The short answer
Immediate Structural Damage
The sheathing, usually plywood or oriented strand board, absorbs water quickly. It begins to swell and warp, which can pull nails loose and compromise its ability to hold roof shingles securely. If left wet, the wood fibers permanently weaken, leading to soft spots and potential sagging. This damage is not always visible from your attic floor, hiding the true extent of the problem.
Rapid Mold Growth
Attics are prone to mold because they are often poorly ventilated and trap heat. Wet sheathing provides the perfect food source for mold spores already in the air. In a humid subtropical climate with hot rainy summers and an Atlantic hurricane season, this process accelerates. Visible mold may appear as black, green, or white speckles or streaks on the wood.
Mold releases spores into your home's air, which can cause respiratory irritation, allergies, or asthma attacks for some people. The mold colony can also spread to nearby insulation, rafters, and stored belongings. Once established, mold is difficult to remove completely without addressing the moisture source and damaged materials. A mold professional should assess significant growth for safe remediation.
- Mold can start growing in 24 to 48 hours of wetness.
- It often grows on the backside of sheathing, hidden from view.
- Musty odors in your living space can be a sign of attic mold.
- Disturbing mold without containment spreads spores throughout the home.
- Bleach does not kill mold roots in porous wood like sheathing.
- Mold can stain wood and cause permanent discoloration.
Secondary Damage to Your Home
Water from the sheathing often drips down and soaks the attic insulation below. Wet insulation loses its R-value, meaning it no longer keeps your home energy efficient. This leads to higher heating and cooling bills. The moisture can also condense on cold surfaces, leading to rust on metal ducts, nails, or electrical boxes in the attic space.
Persistent dampness can cause water to wick into the tops of interior walls, damaging drywall and paint on your ceilings. It can also promote wood rot in ceiling joists and rafters. If you live in New Orleans, this cycle of humidity and moisture can create a continuous problem. The longer the sheathing stays wet, the more expensive the repairs become.
How the Pros Dry Wet Sheathing
Local water damage pros use specialized equipment to dry sheathing from both sides. They set up high-powered air movers and dehumidifiers in the attic to create rapid air circulation and remove moisture from the air. Often, they need to create strategic ventilation openings in the roof decking to allow airflow into the cavity behind the sheathing, which home fans cannot reach.
They monitor the drying process with moisture meters to ensure the wood's moisture content returns to a safe, dry standard. Simply running a fan in the attic is usually insufficient, as it only moves surface air. The goal is to dry the sheathing in place to prevent the cost and disruption of a full roof tear-off, but sometimes replacement is necessary.
Cost Factors for Repair
The cost to fix wet sheathing depends on the extent of water exposure and how quickly you respond. A small, recent leak that only affected a few sheets may only require drying. A widespread, long-term leak that caused rot and mold often requires sheathing replacement, which involves removing shingles. The price often ranges widely, as it depends on roof size, pitch, and material costs.
Your homeowner's insurance may help cover the cost if the leak was sudden and accidental, like from a storm or burst pipe. Damage from long-term neglect or lack of maintenance is typically not covered. Policies vary, and your insurer decides what is covered. It is wise to document the damage with photos and contact your insurance agent to discuss your claim.
- The size of the affected area is the primary cost driver.
- Roof pitch and height affect labor time and safety requirements.
- The presence of mold or asbestos can add abatement costs.
- Local material and labor rates influence the final price.
- Whether just drying or full replacement is needed changes the cost.
- The need for temporary weather protection during repairs adds expense.
Water damage does not wait
Call (504) 608-0810 any time, day or night, and describe what happened.
Call Now (504) 608-0810Frequently asked questions
Can I dry wet attic sheathing myself?
For a small, fresh leak, you might use fans and a dehumidifier. However, attic sheathing is often damp inside the roof assembly where home equipment cannot reach. Without proper drying, hidden mold and rot develop. For any significant wetness, a professional assessment is wise to prevent costly hidden damage.
How long does it take for sheathing to dry?
With professional drying equipment, it typically takes two to four days for sheathing to dry thoroughly. The timeline depends on the material's thickness, the extent of wetness, and indoor humidity levels. Pros use moisture meters to confirm dryness before they stop the process, ensuring no moisture remains to cause problems later.
Will my insurance cover wet sheathing repairs?
Coverage depends on your policy and the leak's cause. Sudden, accidental damage from a covered peril like a storm is often covered. Slow leaks from wear and tear usually are not. Policies vary, and your insurer decides what is covered. Always report the damage promptly and review your policy details with your agent.