Death by Deck

Member
Provider Advisory
Council

NC License 1069

Death by Deck

Issue: 91 February 7, 2004

Death by Deck

When you are showing that next house, be careful when you step out onto the wood deck. This spring in Cobb County Georgia a couple, along with their daughter and son-in-law, were house hunting on a Saturday afternoon. You would think that house hunting on a bright, shiny spring day would be a low-risk activity, right? Well not today. As they walked out onto the spanking-new 25-foot-high wood deck, it fell right out from under them. Believe it or not, I often see wood decks I am uncomfortable walking on or under. I still have memories of one deck I wrote in the report not to allow anyone to walk on until it was repaired.

I know this is a little stretch, but well worth it to make the point. How would you feel if the death certificate of a person you sold a home stated “Death by Deck”? Read on and learn why you and your clients should be concerned about the wood decks on the homes you list and sale.

Wood decks are wonderful. I have a massive one on the rear of my home. Wood deck collapses in recent years should be sounding the alarm that improperly constructed, inadequately maintained wood decks, combined with lack of intelligence, can become horrible scenes of pain, injury, death and litigation. Could the wood deck on the home you just sold be the next in the headlines? Check out these, among which on one deck 13 died and another a judge awarded the injured a judgment of $12 million dollars:

Martha’s Vineyard, January 31, 2004: “… Deck Collapse Tied to Rotting Beams” … injured people at a party. 20 people were on the deck at the time of the accident…

Portsmouth, New Hampshire, August 11, 2003: “Eleven injured in deck collapse” … collapsed during a birthday party for a woman who turned 80 and was among 11 people treated at a hospital. Nearly 40 people were on the deck when it collapsed…

Kansas University, September 23, 2003: “athletes injured in deck collapse” …between 20 and 50 people were gathered on the … deck when it collapsed.

Gauley Bridge, West Virginia, July 4, 2003: … about a dozen were injured after the crowded deck they were standing on collapsed.

Chicago, June 29, 2003: “Porch collapse kills 12 at Chicago party” Two wooden porches laden with college students collapsed during a party killing 12 people and injuring 57 others. (Note that on July 2nd the 13^th person died)

Des Moines, June 23, 2003: “Eight injured when deck collapses” … after a wooden deck holding birthday party guest collapsed onto several people.

Birmingham Alabama, June 3, 2003: “Deck Collapse Injures Children” Twenty-three children transferred to area hospitals.

Marshall University, Huntington, West Virginia, May 17, 2003: 17 people were injured after a deck collapsed.

New Jersey, July 2002: “Thirty-One hospitalized following deck collapse”

Sugar Mountain, North Carolina, June 8, 2002: “Twenty Five Injured when Deck Collapses”

Lyons, Oregon, September 27, 1999: … a wood deck packed with wedding guests collapsed, killing one woman, leaving another in critical condition, and injuring 23 other people.

Cincinnati, September 7, 1999: “Deck collapse reason sought” …thirteen people were injured and taken to three hospitals.

Gaithersburg, Maryland, “Eight hurt in Tuesday night deck collapse” Inspectors … checking decks in the neighborhood … found that at least 70 decks did not … meet inspection standards. Inspectors said the cause of the collapse could be traced to the use of nails instead of bolts to secure the deck to the home. … the deck was built without a permit and never inspected by the city officials.

San Francisco, February 17, 1996: “Deck of Death” 32 year old Mary Ellen Slane … was killed and 14 others were injured when the deck at 2003 Franklin Street busted, sending the doomed party guest crashing … to the ground. In addition to Slane’s death, the horror caused a crushed face, fractured pelvis, leg fractures, bruises, abrasions, and other massive head injuries to the guests. Injured guests and Slane’s widower sued the owner and were awarded $12 million by a judge, one of the highest awards ever in San Francisco for landlord negligence.

Atlanta, April 9, 1995: “It looked like a battlefield” … a prominent Atlanta citizen’s … backyard … deck collapsed during a party, with 63 people on top… Ambulances jammed the street as rescue workers helped people with broken pelvises, broken backs and third degree burns … from the torrent of overturned grills and chafing dishes.

Why do wood decks fall and why don’t we witness more failures?

Robert Falk, a structural engineer with the U. S. Forest Products Laboratory in Madison, Wisconsin, five years ago, used a data base to search five years of newspaper articles from around the country and found that nearly every collapsed wood deck had been attached with nails, rather than bolts, and that the investigators had pinpointed the nails as the cause of collapse.

I am personally convinced that the only reason we don’t witness more wood decks falling are the simple fact that most decks aren’t occupied by large numbers of moving people. Have one party on your nailed wood deck with lots of wild dancing people and there is a very good chance your deck will fall. Fortunately, most of our decks just sit there soaking up the sun. Unfortunately, it only takes that one party to bring on disaster. You rarely see or hear of deck tragedies where there are not multiple deaths or injuries. It is not because they don’t happen, but because they are not considered sufficiently newsworthy.

A safe wood decks depends on three things:

The deck must be designed and built correctly using proper materials and hardware.
The deck must be properly maintained.
The deck must not be overloaded or improperly used.

The construction of wood decks are addressed in Appendix M of the North Carolina Residential Code and are subject to permitting and inspections by local code enforcement authorities. Experienced builders who know what materials to use and how to build a safe deck should construct wood decks.

Pertinent issues that should be considered when you are purchasing a home with a wood deck:

Decks and their associated stairs and landings should not move!!! Movement, other than slight deflection, is good evidence of poor construction practices.
Treated wood, or the equivalent, should be used for construction. Today we observe composite materials and plastics, which may have different requirements not addressed here.
All hardware used for construction should consist of nails, screws, bolts and hangers of non-corrosive materials such as stainless or galvanized steel.
All bolts should be hot dipped galvanized minimum 5/8” diameter with washers at bolt heads and nuts. Wherever possible carriage bolts w/nuts (see illustration at right) rather than lag bolts should be used.
At the connection to the house present code calls for a minimum of one bolt ever 2’-4” on spans up to 8 feet and 1’-4” on spans greater than 8 feet.
The connection at the house should be flashed to prevent water infiltration into the floor structure of the home leading to moisture damage, rot and termites.
Support post must be a minimum of 4”x 4” increased to 6”x 6” if over 8 feet high and must be buried in the ground or otherwise secured in place such as on a concrete footing.
All support post must be braced with bolted 4x4's or 2x6's extending down one-third the post height on a 45 or 60 degree angle. Alternatively the post may be buried in the ground adequately to provide for lateral bracing. The depth required depends on the height of the deck but will be multiple feet.
All beams or girders must be doubled where the floor joist attach.
All floor joists must rest on top of the supporting beams/girders or on ledger strips or joist hangers.
Handrails and guardrails must be provided and firmly attached on all decks or portions thereof, which are more than 30” above grade. These railings must be able to support 200 pounds of pressure exerted on them per foot of length. Handrails must be between 30" and 38” above the stair nosing and guardrails must be not less than 36” high. Railings must not permit passage of an object 6” in diameter. Limit horizontal members to prevent creating a ladder for children to climb over.
Stairs must be adequately secured at the top and bottom and be appropriately braced to prevent movement.
There should be no nails which are backed out and nails which are should be overdriven back in place.
There should be no excessive splintering or cracking of wood, broken or loose components.
There should be no rot, decay, soft spots or insect damage.
Ideally the wood should be sealed with a good coat of exterior grade wood sealer/water repellant.

Carriage Bolt

Lag Bolt

Operation of your deck:

Do you know how many people can safely be on your deck? Properly designed and constructed wood decks have a 40-pound per square foot live load capacity. This would be no more than one 200-pound person for each 5 square feet (an approximately 2’ x 2’ area) of deck. Stated such it doesn’t sound like much but that is 28 – 200 pound people or 5600 lbs on a 12’ x 12’ deck, which is greater than the weight of an average car. You must be aware that these people must be evenly distributed on the total deck. Crowed them together and you overload the deck.
Dancing by large numbers of people, heavy drinking or roughhousing (people do fall over railings) should not be allowed. Armies since Julius Caesar have not marched over bridges for fear of the cadence of their march destroying them. Movement on a beat or to a rhythm could be the last straw to destroy an otherwise apparently “safe” deck.

We can put a stop to injury and “Death by Deck”. Try not to be so upset when your clients home inspector address’s deck issues. A few simple inexpensive bolts and/or braces may save a life or prevent serious injury.

Thoughts for the week...

Inspiration exists, but it has to find you working. -Pablo Picasso

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