Most experts agree that the average life expectancy of a wood deck is 10 to 15 years. There are millions of decks in
the U.S. that are beyond their useful life and may be unsafe. Since 2003, deck collapses have caused thousands
of reported injuries* and several deaths.
As you evaluate the safety and construction of your new or existing deck, knowing these simple steps will help to ensure your
deck is structurally sound and properly maintained. We’ve included a list of warning signs, so you’ll know what to keep an eye
out for on your deck.
1. Check Out Your Deck
The first step in making your deck safe is knowing that it
may not be. Decks are potentially the most dangerous part
of the house, according to some experts. Factors, such as
improper construction, exposure to the elements and lack of
maintenance can make your deck unsafe. It’s important to
look for warning signs. If you are unsure about
the safety of your deck, consult with a professional such as a
structural engineer or contractor.
2. Carry the Weight
For most homeowners, the deck is a popular gathering
place for friends and family. Like a house, a deck must be
designed to support the weight of people and objects placed
on it as well as the forces of Mother Nature like wind, snow
and earthquakes. Knowing how weight and other forces can
affect the safety of your deck is important. There are
three types of forces that put pressure on
your deck, causing strain to the critical
connections that keep it together:
• Gravity – downward pressure typically
caused from people standing on the
deck or snow and ice.
• Lateral – a back and forth (horizontal)
motion caused by people walking on
the deck and/or leaning on a railing.
Wind and earthquakes also can
create lateral movement.
• Uplift – wind flows under the deck
creating a lifting effect. People
standing on the overhang of the
deck also creates upward pressure
on the connection that attaches
the deck to the adjacent support
structure, which is typically
3. Create a Path
A continuous load path, that is. A continuous load path is a
method of construction that uses metal connectors to create
a series of solid connections within the structure of the deck.
This path transfers the load or weight of the deck through
its frame and into the ground and adjacent support structure
(typically your home). If your deck is built with a continuous
load path, it will be better equipped to resist the forces that can weaken your deck.
4. Combat Corrosion
Decks and the metal hardware that keeps them connected
and safe are exposed to the elements every day. Over time,
metal connectors, screws and nails can corrode and weaken
the structure of your deck, especially if the right product is
not used. If you live in an area prone to moisture, such as
along the coast or near bodies of water, the risk of corrosion
is much higher. Chemicals in pressure-treated woods and
other corrosive elements also can damage your deck. Using
connectors, screws and nails that are made from stainless
steel is the best way to combat corrosion. When choosing
connectors, take into account where you live and how
weather and the environment may affect your deck. For
critical information about corrosion and connector selection,
5. Maintain a Safe Deck
Just like other parts of your home, regular maintenance and
inspection are required. To prolong the life of your deck,
you need to check for things like loose boards or protruding
nails. You also should keep your deck clean from debris
and depending on the type of deck boards used, keep them
sealed to protect against water and sun damage.
Is Your Deck Unsafe?
Look for the 5 Warning Signs
If you see any of these warning signs you should
consider repairing, retrofitting or rebuilding your deck.
1. Missing Connections: A deck should be
built using a series of wood members, nails,
screws and metal connectors to create a
continuous load path (see image on right).
Look at how your deck is built—if all you
see is nails, your deck may be unsafe.
2. Loose Connections: Depending on how the
deck was built, vital connections may have
degraded over time due to various factors.
Issues such as wobbly railings, loose stairs
and ledgers that appear to be pulling away
from the home are all causes for concern.
3. Corrosion of Connectors and Fasteners: Metal connectors, nails and screws can
corrode over time. Look for red rust and
other signs of corrosion that can weaken
the structure of your deck.
4. Rot: Wood can rot and degrade over time
with exposure to the elements. Wood
members within the deck frame that have
rotted may no longer be able to perform
the function for which they were installed,
making your deck unstable.
5. Cracks: As wood ages, it is common for
cracks to develop. Large cracks or excessive
cracking overall can weaken your deck.
Repairing or Retrofitting an Existing Deck
If you’ve determined your deck is unsafe, you’ll need
to either repair or retrofit it or in some cases, rebuild it
altogether. If rebuilding your deck is not feasible, there are
improvements you can do on your own to strengthen your
deck. However, some cases may require the professional
services of an engineer and contractor.Remember, when
hiring a professional, be sure they are licensed and have a
good reputation. Once the work is done, don’t forget about your
deck—it needs to be checked and inspected on a regular basis.
The Simpson Strong-Tie® Deck Framing Connection Guide can
help you through the process of making your deck safe, secure
and code compliant. You can download the guide or request a
copy at www.strongtie.com/safedeck.
*Based on data collected by the U.S. Consumer Product Safety Commission’s
National Electronic Injury Surveillance System.