Safety Glass

Last year, the Home Inspector Licensing Advisory Board for the state of Washington attempted to upgrade the Standards of Practice. Early this year, the inspector community had their chance to respond, and they showed up at the rules hearing in Olympia - and they brought their pitchforks.

I was actually happy to see them as I think that the inspectors tend towards apathy most of the time. All of the proposed changes had been discussed at multiple meetings previously, on both sides of the state, but until the rules came down, no one seem to care. As a Board member, I had no role at the rules meeting, but I - along with most of the other Board members - to hear from our fellow inspectors.

One of the proposed rules, and the second most contested, was about safety glazing. Watch any cop show and at some point somebody is going to collide with a windshield, leaving that distinctive spider-web of crazing on the glass.

That's safety glazing (safety glass) in action. Safety glazing is used to make the failure of the glass when it fractures less hazardous by minimizing the dagger-like shards that typical untreated glass crystal forms.

Two arguments were offered in opposition. The first was that identifying safety glass is outside the scope of every single Standard of Practice. This statement is truthful but incomplete. ASHI doesn't include it in their Standard of Practice, but then has an article on "Six Things Your Home Inspector Will Look For." There is a lot of good information in the article, but this quote was most interesting in light of the discussion we are having in Washington State.

"Safety should always be primary to the home inspector -- always," says Troy Bloxom, president of the National Association of Home Inspectors and owner of Home Inspections Plus near Anchorage, Alaska. . . . . Safety glass: Are the glass features installed near stairs or water (like tubs and showers), made of safety (or "tempered") glass?

InterNACHI doesn't have it in their standard, either - but has an article to train inspectors to identify it.

The second point against it was how many people really get hurt because of a glazing failure. Do we really have a problem that needs fixing?

Safety glass first entered the codes in the mid-1960s as a result of numerous lawsuits against glass manufacturers. By 1966, a working standard was developed and the Glazing Industry Code Committee pushed hard for its adoption nation-wide. A great discussion on this and a detailed look at safety glazing can be found in Doug Hansen's article Safety Glazing, published by . . . ASHI.

The short version is that the glazing industry successfully lobbied for safety glass. It's been in the codes for the better part of four decades and predates such safety devices as GFCI receptacles.

Yet, while the Ground Fault Circuit Interrupter is an item in all the inspector Standards of Practice, the more venerable safety glazing gets ignored. Using the data from, we can get some numbers. 2010 is the last year that I could get data, so we'll use that for our baseline.

In 2010, the data indicates there were 2637 injuries that required emergency treatment - for electrical shocks. This almost certainly underreports the incidence rate of shock and probably the rate of physical injury (burns, mostly.) So let's take that number and quadruple it, to 10,000 events.

The number for window injuries? 110,322. In one year, 2010. Now, a caveat. Where the electrical data understates the rate, this number greatly overstates the injury rate that we can attribute to glazing failures. I had to dig into the numbers, looking at each case to find those that could reasonably fit my criteria. "PT {patient} WAS PLAYING WHEN A WINDOW FELL AND SHUT ON PTS LEFT HAND. D: CLOSED NONDISPLSACED FX OF LEFT HAND" clearly is a different problem, and not a result of the glass shattering.

On the other hand, so to speak, we have "13 YO M, C/O CUT TO RT 2ND AND 3RD FINGER AFTER PUNCHING A WINDOW B/C M OTHER WOULD NOT ALLOW HIM TO USE COMPUTER, DX FINGER LACERATION." We can't know whether or not the window this teen punched was safety glass protected. We can say that if it was, the injury was probably far less than he would have otherwise suffered.

In all, about a third of the incidents mentioning windows involved breakage. So, in a single year, the injuries resulting from glass was three times higher than our inflated rate of shock from receptacles.

So why are GFCI's a mandatory part of inspector standards and not safety glass? In a word, liability. The GFCI is easy to spot. Safety glass? Not so much, especially older pieces. Nowadays, we mark the glass which makes it a bit easier to identify. That wasn't the case in the 1970s and 1980s. Guessing about those glass panels is a guessing game. While there are tests we can perform with polarized lens and light, they are not practical for working in the field as an inspector.

After doing the research and seeing the numbers, I modified my inspection software to include mention of safety glass. On those occasions where I can efficiently identify the glazing, I comment on that. And, if I can't, I now explain the significance to the client with a recommendation to upgrade the glazing in the danger zones - next to walking surfaces, sliding doors, bathrooms, etc.

I think the Standards should be changed to reflect the actual risks that homeowners (and their children) face. It would not be hard to include a statement that says, "Glazing manufactured prior to the 1970's was usually not tempered and many time glass manufactured prior to 2010 was unmarked, preventing positive identification of safety glazing. Untempered glass can shatter into shards under impact. Recommend consulting a glazing contractor to upgrade windows and doors that may be at risk in order to improve homeowner safety."

Now I just have to convince the other inspectors.

What are those stripes on my wall?

I had a chance recently to perform a "mold' inspection. The occupant of the home complained of mold growth and was particularly concerned about the stripes that were growing on his walls.

I performed a visual exam the walls but the issue was obvious as soon as I entered. .The striping effect I saw is typical marking that occurs in older homes that limited wall insulation and (generally) a four-inch wall cavity.

The striping is not a biological growth but the result of house energy dynamics and occupant behavior. In the wintertime, the studs are substantially cooler than the cavity spaces. The movement of warm air is to the cooler stud, consistent with the Second Law of Thermodynamics. When the air reaches the painted drywall surface, it deposits oils, dust, and smoke on the surface. The reason that the nails show more on the wall surface is that they are metal and better transmitters of energy, and thus colder.

 A lot older houses that had smokers exhibit these types of stripes. Other causes are the cooking greases and smoke from the kitchen, oil-based air fresheners, wood fireplaces, and candles.

Candles are a biggie.

So my advice is not to panic. Clean the walls, and then assess which of the likely causes put the particulate matter into the air in the first place. Once you determine that, you have a means of control.