Hail Damage to Gutters – Repair or Replace?

I recently received an inquiry from a homeowner who, following a recent hail storm, had his gutters damaged.  He asked if he should seek to have his insurer pay to have them painted or replaced.

Although aluminum gutters can be repainted, this will become a process that will have to be repeated again and again over a period of time.  Even while the original surface will change color or become dull over time, the original surface is baked on and will not peel or crack, as will paint.  Painting gutters are, over time, the most expensive and least effective option.

This also applies to a metal siding.

A home owner’s insurance policy entitles that the home is restored as close as possible to the condition that it was prior to the loss event.  Painting a gutter or metal siding does not accomplish this.  Replacing it does.Damaged Gutter

Copyright 2013 James H. Bushart

http://www.publicadjustermissouri.com

 

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

Engineered Wood Flooring

Engineered wood flooring is an alternative to solid hardwood flooring made entirely out of real wood.  It’s currently the most popular type of flooring in the world.  North America is the only area left where traditional, solid wood floors still outnumber engineered floors, but engineered wood flooring is quickly catching up, with the rate of use for new builds, as well as remodels, increasing steadily every year for the past few decades.  Inspectors and homeowners alike may be interested in how this product is manufactured and installed, and what its advantages are compared to older, more traditional forms of flooring.

Brief History

The beginnings of mass-produced wood flooring can be dated as far back as 1903, when an E. L. Roberts mail-order catalog offered “wood carpeting.”  This flooring consisted of 1½ x 5/16-inch wooden strips that were glued to heavy canvas that was then installed by tacking it down with brads.  The wood was then sanded and finished.  The varnishes used were usually slow-curing tung oils from China.  These were not durable in themselves, so the floors were hot-waxed and buffed to a shine with a floor brush.

Early examples of the “wood carpet” eventually evolved into more modern iterations, such as laminate flooring, which consists of melamine-infused paper as its upper layer, and wood-chip composite beneath.  Laminate flooring typically features a printed or embossed top layer meant to approximate the look of real hardwood.

The current incarnation of engineered wood flooring has been available since the 1960s, and has steadily increased in quality, leading to improved advantages over traditional hardwood flooring.

Composition

Engineered wood flooring is most commonly made with a plywood-core substrate and a real hardwood veneer or skin, which comes pre-finished from the factory.  The top veneer, which looks just like the top of a traditional solid wood plank, is called the lamella. 

Some engineered flooring utilizes a finger-core construction, with a substrate comprised of small pieces of milled timber running perpendicular to the lamella.  This can be made with an additional layer of plywood running parallel to the lamella, which gives it added stability.  Fiberboard-core flooring is also available, but it’s generally considered to be an inferior option.

Engineered wood flooring is meant to be indistinguishable from traditional hardwood floor once it’s installed, and only the lamella is visible.  The lamella veneers available are made from nearly every type of common wood, as well as many more exotic ones, in order to provide the same variety of aesthetics typical of quality hardwood floors.  The substrate that the veneer is attached to is just as strong and durable as hardwood — if not stronger — and the finish applied at the factory often outlasts one applied on-site to solid wood flooring.  Even surface effects are available that can be applied to the finish to give the flooring a time-worn look, such as light distressing.

Engineered flooring runs the gamut from the low end, starting at $3 per square foot, to the high, at $14 and more. To judge quality, check the thickness of the lamella, the number of layers in the substrate, and the number of finish coats.  Typically, the more layers, the better. Listed below are descriptions of the advantages of adding layers to the construction in the common classes of engineered boards:

  • 3-ply construction: 1- to 2-mm wear layer; five finish coats; 10- to 15-year warranty; 1⁄4-inch thick; current price is about $3 to $5 per square foot.  Options for lamella veneer are limited to common species, such as oak and ash, and just a few stains are available;
  • 5-ply construction: 2- to 3-mm wear layer; seven finish coats; 15- to 25-year warranty; 1⁄4-inch thick; about $6 to $9 per square foot.  More species, such as cherry, beech, and some exotics are available for lamella, as well as all stains, and a few surface effects, such as distressing; and
  • 7-ply or more: 3+-mm wear layer, which can be sanded two or more times; nine finish coats; 25+-year warranty; 5/8- to 3⁄4-inch thick; average price is about $10 to $14 per square foot.  The widest selection of species is available for lamella, including reclaimed options.  More surface treatments are also available, such as hand-scraped and wire-brushed.

The cost of engineered flooring can be around 20% more than that of traditional flooring, but the difference can be offset or recouped by saving on installation, staining and sealing.

Installation

Installation of engineered wood flooring is generally quite simple compared to the installation of traditional hardwood, and can often be accomplished by a homeowner without the help of a professional flooring contractor.  If the services of a professional are enlisted, the job can be done more quickly and cost-effectively than if solid hardwood were to be installed.  Engineered flooring can be fastened in place with screws or nails, glued down, or left to “float,” relying on its mass to hold it in place.  Listed below are several installation methods:

  • A bead of glue can be applied to the tongue of each board, which is then tapped into place with a block. The floor floats, unattached to the sub-floor except by force of gravity.
  • A floor stapler and compressor can be used to rapidly secure the boards to the existing floor, without having to deal with any glue.
  • Boards can be laid in a bed of adhesive, as is done with tile.  This approach works particularly well over cured concrete, which precludes the use of staples.
  • Some types of engineered floor are designed with milled tongues and grooves that lock together without glue or fasteners. It’s the quickest and cleanest installation method.

Advantages of Engineered Flooring

While solid hardwood is a great traditional building material that provides aesthetically pleasing and structurally sound flooring, it does have its limitations.  For example, it cannot be installed directly on concrete or below grade, such as in basements.  It is generally limited in plank width and is more prone to gapping, which is excessive space between planks, and cupping, which is a concave or “dished” appearance of the plank, with the height of the plank along its longer edges being higher than the center with increased plank size.  Solid hardwood also cannot be used where radiant-floor heating is in place.
Engineered wood flooring, on the other hand, can actually provide some distinct advantages over traditional hardwood in many instances and applications.  Some of these include:
  • Lamella veneer is available in dozens of wood species.
  • Surface effects can be applied to further enhance its appearance.
  • The factory finish can outlast site-applied finish on solid hardwoods.
  • Drying time for the finish is eliminated because it’s pre-applied at the factory.
  • It can be used in basements and over concrete slabs.
  • Installation is quick and easy.
  • It can be used over radiant-heat systems.
  • It can be refinished to repair normal wear and tear.
  • The core layer can expand and contract more freely without warping.
  • The flooring can be removed and re-installed elsewhere, if desired.
Engineered wood flooring is increasingly the first choice for floor installations, and its advantages, in many circumstances, can be exceptional.  Homeowners with a little DIY experience can usually install it themselves.
by Nick Gromicko and Ethan Ward

Carpet Mold: Identification, Prevention and Removal

The Dangers of Mold

Molds produce allergens, which are substances that can cause allergic reactions, as well as irritants and, in some cases, potentially toxic substances known as mycotoxins.  Inhaling or touching mold or mold spores may cause allergic reactions in sensitive individuals.  Allergic responses include hay fever-type symptoms, such as sneezing, runny nose, red eyes, and skin rash (dermatitis).  Allergic reactions to mold are common.  They can be immediate or delayed.  Molds can also cause asthma attacks in people with asthma who are allergic to mold.  In addition, mold exposure can irritate the eyes, skin, nose, throat and lungs of both mold-allergic and non-allergic people.  Symptoms other than the allergic and irritant types are not commonly reported as a result of inhaling mold, but can also occur.

Carpet at Risk

Carpeting is an area of the home that can be at high risk for mold growth.  In order to grow, mold needs moisture, oxygen, a food source, and a surface to grow on.  Mold spores are commonly found naturally in the air.  If spores land on a wet or damp spot indoors that contains dust for them to feed on, mold growth will soon follow. Wall-to-wall carpeting, as well as area rugs, can provide an ample breeding ground for mold if conditions are right.  At especially high risk for mold growth are carpeting located below ground level in basements, carpet in commonly moist or damp climates, and carpet that has been wet for any period of time.

Identifying Mold in Carpeting

Just because mold is not immediately apparent or visible on a carpet’s surface does not mean that mold growth is not in progress.  In fact, mold will probably only be visible on the surface of carpets in unusually severe cases of growth, such as carpet damaged in flooding that has remained wet for some time.  The following are some examples of identifiable instances where mold growth has occurred or is likely to occur:

  • visible mold growth:  As stated above, this can be a rare case, but sometimes it may be obvious from visual inspection that mold growth is occurring.  Carpet in this condition is most likely not salvageable and should be disposed of and replaced.  Often, even if mold growth is not visible on the top of carpeting, it may be occurring underneath the carpet where it can’t be easily seen.  Carpet suspected of containing mold should always be examined on both sides.
  • carpet mildew:  Any discoloration or odor on carpeting that might be described as mildew is probably a case of mold.
  • wet or water-damaged carpet:  Any carpet that has been subjected to water damage from flooding or standing water will most likely need to be disposed of.  Conditions are ripe for mold growth, in this case.  Even if visibly apparent mold growth has not yet begun, it is highly likely to happen unless the carpet is completely removed, cleaned and dried within 24 to 48 hours.  Even then, removal and cleaning are not guaranteed to prevent mold growth.  It is more likely that the carpet will need to be replaced.
  • wet padding beneath carpet:  If padding beneath the carpet has become wet for any reason, or has become moist from condensation, the padding as well as the carpet on top are at risk for mold growth.  The padding may need to be replaced, as will the carpet, in some cases.
  • basement carpet:  Carpeting in basements below grade level is especially at risk in areas where humidity is high, or where wide temperature swings can produce condensation.
  • odors and stains:  There is a wide range of things that can cause odors and stains on carpets.  If mold is suspected, samples can be taken and sent for analysis to determine if mold growth has occurred.

Preventing Mold Growth in Carpeting

The best method for combating mold is to not allow mold growth in the first place.  The best way to do so is by ensuring that conditions conducive to growth do not exist.  Below are some ways to prevent mold growth in carpets.

  • Reduce indoor humidity.  The use of dehumidifiers will help control moisture in the air, depriving mold spores of the water they need to grow into mold.  A range of 30% to 60% humidity is acceptable for interiors.
  • Install intelligently.  Do not install carpeting in areas that are likely to be subject to frequent, high moisture.  Carpet in a bathroom, for example, will quickly turn to a breeding ground for mold growth due to the high humidity from constant water use in that area.
  • Choose high-quality carpet padding.  Solid, rubber-slab carpet padding with anti-microbial properties is available.  It is slightly more expensive than other types of padding but can be helpful for preventing the growth of mold, especially in climates prone to periods of high humidity.
  • Never allow standing water.  Carpet exposed to standing water will quickly be ruined.  If standing water ever occurs because of a leak or a spill, all carpeting exposed must be immediately cleaned and dried.  The top and bottom surfaces of the carpet, any padding, and the floor underneath must be cleaned and completely dried within a short period of time after exposure to standing water if the carpet is to be saved.  If a large flood has occurred, or if standing water has been present for any extended period of time, the carpet will probably need to be replaced.
  • Clean smart.  When carpeting needs to be cleaned, try to use a dry form of cleaning, when possible.  If any water, liquid, or other moisture has come in contact with the carpet during cleaning, be sure it is dried thoroughly afterward.

Removing Mold From Carpet

In many cases, if mold has grown on carpet, cleaning will not be possible.  If growth has occurred on more than one area of the carpet, or if there is a large area of growth, the carpet will probably need to be replaced. 

Small areas of growth that have been quickly identified can sometimes be dealt with.  Detergent and water used with a steam-cleaning machine may be enough to clean the carpet thoroughly.  It is then important to ensure that the carpet dries completely after cleaning to prevent the growth from recurring.  Stronger cleaning agents can be substituted if detergent does not work.  Anything stronger than detergent or common rug-cleaning products should first be tested on an inconspicuous area of the carpet to ensure that the rug will not be damaged during cleaning.  About 24 hours is a reasonable amount of time to wait after testing to be sure that wider cleaning will not discolor or damage the carpet.

Another option in instances where mold growth is not widespread is to remove the ruined section of the carpet.  If cleaning has been attempted unsuccessfully, the area of mold growth may be removed and replaced with a patch of similar carpet.  Of course, this will only work in situations where aesthetics are not a big concern, since exactly matching the patch to the original carpet may be difficult and the seam may be visible.  If mold has grown in more than one area of the carpet, or if the area of growth is larger than a couple of feet, this will probably not be an effective method of mold removal.
As with all areas of the interior at risk for mold growth, prevention is the best method of control for carpet mold.  Eliminating high-moisture conditions and preventing the risk of flooding or standing water will reduce the possibility of growth.  Inspectors will want to know where to look for and how to identify mold growth in carpeting.  It is also helpful to know how to determine if carpet should be replaced, or whether there is a possibility of cleaning and saving it.
by Nick Gromicko and Ethan Ward

Insurance Claims for Hail Damage

By James H. Bushart

 

Hail damage to a roof is a common occurrence and damage is often and routinely repaired at the expense of insurance companies.

For some insurance adjusters delaying, denying and defending a claim is also routine and are the three main strategies used to promote the financial interests of the insurance carrier at the expense of the insured.

As a part of this strategy when delaying, denying or defending a claim filed for hail damage to a roof, many claims adjusters (after making their own inspection and declaring that there is no damage to the roof) will arrange to provide an insured homeowner with a “special service” by having an engineer evaluate the roof for damage, as well.

Evaluating the condition of a roof covering does not require an engineering background, but it does impress many people to see an engineer’s seal and signature under an observation. While making an effort to appear to be objective, and while still fully aware that future referrals and fees are at stake, the hired engineer will sometimes seek ways to confirm the initial finding made by the adjuster.

Here is one of the methods used to minimize observed hail damage to a roof while appearing to be objective and “scientific”.

In spite of the damage that is visible to the naked eye many engineer reports that have been used by insurance companies to deny claims that I have personally read will refer to an opinion that a “rate of acceleration” and “velocity” of the hail strikes were insufficient to cause “significant” damage to the roof coverings.

Sounds like some real indisputable engineering stuff, doesn’t it?  At least, it does until one considers the following:

1.  The storm has passed by the time the adjuster and engineer have examined the roof.

2.  “Terminal velocity”, or the maximum speed reached by a falling object, is measured by a mathematical formula that takes into account the size of the hailstone and the high winds and gusts that can accelerate the speed of the hailstone.

3.  The actual size of each hailstone that struck the roof … and the speed of the wind and gusts that drove the hailstone into the roof … cannot be determined by simply looking at the roof days, weeks, months or years after a storm.

4.  Remarks that appear in the engineer’s report that address the sufficiency of the “velocity” or “rate of acceleration” to cause damage is pure speculation.  The fact that it is being “speculated” by an engineer does not make it more than speculation.  It is not factual.

The physical evidence of hail damage will speak for itself.  Speculations as to velocity and acceleration that are provided from observations made days, weeks or months after the event are not factual and should not be allowed to be used to deny a claim in the presence of actual damage.

If you find references to “velocity” and/or “rate of acceleration” in any engineer’s report that supports your insurance company’s denial of your claim for roof damage caused by hail, request in writing that you be provided with the factors and formula(s) used to calculate these rates.  Also, ask for the source of the data used to determine the size of the hailstones and the speed of the wind and gusts that drove the hailstones into your roof.

For more information about how some insurance companies use engineer reports to routinely deny valid claims, click on the following link and read:  https://missouripublicadjuster.org/2017/03/09/fraudulent-engineer-reports-and-your-homeowners-insurance-claim/

 

 

Copyright 2012 James H. Bushart

Abrasive Blasting for Mold Remediation

 Mold in the Home

Health concerns related to the growth of mold in the home have been featured heavily in the news.  Problems ranging from itchy eyes, coughing and sneezing to serious allergic reactions, asthma attacks, and even the possibility of permanent lung damage can all be caused by mold, which can be found growing in the home, given the right conditions.

All that is needed for mold to grow is moisture, oxygen, a food source, and a surface to grow on.  Mold spores are commonly found naturally in the air.  If spores land on a wet or damp spot indoors and begin growing, they will lead to problems.

Molds produce allergens, irritants and, in some cases, potentially toxic substances called mycotoxins.  Inhaling or touching mold or mold spores may cause allergic reactions in sensitive individuals.

Allergic responses include hay fever-type symptoms, such as sneezing, runny nose, red eyes, and skin rash (dermatitis).  Allergic reactions to mold are common.  They can be immediate or delayed.  Molds can also trigger asthma attacks in people with asthma who are allergic to mold.

In addition, mold exposure can irritate the eyes, skin, nose, throat and lungs of both mold-allergic and non-allergic people.

As more is understood about the health issues related to mold growth in interior environments, new methods for mold assessment and remediation are being put into practice.  Mold assessment and mold remediation are techniques used in occupational health.  Mold assessment is the process of identifying the location and extent of the mold hazard in a structure.

Mold remediation is the process of cleanup and/or removal of mold from an indoor environment.  Mold remediation is usually conducted by a company with experience in construction, demolition, cleaning, airborne-particle containment-control, and the use of special equipment to protect workers and building occupants from contaminated or irritating dust and organic debris.  A new method that is gaining traction in this area is abrasive blasting.

Abrasive Blasting

The first step in combating mold growth is not to allow for an environment that is conducive to its growth in the first place.  Controlling moisture and assuring that standing water from leaks or floods is eliminated are the most important places to start.  If mold growth has already begun, the mold must be removed completely, and any affected surfaces must be cleaned or repaired.

Traditional methods for remediation have been slow and tedious, often involving copious amounts of hand-scrubbing and sanding.  Abrasive blasting is a new technique that is proving to be less tedious and time-consuming, while maintaining a high level of effectiveness.

Abrasive blasting is a process for cleaning or finishing objects by using an air-blast or centrifugal wheel that throws abrasive particles against the surface of the work pieces. Sand, dry ice and corncobs are just some of the different types of media used in blasting.  For the purposes of mold remediation, sodium bicarbonate (baking soda) and dry ice are the media commonly used.

Benefits of Abrasive Blasting

Abrasive (or “media”) blasting provides some distinct advantages over traditional techniques of mold remediation.  In addition to eliminating much of the tedious labor involved in scrubbing and sanding by hand, abrasive blasting is extremely useful for cleaning irregular and hard-to-reach surfaces.

Surfaces that have cross-bracing or bridging can be cleaned more easily, as well as areas such as the bottom of a deck, where nails may be protruding.  Areas that are difficult to access, such as attics and crawlspaces, can also be cleaned more easily with abrasive blasting than by traditional methods.

The time saved is also an advantage, and the typical timeframe for completion of a mold remediation project can often be greatly reduced by utilizing abrasive blasting.

Soda-Blasting

Soda-blasting is a type of abrasive blasting that utilizes sodium bicarbonate as the medium propelled by compressed air.  One of the earliest and most widely publicized uses of soda-blasting was on the restoration of the Statue of Liberty.
In May of 1982, President Ronald Reagan appointed Lee Iacocca to head up a private-sector effort for the project.  Fundraising began for the $87 million restoration under a public-private partnership between the National Park Service and The Statue of Liberty-Ellis Island Foundation, Inc.  After extensive work that included the use of soda-blasting, the restored monument re-opened to the public on July 5, 1986, during Liberty Weekend, which celebrated the statue’s  centennial.

The baking soda used in soda-blasting is soft but angular, appearing knife-like under a microscope.  The crystals are manufactured in state-of-the-art facilities to ensure that the right size and shape are consistently produced.

Baking soda is water-soluble, with a pH near neutral. Baking-soda abrasive blasting effectively removes mold while minimizing damage to the underlying surface (i.e., wood, PVC, modern wiring, ductwork, etc.).  When using the proper equipment setup (correct nozzles, media regulators, hoses, etc.) and technique (proper air flow, pressure, angle of attack, etc.), the process allows for fast and efficient removal of mold, with a minimum of damage, waste and cleanup.  By using a soda blaster with the correct-size nozzle, the amount of baking soda used is minimized. Minimal baking soda means better visibility while working, and less cleanup afterward.

Dry-Ice Blasting

Dry ice is solidified carbon dioxide that, at -78.5° C and ambient pressure, changes directly into a gas as it absorbs heat.  Dry ice pellets are made by taking liquid carbon dioxide (CO2) from a pressurized storage tank and expanding it at ambient pressure to produce snow.  The snow is then compressed through a die to make hard pellets.  The pellets are readily available from most dry ice suppliers nationwide.  For dry-ice blasting, the standard size used is 1/8-inch, high-density dry ice pellets.

The dry-ice blasting process includes three phases, the first of which is energy transfer.  Energy transfer works when dry ice pellets are propelled out of the blasting gun at supersonic speed and impact the surface. The energy transfer helps to knock mold off the surface being cleaned, with little or no damage.

The freezing effect of the dry ice pellets hitting the mold creates the second phase, which is micro-thermal shock, caused by the dry ice’s temperature of -79º C, between the mold and the contaminated surface.  This phase isn’t as much a factor in the removal of mold as it is for removing resins, oils, waxes, food particles, and other contaminants and debris.  For these types of substances, the thermal shock causes cracking and delaminating of the contaminant, furthering the elimination process.

The final phase is gas pressure, which happens when the dry ice pellets explode on impact.  As the pellets warm, they convert to CO2 gas, generating a volume expansion of 400 to 800 times.  The rapid gas expansion underneath the mold forces it off the surface.

HEPA Vacuuming

A HEPA vacuum is a vacuum cleaner with a high-efficiency particulate air (or HEPA) filter through which the contaminated air flows.  HEPA filters, as defined by the U.S. Department of Energy’s standard adopted by most American industries, remove at least 99.97% of airborne particles that are as small as 0.3 micrometers (µm) in diameter.  HEPA vacuuming is necessary in conjunction with blasting for complete mold removal.

While abrasive blasting with either baking soda or dry ice is an effective technique, remediation will not be complete until HEPA filtering or vacuuming has been done.  Abrasive blasting removes mold from contaminated surfaces, but it also causes the mold spores to become airborne again.  The spores can cover the ground and the surfaces that have already been cleaned.  So, the mold spores need to be removed by HEPA filters.

Additionally, while some remediation companies claim that there will be no blasting media to remove after cleaning, especially with the dry-ice method, there will be at least a small amount of visible debris left by the blasting that must be removed before HEPA vacuuming can occur.  HEPA vacuuming removes all invisible contaminants from surfaces and the surrounding air.  When HEPA vacuuming is completed, samples at the previously contaminated areas should be re-tested to ensure that no mold or mold spores remain.

by Nick Gromicko and Ethan Ward

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