Rotted Roof Decking

Rotted Roof Decking: What You Need to Know

Rotted roof decking is a serious issue that can lead to significant roof damage. When your roofing contractor removes old shingles, the underlying decking (or sheathing) may show signs of rot caused by water, poor ventilation, or aging. This can jeopardize the stability of your roof and lead to costly repairs. Here’s what you need to know about identifying and addressing rotted decking.

What Is Roof Decking and Why Does It Matter?

Roof decking (also known as roof sheathing) refers to the layer of material beneath your roofing shingles or other coverings. It typically consists of plywood or oriented strand board (OSB), and it serves as the base that supports the shingles.

Solid decking is critical for the roof’s overall strength and performance. Shingles cannot correctly adhere to the roof without it, leading to instability and roof leaks.

Why Does Roof Decking Rot?

Roof decking rots when moisture infiltrates the materials over time. Common causes of rotted decking include:

Water damage:
Leaks from damaged shingles, gutters, or flashing leads to moisture seeping into the decking.
Poor ventilation:
Inadequate airflow in the attic can trap moisture, which contributes to the rotting of the decking.
Age:
Over time, decking materials may weaken, especially if they have been exposed to moisture for an extended period.

Once rot sets in, it can spread, weakening the structural integrity of the entire roof system.

How to Spot Rotted Roof Decking

How can you tell if your roof decking has rotted? Watch out for these signs:

- Sagging roofline:
  A drooping or sagging roof indicates that the decking may be compromised.
- Water stains:

Stains on the ceiling or walls of your home are a sign of leaks that might be caused by rotted decking.

- Soft or spongy roof spots:

If you walk on your roof and feel soft spots, this can indicate rotted decking underneath.

- Visible mold or mildew:

Mold or mildew growth in the attic or roof’s underside can signal water damage and rot.

- Wet spots in the attic:

Moisture in the attic suggests that water has infiltrated your roof, potentially causing rot.

- Peeling wallpaper or paint:

Peeling wallpaper or paint can indicate moisture problems caused by rotted decking.

If you notice any of these, it’s time to check your decking.

When to Check Your Roof

Inspect your roof for decking rot twice—once before and once after harsh seasons like summer and winter. After heavy storms or extreme weather, inspect it right away to catch any moisture-related damage early. Early detection can save you from costly repairs later on.

Why Ignoring Rot Is Risky

Ignoring rotted decking can result in serious issues:

Roof collapse:
In extreme cases, rot can weaken the roof structure until it collapses.
Water damage:
Moisture can spread into your home, damaging insulation, walls, ceilings, and floors.
Mold and mildew:
Rotted decking can contribute to mold growth in the attic and other areas, creating health risks.
Increased repair costs:
The longer you wait, the more expensive the repairs will be as the damage worsens.

Repairing or Replacing Damaged Roof Decking

Once rotted decking is detected, it must be addressed promptly. A roofing contractor can assess the damage and determine whether repairs or a complete roof replacement are necessary.

Minor damage:
If only small sections of the decking are rotted, the affected pieces can be replaced without replacing the entire deck.
Extensive damage:
If the rot is widespread, the entire decking may need to be replaced to ensure its structural integrity.

The Repair Process:

Remove old shingles and other roofing materials
Inspect the decking
Replace damaged decking
Install new shingles

Dealing with Rotten Roof Decking in Your Roofing Project

When tackling a roofing project that involves rotten roof decking, it’s crucial to address the issue of rotted wood or wood rot quickly to prevent further damage. Rotten decking occurs when moisture infiltrates the roof, causing the roof decking (often plywood or OSB) to weaken, which can compromise the entire roofing system.

To repair or replace this damage, the affected roofing materials must be removed, including asphalt shingles and any compromised sections of the decking. Roofing nails secure the new decking and shingles, ensuring the roof remains stable and watertight.

Taking care of rotting decking early will protect your home from leaks and structural issues, ultimately extending the lifespan of your roof.

Act Early—Don't Wait for a New Roof

Early intervention can save you money and prevent further damage to your home. Whether you need a minor roof repair or a complete decking replacement, consult a professional roofing contractor to ensure the safety and longevity of your roof. Proactively addressing rotted decking will also help you avoid the costly need for a new roof.

Ask a ProfessionalAbout the Condition of Your Roof Decking

Rotted decking is a serious issue that can affect the integrity of your roof. Regular inspections, prompt repairs, and preventative maintenance will keep your roof in good condition and avoid more significant, expensive problems. Stay proactive and keep your roof—and your home—safe.

Rotted Roof Decking