How to Determine the Age of a Building

 

Building technologies and fashions have followed well-known trends that  allow those interested to roughly determine Crude, square nails may be hundreds of years oldwhen  particular buildings were constructed.  Here are some methods based on a  building’s materials, components and styles.
 
Estimates of Building Age Based on Building  Materials
 

Nails

  • Prior to the 1800s, nails were hand-made by blacksmiths and nail makers  and appear crude compared with modern nails. They are often squared rather than  rounded, and have a beaten look on the top of the head.
  • Type A- and Type B- cut nails were used from 1790 to 1830. They were  made from wrought iron and are squared.
  • Wire nails, used from 1890 through today, are modern, machine-made  nails that are rounded and more practical to use than the earlier designs.

Wiring

  • Aluminum wiring was used extensively from 1967 till 1975, a  period during which copper was prohibitively expensive. Aluminum use  was generally discontinued when its potential as a fire hazard become  publicized.
  • K&T or knob-and-tube wiring was an early method of electrical  wiring installed in buildings from 1880 to the 1940s. The system is considered  obsolete and can be a fire hazard, although much of the fear associated with it  is exaggerated.

Electrical ReceptaclesModern electrical receptacles are polarized and grounded

Electrical receptacles evolved from earliest to most recent in the following  order:

  • non-polarized:  These early receptacles are made up of two slots  of equal size, with no ground slot.
  • polarized:  These receptacles are two-slotted, one of which is wider  than the other to allow for proper polarity.
  • grounded, polarized:  Modern receptacles were changed to permit  grounding of an appliance or device. They can be identified by the round hole  beneath the center of the polarized slots.

Flooring

  • In the late 19th century (1890), linoleum became common for  use in hallways and passages, but it became better known for its use in kitchen  floors in the 20th century, up through 1960. Originally valued for  its water-resistance and affordability, it was surpassed by other floor  coverings by the mid-20th century.
  • Asphalt tile was used for floor tiles starting around 1920 through  the 1960s. The earliest tiles are darker because they contained more asphalt,  unlike later tiles that had higher levels of synthetic binders.Old linoleum floor
  • Vinyl asbestos tiles became popular in response to consumers who wanted  lighter-colored tiles of varying color patterns.

Structural Panels

  • Plywood’s use began around 1905.  It is made from thin sheets of veneer  (layers of wood that are peeled from a spinning log) that are cross-laminated  and glued together with a hot press. Since it is made from whole layers of logs  rather than small strands, plywood has a more consistent and less rough  appearance than oriented strand board (OSB).
  • Waferboard or particle board was developed in the 1970s and, like plywood,  is still used today. This material appears similar to OSB, except the wooden  strands from which it is composed are not aligned.
  • OSB was developed the 1980s and is manufactured from heat-cured  adhesives, and then rectangularly shaped wood strands that are arranged in  cross-oriented layers. Produced in large, continuous mats, OSB is a solid-panel  product of consistent quality with few voids and gaps. While OSB was  developed fairly receDutch-style Colonial housently,  it became more popular than plywood in North America by 2000.

Keep in  mind that houses, especially older ones, have evolved over many years. It can be  very difficult to reliably date a building based on the presence of a single  material or component. The majority of a house might be newer than its  18th century foundation, for instance, especially if there was a fire  that destroyed the rest of the structure.

Estimates of Building Age Based on Architectural Style 
  • American Colonial (1600 to 1800):  North America was colonized by  Europeans who brought with them building styles from their homelands. This broad  category includes the following regional styles and their characteristics:
    • New England style (1600 to 1740):  These homes feature steep roofs  and narrows eaves used in simple timber-frame houses, usually located in  the northeastern United States, primarily in Massachusetts, Vermont,  Connecticut, New Hampshire and New York.
    • German (1600 to 1850):  Most often found in New York,  Pennsylvania, Ohio and Maryland, these buildings generally feature thick,  sandstone walls.
    • Spanish (1600 to 1900):  Located in the American South, Southwest,  and California, these houses are simple and low, built from rocks, stucco,  coquina and adobe brick, with small windows and thick walls.
    • Other home styles from the American Colonial period include Georgian,  Dutch, French and Cape Cod.
  • Classical style houses (1780 to 1860):  Many houses built during  the founding of the United States are a throwback to ancient Greece, emphasizing  order and symmetry. Among the styles common to this era are Greek Revival,  Tidewater and Antebellum.
  • Victorian (1840 to 1900): With the technological innovation  of mass production came the ability to produce large homes affordably.  Queen Anne, Gothic Revival, Folk and Octagon are some of the architectural  styles common to this era.
  • Gilded Age (1880 to 1929): The “Gilded Age” is a term popularized by Mark  Twain to describe extravagant wealth. This era saw the construction of large,  Mcmansions are hastily-built and often too large for their plot of landelaborate homes owned  by a class of suddenly-rich businessmen who enjoyed grandiose displays of their  new wealth.
  • Early 20th Century homes:  Homes built during this period  were compact and economical, somewhat smaller and less pretentious than earlier  Gilded Age homes.
  • Post-War homes (1945 to 1980):  Very simple and affordable, some  critics believe they have no style at all. Soldiers returning from the World War  II spurred the construction of these homes, which emphasized utilitarianism  over style more than preceding periods.
  • “Neo” houses (1965 to present):  Theses houses borrow styles from  previous architectural eras, such as Victorian, Colonial and Mediterranean.  “McMansion” is a word used to describe large, quickly-constructed, flamboyant  and poorly-designed neo-eclectic homes.

Other Ways to Determine a Building’s Age:

  • Check the meter reader. Sometimes, the meter reader will bear a date stamp.
  • Check the inside of the toilet. Toilet manufacturers often stamp the inside  of tanks or lids with the year the toilet was made. Toilets are usually  installed right after construction, so you can often determine a newer home’s  age by inspecting a toilet.
  • In log homes, it may be possible to tell the building’s age by analyzing the  tree rings in a piece of timber removed from the building. The science on which  this is based, dendrochronology, does not arrive at an age based on the number  of tree rings, but rather focuses on patterns of tree rings and compares these  with known pattern ages for a specific region. This method is destructive and it  requires a specialist.
  • Local town, county, or state tax records usually indicate the date or  year a building was constructed.
  • Historical real estate listings may include indications of building age.
  • Census records can prove that a house was present at the time the census was  taken.
  • Papers found inside the building will often indicate when the building was  present. A house will probably be at least as old as, for instance, newspapers  from the 1920s found in a crawlspace.
  • Employ an architectural investigator to date the house by studying its wood,  plaster, mortar and paint.
  • The aluminum spacers within thermal-paned windows often bear the year of  production, which can at least provide an approximate date of  installation.
  • Sewer grates are sometimes stamped with the year they were manufactured,  which may provide an age for the neighborhood.

by Nick Gromicko

www.publicadjustermissouri.com

Aluminum Electrical Wiring

Between approximately 1965 and 1973, single-strand aluminum wiring was sometimes substituted for copper branch-circuit wiring in residential electrical systemsAluminum and copper wiring, with each metal clearly identifiable by its color due to the sudden escalating price of copper. After a decade of use by homeowners and electricians, inherent weaknesses were discovered in the metal that lead to its disuse as a branch wiring material.
Although properly maintained aluminum wiring is acceptable, aluminum will generally become defective faster than copper due to certain qualities inherent in the metal. Neglected connections in outlets, switches and light fixtures containing aluminum wiring become increasingly dangerous over time. Poor connections cause wiring to overheat, creating a potential fire hazard.
In addition, the presence of single-strand aluminum wiring may interfere with a home’s insurance coverage. Home owners are advised to talk with their insurance agents about whether the presence of aluminum wiring in their home is a problem that requires changes to their policy language.
Facts and Figures
  • On April, 28, 1974, two people were killed in a house fire in Hampton Bays, New York. Fire officials determined that the fire was caused by a faulty aluminum wire connection at an outlet.
  • According to the Consumer Product Safety Commission (CPSC), “Homes wired with aluminum wire manufactured before 1972 [‘old technology’ aluminum wire] are 55 times more likely to have one or more connections reach “Fire Hazard Conditions” than is a home wired with copper.”
Aluminum as a Metal

Aluminum possesses certain qualities that, compared with copper, make it an undesirable material as an electrical conductor. These qualities all lead to loose connections, where fire hazards become likely. These qualities are as follows:

  • higher electrical resistance. Aluminum has a high resistance to electrical current flow, which means that, given the same amperage, aluminum conductors must be of a larger diameter than would be required by copper conductors.
  • less ductile. Aluminum will fatigue and break down more readily when subjected to bending and other forms of abuse than copper, which is more ductile. Fatigue will cause the wire to break down internally and will increasingly resist electrical current, leading to a buildup of excessive heat.
  • galvanic corrosion.  In the presence of moisture, aluminum will undergo galvanic corrosion when it comes into contact with certain dissimilar metals.
  • oxidation. Exposure to oxygen in the air causes deterioration to the outer surface of the wire. This process is called oxidation. Aluminum wire is more easily oxidized than copper wire, and the compound formed by this process – aluminum oxide – is less conductive than copper oxide. As time passes, oxidation can deteriorate connections and present a fire hazard.
  • greater malleability. Aluminum is soft and malleable, meaning it is highly sensitive to compression. After a screw has been over-tightened on aluminum wiring, for instance, the wire will continue to deform or “flow” even after the tightening has ceased. This deformation will create a loose connection and increase electrical resistance in that location.
  • greater thermal expansion and contraction. Even more than copper, aluminum expands and contracts with changes in temperature. Over time, this process will cause connections between the wire and the device to degrade. For this reason, aluminum wires should never be inserted into the “stab,” “bayonet” or “push-in” type terminations found on the back of many light switches and outlets.
  • excessive vibration. Electrical current vibrates as it passes through wiring. This vibration is more extreme in aluminum than it is in copper, and, as time passes, it can cause connections to loosen.

Identifying Aluminum Wiring

  • Aluminum wires are the color of aluminum and are easily discernible from copper and other metals.
  • Since the early 1970s, wiring-device binding terminals for use with aluminum wire have been marked CO/ALR, which stands for “copper/aluminum revised.”
  • Look for the word “aluminum” or the initials “AL” on the plastic wire jacket. Where wiring is visible, such as in the attic or electrical panel, inspectors can look for printed or embossed letters on the plastic wire jacket. Aluminum wire may have the word “aluminum,” or a specific brand name, such as “Kaiser Aluminum,” marked on the wire jacket. Where labels are hard to read, a light can be shined along the length of the wire.
  • When was the house built? Homes built or expanded between 1965 and 1973 are more likely to have aluminum wiring than houses built before or after those years.

Options for Correction

Aluminum wiring should be evaluated by a qualified electrician who is experienced in evaluating and correcting aluminum wiring problems. Not all licensed electricians are properly trained to deal with defective aluminum wiring. The CPSC recommends the following two methods for correction for aluminum wiring:

  • Rewire the home with copper wire. While this is the most effective method, rewiring is expensive and impractical, in most cases.
  • Use copalum crimps. The crimp connector repair consists of attaching a piece of copper wire to the existing aluminum wire branch circuit with a specially designed metal sleeve and powered crimping tool. This special connector can be properly installed only with the matching AMP tool. An insulating sleeve is placed around the crimp connector to complete the repair. Although effective, they are expensive (typically around $50 per outlet, switch or light fixture).

Although not recommended by the CPSC as methods of permanent repair for defective aluminum wiring, the following methods may be considered:

  • application of anti-oxidant paste. This method can be used for wires that are multi-stranded or wires that are too large to be effectively crimped.
  • pigtailing. This method involves attaching a short piece of copper wire to the aluminum wire with a twist-on connector. the copper wire is connected to the switch, wall outlet or other termination device. This method is only effective if the connections between the aluminum wires and the copper pigtails are extremely reliable. Pigtailing with some types of connectors, even though Underwriters Laboratories might presently list them for the application, can lead to increasing the hazard. Also, beware that pigtailing will increase the number of connections, all of which must be maintained. Aluminum Wiring Repair (AWR), Inc., of Aurora, Colorado, advises that pigtailing can be useful as a temporary repair or in isolated applications, such as the installation of a ceiling fan.
  • CO/ALR connections. According to the CPSC, these devices cannot be used for all parts of the wiring system, such as ceiling-mounted light fixtures or permanently wired appliances and, as such, CO/ALR connections cannot constitute a complete repair. Also, according to AWR, these connections often loosen over time.
  • alumiconn. Although AWR believes this method may be an effective temporary fix, they are wary that it has little history, and that they are larger than copper crimps and are often incorrectly applied.
  • Replace certain failure-prone types of devices and connections with others that are more compatible with aluminum wire.
  • Remove the ignitable materials from the vicinity of the connections.

In summary, aluminum wiring can be a fire hazard due to inherent qualities of the metal.

by Nick Gromicko, Rob London and Kenton Shepard

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