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It must first be determined what constitutes the failure.

Once I was looking to build a wood floor that would finish to dark reddish brown. I chose Brazilian Walnut. To get added strength and resistance to indentations (high heel shoes, wheel marks), I chose wood that was quarter sawn. Little did I know that when this wood is quarter sawn it exposes a vain that when stained turns yellow. Some people think this beautiful (like Me). But, not the client I built this floor for. In their eyes the floor failed.

There was a lovely home built on the bluffs overlooking Malibu Beach. It had large glass doors the full width of the house facing southwest. The flooring contractor installed a solid oak plank floor in accordance with the industry standards. The floor cupped badly. The floor had failed. My investigation found that there was a 35º difference in the temperature of the room from ceiling to floor during the day. The sun was so strong that it was cooking the wood, causing it to expand.

As wood floor experts, it is not only our job to find out what went wrong, but, to predict what might go wrong in a future project.

Moisture vapor is the first suspect.

http://www.youtube.com/watch?v=GFhzFjtI2to

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What makes an expert credible to a jury? Clearly this is a critical question for both lawyers, and the expert witnesses they retain. The most knowledgeable expert in the world is functionally useless unless they can effectively communicate their expertise to a jury, something every lawyer knows well.

Kathy Kellerman, of ComCom, cites extensive jury research in her argument that good experts are “good teachers with sound credentials and acceptable motives for offering their testimony”.

This revealing article, based on post-case jury interviews, can be read in whole below.

“Experts are important witnesses in a high percentage of civil and criminal trials. Jurors use multiple criteria to judge the credibility of expert testimony.

Schuman and colleagues (1994) interviewed jurors from many different trials in a number of cities about how they responded to expert testimony. Jurors considered an expert’s (a) tendency to draw firm conclusions, (b) qualifications and reputation, (c) reasoning, (d) familiarity with the facts of the case, and (e) impartiality. Jurors did not rely on superficial characteristics such as appearance or personality, nor defer automatically to an expert’s conclusions.

Ivkovich and Hans (2003) interviewed 55 jurors who served in 7 different civil trials involving medical malpractice, workplace injury, product liability, asbestos, and a motor vehicle accident. The criteria jurors used to evaluate the expert testimony involved both the message and the messenger:

• Jurors evaluated the content of expert testimony by looking at its (a) completeness, (b) consistency with other evidence, and (c) complexity.
• Jurors evaluated the experts on the basis of (a) their credentials, (b) motives for their testimony, (c) general impressions, and (d) the content and presentation of their testimony. The importance of these factors varied from juror to juror, expert to expert, and case to case. Good witnesses were described as good teachers with sound credentials and acceptable motives for offering their testimony. Jurors agreed less about what made a bad witness.

In sum, jurors evaluate experts and their testimony on their merits”

As a member of the ASTM F-13 committee we keep up with current scientific standards that measure floor safety. The committee met in January and confirmed the F609-05 standard for measuring slip resistance. This standard is not to be used on contaminated floors, such as vinyl flooring, ceramic tile flooring, stone flooring, and rubber flooring.

“The Horizontal Pull Slipmeter3 is a laboratory and field instrument designed to provide information about the slip index characteristics between walkway surfaces and a test foot material under dry conditions only. The HPS can not be used on wet surfaces. Slip index can be affected by surface roughness, presence of water, contaminants such as grease and other foreign materials, and floor surface wear over time. Slip index, as determined by the HPS, most likely will not give useful information for evaluating liquid contaminated surfaces, and therefore, will not provide an effective assessment of a potential slipping hazard on a walkway surface under these conditions.

The value reported by the Horizontal Pull Slipmeter is called the slip index. Slip index is ten times the static coefficient of friction. For example, a static coefficient of friction of 0.4 is displayed by a slip index of 4.0 when measured by the Horizontal Pull Slipmeter.

The HPS can be used on inclined surfaces. No adjustment for slope is needed for measurements in the direction perpendicular to the slope and when averaging four measurements at one location taken according to step”.

We are involved in a sports and recreation center. There is Solid Maple, Vinyl Composite Tile, and Carpet on the floors. The site is 4 years old, but the building opened 8 months ago. The wood flooring is showing early signs of expansion, and the VCT is de-bonding.

The evidence is that moisture vapor intrusion has been deleterious to the final product. The documents showed that Calcium Chloride tests (ASTM F1869) were taken at appropriate times. The wood-flooring manufacturer accepted the CaCl results, and gave the go ahead with the installation.

There is a controversy in the floor covering industry as to the proper test protocol for the moisture condition of concrete. F1869, the Calcium Chloride (moisture Dome Test) or ASTM F2420, Relative humidity test (probe test). There is a place for both protocols.

The Forensic Flooring Expert must opine as to who is at fault. This opinion becomes more convoluted, when it is discovered that the design of the sub-structure is contra-indicated by the manufacturer of the floor covering. The industry standards were inadequate and did not prevent this outcome.

The Forensic Science surrounding Slip & Fall cases has dramatically changed. The science of slip resistance measurement in the field, has taken a dramatic turn.

As a member of ASTM International, we stay up on changes in scientific standards, as they pertain to the use of floors, and flooring materials. Since ASTM standards F1679 & F1677 were withdrawn, the weight of measuring slip resistance in the field has fallen on ASTM C1028.

ASTM C1028 is clear, the presence of contaminates on a floor surface must be considered, and identified, when using the results of a drag sled to issue an opinion on floor safety.

Oddly, the engineers using the above test methods, rarely, if ever, identify the presence of contaminates that are routinely weighted by a Floor Expert. Contaminates that are airborne, contaminates that are applied during maintenance, and contaminates that are a residue of common use are all suspect.

We have been successful in the discovery of contaminates that exist on the floors, previously considered safe. This will affect the outcome of slip & fall litigation.

Ken,

Shortly before the holidays, we replaced the 4 flights of failing stair treads with Nora Norament stair treads. Aside from a slight hiccup with post-installation cleaning which we resolved after the first day, the stairs are performing quite well after 6 weeks of use.

Thank you for your help with this. I am certain your presence and your guidance during negotiations enable the Medical Center to achieve the resolution of changing products at no cost to us aside from some general conditions expenses.

Katy Merwin, Director, PM Services
Office of Design & Construction
UCSF Medical Center

As wood flooring experts, we are involved in a wood flooring case that revolves around the degree of damage to a solid oak floor. Heavy furniture was rolled over the floor, without protection, leaving furrows in the surface. When is it too late to refinish the wood?

The investigation of a floor that is over 100 years old revealed that wood had been refinished once or twice in its lifetime. The average reduction of surface is 1/32 of an inch from refinishing. The Forensic study found that the oak flooring had lost 1/32 of an inch from previous repair work. A measurement of the damage showed the furrows to be 1/64 of an inch.

We recommended a refinish not a replacement.

Viewing “Sweep Sheets” is part of the forensic science of slip & fall in supermarkets. As slip & fall experts, we look at what makes a floor safe or unsafe.  We have handled investigations in Wal*Marts, Targets, Ralphs, Vons, Safeway, and others.

The traditional slip meter tests are no longer accepted as scientifically valid, we are floor experts, and look at the procedures the supermarket uses to maintain a safe floor. High gloss finishes do no mean the floor is unsafe. We know what to look for the finish or in the janitorial closet that can hurt a safe floor.

I was just deposed in a slip & fall case. The site was a restaurant floor. I discussed the presence of contaminants on a ceramic tile floor. There are differences in surface textures and how they combine with air-bourn heavy particulates. If a facility is near a heavily trafficked street or freeway, is likely that special precautions be taken when selection or maintaining ceramic tile. This because 80 percent of the air in a conditions space is from the outside, all exhaust fumes have heavy petro-carbon particulates that settle to the floor. As a floor expert have studied most of the conditions that affect the performance of a floor covering after it comes from the box.

In 2010, we handled failures of Rubber Flooring, Vinyl Composite Tile, Carpet, Wood Flooring, and Dimensional Stone. In each case there were expectations of material performance that did not match up to generally accepted norms. The carpet, that was used in a very high traffic location had too much yard, and compressed further then expected. The Rubber Flooring was not designed to the construction of the sub-floor.