Vinyl Siding: A flammable material

A few weeks ago a friend called me to say he had some pictures I should take a look at. He told me that a relative of his living in Vaudreuil, (west of Montreal) was hosting a few friends on his back deck one evening when a cigarette was apparently stubbed out in a planter around 9pm, (there were no ashtrays as the hosts did not smoke).

The planter contained peat moss which smoldered slowly until midnight, when it burst into flame and ignited the vinyl siding, breaking a window and setting off the burglar alarm. Within just 10 minutes, the house was totally engulfed in flame, the occupants escaping with nothing much more than their underwear.

Looking at these photos, the interesting – and I think more frightening – aspect, is the effect on the house next door. This house is about 20 feet away. Note the condition of its vinyl siding.

Other fires involving homes with vinyl siding have been more serious. A Virginia fire in 2004 was described by the Washington Post this way: “A tiny flame from a candle touched papers that melted vinyl siding and set off a fire that raced unnoticed up three floors. The blaze torched 18 condominiums, left three people dead and forced a man on fire to leap from a third-floor balcony.”

The safety of vinyl siding now being food for thought, I decided to do some research on the web to see what I could come up with. (Surprisingly little!)

Although its application as house siding is fairly recent, the synthetic material known as PVC (or Polyvinyl chloride) has been around since the 19th century. It is used to make everything from credit cards and electrical cable, to clothing and of course, building materials.

Here are some other interesting points I found in that Washington Post article:
“Building suburban-style houses at an urban density could cause conflagrations that could devastate whole neighborhoods, fire officials warn. A 1988 Canadian study of two similar structures 5.9 feet apart showed that it took 4 minutes and 50 seconds for the second house to ignite. Thirty seconds later, the second house was fully engulfed.

“Reliance on newer materials and technology is resulting in buildings that some say are less sturdy than houses of the past. Using vinyl siding instead of stucco or masonry, smaller and drier timber, and home furnishings made of plastics and chemicals that create a toxic smoke when burned make newer houses more dangerous, some experts say.

“It is not unusual, fire fighters say, for people trapped in building fires to die from inhaling chemically toxic fumes before the flames actually reach them.”

When I do a building inspection and I see exposed foam insulation in the garage or basement, I recommend it be removed or covered with drywall because of the fire risks and the toxic fumes produced. According to a 1999 Greenpeace article, “…acid smoke and the carcinogen dioxin are released when vinyl siding burns or melts in a house fire. It is not unusual, fire fighters say, for people trapped in building fires to die of chemically toxic fumes before the flames actually reach them.” I would not normally think of warning my client that the vinyl siding on the outside of the house he is thinking of buying may kill him.

Back to the original question. I am not sure of the right answer, but if you are planning to install vinyl siding, take care with BBQ’s and peat filled flower pots, and consider how close you are to your neighbour …who may not be so careful.