Deck Safety 101: How to Inspect your Outdoor Space

Your Deck Inspection Checklist

Is your deck showing some signs of wearing? Most deck structures are much more susceptible to corrosion and wear than the house they are attached to. They are usually directly exposed to the elements and are often not designed by professionals but added to the home as a DIY addition or an off-the-shelf product.

The truth is that your deck may look fine on the surface, but structurally, it is overdue for repairs and could quickly become a safety hazard. This article provides a basic deck inspection checklist of possible structural issues with your deck. It also provides you with the correct steps to affect lasting deck repairs and ensure proper deck maintenance.

Before we jump in, let’s highlight the importance of professional engineering advice when doing structural inspections and repairs. Engineers have a trained eye and understand the limitations of structural support components. Even when the code doesn’t require it, hiring an engineer will increase the longevity of your deck and help it stay maintained properly.

What is the Risk of Not Doing a Thorough Inspection of My Deck?

Additions and deck extensions without approvals or code compliance are common. As a result, issues such as aging infrastructure and poor DIY construction contribute to the over 2900 injuries resulting from deck or deck-related structural damage each year in the USA. (CPSC.gov)

Whether or not your deck requires a building permit depends on your local requirements. It may also depend on its size or height above ground level. Nonetheless, you want to ensure its stability and the safety of those who use it. In that case, it is critical to consult professional structural engineers to undertake a proper inspection and certify that your deck is structurally sound.

Construction that is not according to the code or done without proper knowledge and experience can lead to accidents and loss of investment.

One of the most significant risks in non-compliant decks is the size of openings in handrails and guardrails. The construction code was recently modified to a smaller opening of 4 inches to mitigate the number of infants and small children falling through or getting stuck in guard rails.

If you spend more and more time on your outdoor living space, you may want an engineer to carry out a professional deck inspection for deck safety.

Need advice on how to go about professional home inspections? Check out our blog below:
https://levelengineering.com/b/building-inspections/the-role-of-private-building-inspectors-in-residential-construction-projects/

What Problems Am I Looking Out For?

Ledger Boards:

One of the most common problems with decks is improperly installed ledger boards. Ledger boards are commonly expected to carry 400 lbs per linear foot. Still, many decks have been wrongly connected to the house itself, resulting in structural issues, damage to the home, and deck safety concerns.

For example, if a home has siding, the siding must be removed and flashed during construction. Flashing details are the process of adding a strip of water-resistant material against the house to prevent water from reaching the deck’s frame and structural support elements.

Ledger Board Attachment

In the picture above, the deck’s ledger board was attached to the house through the brick veneer, which is not intended to carry a load. The improper addition has caused wood rot and caused the deck to pull away from the house.

Deck Posts:

Deck posts sometimes need to be more adequately attached to their concrete footings. The load transfer between support posts and base support is an essential and common source of deck fails inspection cases. We often see deck post footings that are not correctly sized. In the footing world, one size does not fit all, primarily due to the variability of soil strengths. The footing size is determined based on the total post load and the soil type.

Wooden framing elements, such as posts and bracing, attached to the foundation must be at least six inches above the soil, per code, because they can rot. The bracing elements in the photo below had completely rotted and pulled apart at their connections because the foundation connection is below soil grade.

Bracing Element Below a Deck

This real-world example shows the severe impact of improperly installed support posts. Moisture exposure and lack of elevation caused the wood to deteriorate and compromise the deck’s structural integrity.

Handrails and Guardrails:

Handrail and guardrail connections are another common area of failure. They are typically required to resist more than two thousand pounds of force for each support post. The Residential Code specifically outlines these requirements with definitive height and width requirements. Our engineers have seen numerous handrails that are improperly attached to the deck, which can be the sole cause of injury.

Guardrail Connection to Surface of Deck

We frequently see guardrail connections like the image above. This deck is approximately 30” off the ground with shaky railings. This is mainly due to the railing post being attached directly to the deck surface, which is unsafe and unattractive. Attaching them to the deck’s framing is a safer way to construct guardrails.

Stair Stringers:

A stair stringer, or stringer board, is a set of boards that support stairs. Each stairway is typically required to help thousands of pounds—equivalent to driving your vehicle up the stairs. The stair stringer must be accurately measured in many different ways; the depth, the riser height, and the maximum variance are all integral parts of the stairs’ safety. Very frequently, they are not to code and cannot support the required loads.

Improperly Spanned Staircase

Below is an example of an over-spanned deck that was not appropriately supported. The stairs lacked proper bracing and failed to meet span requirements. These will need to be demolished and relocated to a different section of the deck.

Comprehensive Deck Inspection Checklist

Structural Support and Foundation

Start your annual deck inspection with your deck structure’s foundation and support posts. Check for the following:

• Concrete Footings: Ensure that concrete footings are in good shape and provide stable base support for the deck. Look for signs of cracking or shifting.
• Support Posts: Inspect the base of the support posts for any signs of wood rot or moisture damage. Posts should be at least six inches above the soil to prevent direct contact with moisture.
• Joist Hangers and Span Braces: Verify that joist hangers and span braces are securely attached and show no signs of rust or structural damage. Loose or missing hangers can compromise the deck’s structural integrity.

For more checklists on structural inspections, click here

Deck Surface and Flooring

The deck surface of your decking is exposed to the elements, making it susceptible to wear and tear. Pay attention to the following areas:

• Decking Boards: Inspect decking boards and deck boards for any sagging boards, cracking, or splitting. Replace any damaged boards to maintain a safe walking surface.
• Deck Flooring: Check that your deck flooring is level, secure, and free of splinters or exposed fasteners.
• Composite Decking: If your deck is made of composite decking, check for signs of warping or discoloration. Composite decking is durable but still needs regular inspections.
• Nails Popping and Screws: Look for nails popping out or screws that have become loose. These can create tripping hazards and signal that your deck needs repairs.

Railings and Stairs

Railings and stairs are critical for deck safety.

• Handrails and Guardrails: Handrails should withstand a force of at least 200 pounds. Check that all railings are firmly attached and show no signs of loose connections.
• Stair Stringers: Inspect the stair stringers for proper alignment and insect damage. They should be structurally sound.
• Fasteners and Lag Screws: Ensure all fasteners and lag screws are tight and free from rust. Replace any corroded parts to maintain structural integrity.

Deck Attachments and Connectors

How your deck attaches to your house is vital for deck safety:

• Ledger Boards: Ensure ledger boards are correctly installed and inspected. Check for flashing details that prevent water from causing wood rot.
• Metal Plates and Sheet Metal: Look for any metal plate or sheet metal used in framing. Make sure these components are intact and not rusted.

Common Issues Identified During Deck Inspections

Even decks constructed to code have a limited lifespan. Although your deck can outlive you, it requires deck maintenance and deck inspections for the following issues:

• Wood Rot and Moisture Damage can significantly weaken your deck’s structural supports. Check the wood ends, corners, and beneath decking boards for signs of decay.
• Insect Infestation: Look for carpenter bees, carpenter ants, and signs of an insect infestation. Boring holes and frass can indicate a problem.
• Water Stains and White Stains: Water stains on the deck surface or framing can indicate water damage. White stains may point to mineral buildup from long-term moisture exposure.

The Importance of Professional Deck Inspection

While a DIY deck inspection can catch many issues, a professional inspection ensures a thorough inspection of your deck’s condition. A professional inspection includes everything in this deck inspection checklist and more.

Benefits of Hiring a Professional Inspector

• Expertise: A professional inspector can inspect everything from fasteners to base plate integrity.
• Safety: Ensuring your deck meets local requirements and safety codes can help avoid lawsuits, injuries, or worse.
• Long-Term Savings: Preventative deck maintenance and regular inspections help avoid costly structural repairs later.

Steps to Take If Your Deck Fails Inspection

Discovering that your deck fails inspection can be alarming, but it’s the first step to restoring a safe and enjoyable outdoor living space. Here’s what to do:

1. Review the Inspection Report Start by understanding the identified issues—from structural problems to insect damage or corrosion of a metal plate.
2. Prioritize Safety Issues Fix hazards first: loose railings, sagging boards, failing deck boards, or rotted framing should be addressed immediately.
3. Consult a Professional Engineer. They will help design a solution, assess your deck’s structural integrity, and ensure repairs follow the code.
4. Develop a Repair Plan Include:

• Replacing deck boards and decking.
• Reinforcing joist hangers, support posts, and deck attachments.
• Upgrading to pressure-treated wood or composite decking.

1. Ensure Proper Installation and Materials Use code-compliant, weather-resistant products and the correct methods to restore the deck structure.
2. Schedule a Follow-Up Inspection Once repairs are done, confirm your deck is safe by inspecting it again.
3. Implement Regular Maintenance Adopt a schedule of annual deck inspection, sealing, cleaning, and repair to ensure a long-lasting deck.
4. Educate Yourself on Deck Safety Knowing what to look for helps ensure you catch early signs of structural issues, rot, or insect infestation.

Whether you need an inspection, repairs, or a complete deck replacement, Level Engineering is here to help. Call (866) 523-3413 to speak with our team and schedule your professional deck inspection today.