May is National Deck Safety Month

By
Home Inspector with About The House

Deck safety… May is National Deck Safety Month!

Don't let this happen to you! This was next door to a house I inspected on Friday!

deck

Deck failure is a fairly common occurrence in the United States. From Jan 2000 through Dec 2006, there have been 179 reports of deck & railing failures. In these events, 1,938 people were exposed to injury (33 people died). Many more deck failures probably occurred; it is also believed if no injuries were involved, the failure was not reported.

•    Fiction: Deck failures are a direct result of overloading.

•    Fact: Deck failure is caused by improper connections, wood rot or even corrosion of the connectors.

Most experts agree the normal life expectancy of a deck is about 15 years. They also agree most deck connections and/or deck components are subject to failure long before the end of the service life of the deck.

Unfortunately, it’s not only the deck or the deck connection, it could also be the rim board that’s already installed on the house. Several deck failures were a result of the rim board pulling off the house (this will result in a code change [2009 for NJ]).

Building a deck is the same as building a house. All the structural elements of the deck need to have what’s called a continuous load path. Every element of the continuous load path needs to be secured to the element that is supporting it. The columns need to be secure to the footing; the beam needs to be secured to the column, the joists need to be secured to the beam and so on and so on. There are 3 types of forces that put pressure on a deck; Gravity, Lateral and Uplift. Positive connections will withstand all 3 forces.
Positive connections ARE NOT achieved by nails; nails are subject to withdrawal. This does not only mean the ledger to the rim joist, it also means the joists to the beam and the beam to the columns. Hey, don’t forget about the stair stringers to the deck!

www.deck-lok.com (Deck-Lock) has developed a new bracket system that will hold the house rim board to the interior joists and hold the deck rim board to the house rim board. This new bracket will help prevent ANY type of pull-out of the deck from the house connection.
This new bracket is also a positive connection of the rail posts to the deck; how many deck rails have you seen that were not tight; no matter how it was nailed or how many fillers were added, the rail post is extremely difficult to properly secure.

Now, let’s look at other problems we find while inspecting decks:

1)    Footing too small. - The IRC REQUIRES a footing be no less that 12 inches wide.
2)    Posts not connected to the footings. – The post must be ANCHORED to the footing.
3)    Wood posts are notched. - Notches in the post will allow spliting, resulting in a shearing of the post.
4)    Beams not secured to the posts.- Nails do not serve this purpose.
5)    Joists not secure to the beam. - Again, nails do not serve this purpose.
6)    Handrail loose, spacing exceeds 4 inches or worse yet, handrail not graspable. Remember, any type of 2X used as a handrail is not acceptable.

So, for the safety of all occupants, have your deck properly inspected; safety first!

Here are other links to deck connectors:

www.strongtie.com/safedeck/index.html?source  (Strongtie safedeck)


www.strongtie.com/ftp/bulletins/T-DECKB_English.pdf  (Strongtie Bulletins)

Comments (2)

Reuben Saltzman
Structure Tech Home Inspections - Minneapolis, MN
Delivering the Unbiased Truth.

Daren - that's a great list of common deck defects.

Apr 25, 2010 02:00 PM
Hank Spinnler
Harmony Home Inspection Services of GA - Hoschton, GA
Atlanta Home Inspector

Hi Darren.  I wonder what happened there.  The grill looks like it survived.  Every day I'm working is "deck safety month" for me.  

May 09, 2010 01:13 PM