Re Sheathing a Roof: Complete Guide to Roof Deck Replacement and Costs

Re sheathing a roof is the process of replacing the roof decking beneath shingles or other coverings to restore structural integrity, improve weather resistance, and prepare for new roofing. This guide explains when re-sheathing is necessary, materials and methods, step-by-step work, costs, permits, and tips for hiring contractors and inspecting the finished roof.

Item	Typical Range
Cost Per Square Foot	$1.50 – $4.50
Average House (2,000 sq ft roof)	$3,000 – $9,000
Common Sheathing Materials	OSB, Plywood, Tongue-and-Groove
Typical Project Time	1 – 5 Days

When Re Sheathing A Roof Is Necessary

Re-sheathing becomes necessary when the roof deck has significant damage from rot, water intrusion, structural movement, or has deteriorated due to age. Signs include sagging roof lines, soft or spongy decking underfoot in the attic, widespread nail pops, and visible mold or rot.Localized damage from leaks may only need spot replacement, while pervasive issues require full re-sheathing to ensure long-term performance.

Common Causes Of Roof Deck Failure

Roof deck failure can result from several causes that often interact. Long-term roof leaks, ice dams, poor attic ventilation, previous improper installations, and pest damage are frequent contributors. Additionally, excessive loads from snow or contractors walking on weakened decks can accelerate failure. Identifying the root cause is vital to prevent recurrence after re-sheathing.

Materials Used For Roof Sheathing

Choice of material affects cost, performance, and code compliance. The most common materials are oriented strand board (OSB) and plywood; older homes may have tongue-and-groove planks. OSB is typically cheaper, while plywood is more moisture-tolerant and preferred in high-humidity climates.Thickness usually ranges from 1/2″ to 5/8″ for rafters spaced 24″ on center and 3/8″ to 1/2″ for 16″ spacing, following local code requirements.

Preparing For Re Sheathing

Preparation involves inspection, obtaining permits if required, and protective measures. An experienced contractor will inspect attic framing, existing decking condition, chimney and flashing details, and ventilation systems before starting.Homeowners should clear attic spaces, secure pets, and plan for temporary water protection if weather delays occur during the project.

Step-By-Step Roof Re Sheathing Process

This section summarizes a typical workflow executed by professional roofers. Steps include removing existing roofing materials, removing old sheathing, inspecting and repairing framing, installing new sheathing, adding underlayment, and reinstalling flashing and roofing cover.Each step requires attention to fastening patterns, board alignment, and allowance for expansion and ventilation gaps.

Remove Existing Roofing

Removal begins with shingles, underlayment, and any loose flashing. Complete tear-off to the deck is required when the deck is compromised or when local code prohibits layering.Proper disposal and recycling of old materials should be arranged in advance.

Deck Removal And Framing Repair

Damaged decking is removed back to sound framing. Roofers inspect rafters or trusses for rot, insect damage, or warping and replace or sister members as needed.Repairs are critical to provide a continuous, solid nailing base for new sheathing.

Installing New Sheathing

New panels are installed with recommended fastener patterns and spacing from the manufacturer and local code. Careful staggering of joints, use of adhesive when required, and proper edge support reduce squeaks and improve wind performance.Gaps for expansion and alignment at penetrations must be maintained.

Underlayment, Flashing, And Final Roofing

Once sheathing is complete, a weather-resistant underlayment and new flashing around chimneys and valleys are installed. Proper underlayment and step flashing help prevent future leaks and are essential before shingle or metal roofing installation.Roofing is then installed per chosen material specifications.

Cost Factors And Budgeting

Costs vary by material, roof complexity, accessibility, local labor rates, and extent of framing repair. Key cost drivers include square footage, steep slopes, multiple roof planes, replacement of skylights or flashings, and local permit fees.Obtaining multiple detailed quotes and a written scope reduces surprises.

Typical Cost Breakdown

Category	Approximate Cost
Labor	40% – 60% of total
Materials (Sheathing & Underlayment)	25% – 45% of total
Disposal & Permits	$200 – $1,000+
Framing Repairs	$200 – $2,000+ depending on extent

Permits, Codes, And Inspection

Most U.S. jurisdictions require permits for structural roof work. Permit requirements and building codes dictate sheathing type, thickness, fastening, and ventilation; inspections may be required at key stages.Contractors typically obtain permits but homeowners should confirm that permits and final inspections are part of the contract.

Hiring A Contractor And Ensuring Quality

Selecting a qualified contractor reduces risk. Look for licensed, insured roofers with positive local reviews, clear warranties, and detailed written estimates that specify materials, fastening patterns, and cleanup.Request references and verify past work similar in scope. A reliable contractor will provide a production schedule and protection for landscaping and property.

DIY Considerations And Safety

While experienced DIYers may handle small patch sheathing jobs, full re-sheathing is labor-intensive and can be dangerous. Working at height, removing old materials, and ensuring structural repairs to code make professional work advisable for most homeowners.If DIY is chosen, secure proper safety equipment, permits, and inspections.

Ventilation, Insulation, And Preventing Future Damage

Re-sheathing is an opportunity to correct ventilation and insulation issues that contributed to prior damage. Ensure adequate intake and exhaust ventilation, proper attic insulation, and continuous air barriers to reduce moisture buildup and ice dam risks.Addressing these elements extends roof life and improves energy efficiency.

Inspection Checklist After Re Sheathing

After work completion, perform or request a walk-through and inspection. Key checkpoints include flat, tight sheathing installation, correct nail pattern, sealed penetrations, proper underlayment, and correct flashing installation.Confirm warranty terms on labor and materials are documented.

Common Questions And Practical Tips

Common homeowner questions include how long re-sheathing takes, whether it should be done during certain seasons, and how it affects warranties. Most projects finish in one to five days; drier months reduce weather risk, and re-sheathing typically does not void shingle manufacturer warranties when performed properly.Document the work with photos and keep receipts for future resale value.

Key Takeaways For Homeowners Considering Re Sheathing

Re-sheathing restores the roof’s structural base, prevents recurring leaks, and provides a reliable platform for new roofing. Prioritize thorough inspection, correct material selection, proper fastening, and ventilation improvements to maximize longevity and protect the home investment.

For accurate local costing and code requirements, consult a qualified roofing professional and verify permit rules with the local building department.