Scenes from a deck collapse in South St. Louis City, Spring 2010.

With the recent collapse of a 2^nd story deck in South St. Louis City (injuring 7), that brings us to a total of two major deck collapses in St. Louis in less than a year. And the 2010 outdoor season has only just begun.

So, it is the season to get serious about deck safety. Did you know nearly 85% of homes in the United States have a deck, and the North American Deck and Railing Association estimates that 20 million of these decks are in need of repair or rebuilding?

In the past 10 years, there have been more than 800 reported injuries and at least 30 reported deaths as a result of deck collapses, and this number increases at an average rate of 21% per year. In many cases, the failing decks were built incorrectly, not properly maintained or were beyond their lifespan of approximately 10-15 years.

With every deck collapse that makes the news, Mosby Home Consultants are called out to evaluate deck conditions because they are experienced in evaluating both the deck and the contributing factors that may be overlooked by less experienced carpenters.

Mosby Home Consultants inspect several problem decks a month, and these are the 10 most common mistakes they see:

10. Unsealed wood
Unsealed wood decks can age and deteriorate faster than sealed decks. Proper sealing prolongs the appearance and life of a deck well beyond unsealed decks. Avoid the “worn out” look by sealing it.

9. Stairs with open risers or missing railings
Open space between steps invites accidents. Avoid injuries and create a tailored look by covering the risers. Hand railings are fundamental to the safety of a stairwell.

8. Improper railing height and baluster spacing
Building codes have very specific measurements for railings and balusters to avoid accidents and injuries.

7. Undersized structural members
An undersized structural member increases the risk of deck collapse and can create sagging and improper weight distribution. Avoid deck warping and collapsing by properly sizing all members and components of your deck.

6. Missing or improper joist hangers
Nails alone are not enough to counteract the shear forces on a structural member. Joist hangers are an essential element in creating reinforced connections and supported decking. Ensure the safety of your deck by using properly sized, engineered, and correctly installed joist hangers.

5. Improper Deck Materials
Weather resistant materials are necessary on exterior structures to prevent rot or deterioration. There are specific fasteners for exterior conditions and it is critical that the proper fasteners are used. Select materials that are expressly made to withstand all weather conditions.

4. Undersized footings
Footings create a solid base for the posts of your deck. Undersized footings can lead to sagging, warping or collapse.

3. Improper attachment to structure of house (incorrect fasteners)
How your deck attaches to your home determines its safety and durability. This is an area that you may want to overbuild beyond the minimum standards or requirements. Again material, size, and quality are critical.

2. Improper or missing flashing
Every deck must address water management. Water can soak into your home at the point where the deck connects to the house. Properly installed flashing will prevent erosion to the structural integrity of your deck and home.

1. Not obtaining a permit to build a deck
Obtaining a permit is the most overlooked step in deck building. Safety is the main focus of following the permitting process of your town.

The majority of deck building mistakes can be avoided by applying for a building permit through your City Hall. The permit process requires drawings and specifications of the proposed deck. Building Inspectors will verify that the deck plans meet the local building and safety codes. This crucial step will save you from making costly mistakes before the first hammer swings. The permit process requires on-site inspections during construction phases to insure the deck is being built according to code.

It is crucial for the safety of your family and your guests that a deck is built properly. Mosby Building Arts’ staff of planners will handle the design, drawings and permit applications. Furthermore our carpenters will build a deck of beauty, enduring quality and utmost safety for your family and friends outdoor enjoyment for years to come.

If your deck is showing even one of the 10 signs of an unsafe deck, call Mosby for deck inspection and repair at 314.909.1800 or contact us here.

It’s the time of year when parties and celebrations are happening all over the United States because July 4^th is upon us. Can your deck stand up to the weight, vibrations and movements of your guests? Has it deteriorated over the years from being exposed to the weather? Was it built with the correct engineering and in compliance with the code?

We strongly recommend you look into the condition of your deck. Not only the integrity of the wood, but its attachment to your house, the flashing, the size of the structural parts and the anchors. Many decks were built without checking into the proper engineering for the load and materials used. Building codes have been updated in some municipalities to consider the risks, but who built your deck and did they go through the correct process to obtain a building permit?

Did you know nearly 85% of homes in the United States have a deck, and it is estimated by the North American Deck and Railing Association (NADRA) that 20 million of these decks are in need of repair or rebuilding?

In the past 10 years, there have been more than 800 reported injuries and 20 deaths as a result of deck collapses, and this number increases at an average rate of 21% per year. In many cases, the failing decks were built incorrectly, not properly maintained or were beyond their lifespan of approximately 10-15 years.

St. Louis is one of the top ten cities in the nation that have reported one or more deck collapses in the last 10 years.  Our region’s latest deck collapse happened on June 11, 2009 in Wildwood, MO, and recently Scott Mosby was asked to contribute his views on proper deck maintenance to a West County Suburban Journal article on deck safety. Read the article here.

Previously, we identified the Top 10 Mistakes of Deck Building, and to that we add the 7 warning signs that a deck is unsafe:

1. Loose connections – are your railings, deck boards, or structure loose at the connections?

2. Missing connections – are all the fasteners still working and in place? Do you have the proper joist hangers? Are they the right size?

3. Corrosion – do you see any metal parts that show rust?

4. Rot – are any wood or metal parts showing decay?

5. Cracks – can you detect any horizontal or vertical pieces of wood breaking apart?

6. Fastener size & number – has your deck been attached to your house correctly?

7. Posts – are your posts right on the ground or do they have the proper footings, piers, and anchors?

According to a Morse Technologies, Inc. report, 90% of deck failures are due to how the deck is connected to the house. We recommend that you review your deck today to see if it is attached similar to the diagram shown above.

Caution for the upcoming weekend is the proactive decision because virtually all reported deck collapses occur while the deck is occupied, and most collapses take place between June and August. As we are in the heart of summer entertaining season, we strongly urge you to have your deck inspected now so you can avoid serious injury to people and damage to your home.

Mosby Building Arts has recently been called out to several homes for our paid consultation visit to evaluate deck conditions after deck owners heard of the collapse in the St. Louis area. We not only evaluate your deck, but also find other contributing factors that may be overlooked by a less experienced carpenter.

Shown above is a photo of a deck we inspected last week whose vertical supports had uniformly shifted off-center of their concrete footings. With further investigation through our consultation visit, we found the flashing was missing and there was water damage on the inside of the house. The bolts used to hold the deck on the house were insufficient and the safety of this deck has been compromised.

We also visited another deck that the owner thought he was taking care of his concerns by replacing some rotted deck boards. The carpenter replaced the boards but neglected to see the water damage, the insufficient connection to the house and the lack of stability in the structure for proper support. The entire deck was built incorrectly and needs to be replaced.

Know that we think differently and want you to have peace of mind during your celebrations. Let our deep bench of professionals discuss your concerns. Call for a deck evaluation at 314.909.1800 or contact us here.