Common Deck Issues Found During Home Inspections

A well-built deck adds tremendous value to a home, providing an outdoor space for relaxation and entertainment. However, decks are exposed to the elements year-round, which can lead to wear and structural issues over time. A thorough home inspection will typically highlight any concerns with a deck’s structure, which can affect both its longevity and safety. In this post, we’ll explore the most common deck issues found during home inspections and why addressing them is critical.

Improper Ledger Board Attachment: Nails Instead of Lag Bolts

One of the most critical aspects of a deck’s structure is the ledger board, which is the part of the deck attached to the house. The ledger board supports a significant amount of the deck’s weight, and improper installation can result in catastrophic failure. A common issue found during inspections is the use of nails instead of lag bolts to secure the ledger board to the house.

Nails simply do not have the strength or durability needed to hold the ledger board securely, especially under heavy loads or over time as the wood expands and contracts. Lag bolts, on the other hand, provide a much stronger connection, anchoring the deck to the house framing. If a home inspector finds nails instead of lag bolts, it’s a red flag that the deck may not be securely fastened.

Missing Flashing

If a deck’s ledger board interrupts the siding, flashing is required. If flashing is missing, water can enter behind the ledger board and cause water damage to the home’s wall structure. This can allow mold growth and the need for costly repairs.

Missing Joist Hangers

Joist hangers are metal brackets that support the deck’s joists, which are the horizontal beams that form the foundation of the deck surface. These hangers help distribute the deck’s load and prevent the joists from shifting or failing over time. During inspections, missing or improperly installed joist hangers are often flagged as a major safety concern.

Without joist hangers, the deck’s structure is compromised, increasing the risk of joists detaching from the ledger board or beams, leading to sagging or even collapse. Missing joist hangers are often the result of poor workmanship, and home inspectors will typically recommend their immediate installation to restore the deck’s structural integrity.

Wrong Fasteners and Connectors

Deck fasteners (nails, screws, and bolts) and connectors (joist hangers, corner brackets, etc.) must be appropriate for outdoor use and rated for the weight they support. A common issue during inspections is the use of improper fasteners, such as interior-grade nails or screws that aren’t designed to withstand moisture and the elements.

Using the wrong fasteners is one of the most common deck issues found during home inspections. It can lead to corrosion, weakening the deck’s connections over time. This can result in loose boards, failing joists, or even dangerous structural weaknesses. Inspectors will check for rusted or corroded fasteners and may recommend replacing them with corrosion-resistant options like galvanized or stainless steel hardware to ensure the deck’s longevity.

Over-spanned Joists

Deck joists must be spaced and sized correctly to support the weight of the deck and the load it will carry, including people, furniture, and other objects. Over-spanning occurs when the distance between the supports for the joists exceeds what is safe or recommended by building codes.

Over-spanned joists can lead to excessive flexing, sagging, and eventual failure. During home inspections, over-spanned joists are a major concern because they compromise the structural integrity of the entire deck. Correcting this issue may involve adding additional support posts or reducing the span between joists.

Improper Post Installation

The posts supporting a deck must be installed correctly to provide adequate support and stability. Two common post-installation issues often found during home inspections are:

• Posts not installed under framing and instead nailed to the side of beams or end rim joists. With this installation, the weight is being transferred to the fasteners attaching the posts to the deck, rather than directly transferring the weight to the post itself.
• Posts not centered on concrete footings: Deck posts must be securely anchored to properly sized concrete footings. If the posts are not centered on the footings, the load is unevenly distributed, which can cause the footings to crack or shift over time, leading to instability in the deck.
• Posts with no footings or improper footings. Posts must be installed on solid footings to prevent movement. Often posts have no footings or improper materials used as a footing such as a concrete block, a brick, or even just a rock. Some footing blocks are designed for free-standing, low-to-the-ground decks. Often these footing blocks are found installed on decks that they are not designed for.

These installation issues can significantly weaken a deck’s structural support. Home inspectors will often recommend repositioning or replacing posts to ensure they are installed correctly and provide the necessary support.

Rot and Water Damage

Rot and water damage are common deck issues found during home inspections with older decks, especially if they have not been properly maintained. Wood decks are particularly vulnerable to moisture, which can lead to rot, mold, and mildew if the wood is not adequately protected by sealant or paint.

Inspectors will check for signs of rot in the deck boards, joists, and posts and around fasteners and connectors where moisture can accumulate. If significant rot is found, portions of the deck may need to be replaced to ensure it is structurally sound.

Loose or Warped Deck Boards

Over time, deck boards can become loose or warped due to natural expansion and contraction, improper installation, or exposure to the elements. Loose boards are not only a tripping hazard but also an indication that the deck is beginning to deteriorate.

Inspectors will look for boards that are popping up or warping and may recommend re-securing or replacing them. Regular maintenance, such as tightening screws and replacing damaged boards, can help prolong the life of the deck and keep it safe for use.

Conclusions on Common Deck Issues Found During Home Inspections

A deck can be a superb addition to a home, providing an outdoor space for gatherings and relaxation. However, it’s essential that a deck is built and maintained to meet safety standards. Common deck issues found during home inspections such as improper ledger attachment, missing joist hangers, wrong fasteners, over-spanned joists, and improper post installation can all compromise the safety and structural integrity of the deck.

Addressing these issues promptly not only ensures the deck remains safe to use but also extends its lifespan and maintains the value of the home. If you’re considering purchasing a home with a deck, or if your current deck is showing signs of wear, a professional inspection and any necessary repairs can help protect your investment and provide peace of mind.