double-bladed axes at the corner octagonal turrets. Amazingly, even larger ornamental pieces have been removed from the building. The 26-foot tall statuary groups at the 39th floor on the four sides of the building, each depicting a man embracing children, and eagles perched at the 34th floor at each corner are no longer in place. The ornamental terra cotta was created by Chicago sculptor Fritz Albert, the chief modeler of the Northwestern Terra Cotta Company.
Vertical Access technicians had the opportunity to see some of these faces of the LeVeque Tower up close when we inspected the exterior masonry of the building during the first week of April, 2012. VA’s investigation is part of the restoration of the building that has been a landmark on the Columbus skyline since it was completed in 1927. Designed by the noted theater architect C. Howard Crane, the 48-story LeVeque Tower rises over 555 feet into the air, taller than the Washington Monument and the tallest building between New York and Chicago when it was constructed for the American Insurance Union.
After the American Insurance Union went bankrupt, the “AIU Citadel” was purchased by John Lincoln and Leslie LeVeque in 1945 and became known as the Lincoln-LeVeque Tower. After 1977, the building was officially renamed the LeVeque Tower, with the LeVeque family retaining ownership until 2004. Between 2004 and 2011, the building changed hands multiple times. In 2011, the building was acquired by an investment group led by Robert Meyers of Tower 10 LLC, who is leading the effort to restore the landmark structure. Columbus design firm Schooley Caldwell Associates, Turner Construction Company, Chicago-based Berglund Construction are the principal parties involved with the restoration.
Slideshow: Workers rappel down LeVeque to examine exterior
These building inspectors climb LeVeque’s exterior
By Steve Wartenberg, The Columbus Dispatch Friday April 6, 2012 5:17 AM
Whenever she tells people that she makes a living climbing up and down buildings, doing inspections, Kelly Streeter gets one of three responses.
“Some people ask if I’m scared, others say there’s no way they would ever do that, and some people say it sounds like the best job ever,” she said of her career as an industrial rope-access technician.
Since Monday, Streeter and a small, well-trained team of safety-conscious climbers from Vertical Access have been Spider-manning their way up and down the 555-foot-6-inch-tall LeVeque Tower.
In exhausting six-hour shifts, they’ve rappelled down 600-foot ropes, toting 30 to 40 pounds of equipment that includes a self-braking descender with an anti-panic function to prevent free falls, a tablet computer to digitally log all the cracks and crumbles they spot — and snacks. READ FULL ARTICLE: These building inspectors climb LeVeque’s exterior | The Columbus Dispatch.
The Quarterly – January 2012
Read the January 2012 Quarterly Newsletter here. Subscribe to the blog and receive email updates automatically when news about what we’re doing is posted here throughout the year.
Update: New Jersey Considering Facade Legislation
In May 2011, we reported that the New Jersey Legislature was considering a statewide facade inspection program, bills S-2771/A-3895. The bills passed the Legislature last December, but were recently vetoed by New Jersey Governor Chris Christie. One reason cited by opponents of the legislation is that it would have given jurisdiction for the facade inspections to multiple local enforcement bodies. Opponents also argued that the state-wide ordinance would have duplicated facade inspection requirements that are already in place in New Jersey. Although the latter argument may be true for some building types, such as hotels and rental apartments, other types of high-rise buildings would have been brought into the periodic inspection process. In addition, the current New Jersey Hotel and Multiple Dwelling Act simply states that these properties must be inspected every five years, but does not specify the level of inspection. The proposed facade inspection program, which was based on Philadelphia’s 2010 facade ordinance, would have strengthened, clarified and standardized facade inspections in the state.
Vertical Access Documents Toronto’s Heritage
In the heart of the Toronto financial district is 1 King Street West, a hotel and residential tower that exemplifies both Toronto’s architectural heritage as well as the city’s more recent building boom. The current building on the eastern portion of the site was built in 1914 as the headquarters of The Dominion Bank. The 14-story masonry building has a granite base and terra cotta at the upper floors, with neo-classical ornament fitting for a bank building of the period. In 2005, a 51-story residential tower was appended to the historic building, making it one of the tallest residential buildings in Toronto.
[slideshow]
Continue reading Vertical Access Documents Toronto’s Heritage →