Should Old Roofing Felt Be Removed or Replaced

The decision to remove old roofing felt hinges on its condition, the type of roof, and the planned roofing system. Old felt can still provide a moisture barrier when intact, but deterioration, wrinkling, or mold can compromise performance and future roofing work. This article explains when removal is advisable, when re-covering might suffice, and how to approach safety, costs, and disposal. It is tailored for a U.S. audience and emphasizes practical, actionable guidance for homeowners and contractors.

Key Considerations For Removing Old Roofing Felt

Removing old roofing felt is not automatically required. The need is influenced by underlayment condition, the roof type, and the intended new roofing system. If the felt is dry, intact, and compatible with the new roof, some crews opt to preserve it. Conversely, signs of damage or moisture intrusion often justify removal to ensure a clean, dry surface for the new layers.

Assess The Condition Of The Existing Underlayment

Begin with a thorough inspection of the existing felt and roof deck. Look for:

• Moisture damage or staining
• Warping or buckling of the underlayment
• Dry rot or compromised deck boards
• Mold or mildew growth
• Past repairs that indicate systemic issues

If the felt is fragile, moldy, or has hidden moisture beneath, removal is usually warranted. When the underlayment is in good condition and the new roof is compatible, re-covering may be acceptable under local building codes and manufacturer guidelines.

When It Makes Sense To Remove

Removal is commonly recommended in these scenarios:

• Roof deck replacement or significant deck repairs are planned, requiring a clean surface.
• Shingle or membrane change that demands a freshly prepared base for optimal adhesion.
• Evidence of moisture intrusion or structural damage beneath the felt.
• History of leaks around penetrations or along valleys that warrants renewed sealing.

Removing old felt can help ensure proper installation of flashing, ventilation, and new underlayment, reducing the risk of hidden defects compromising the new roof.

When You Can Keep The Old Felt And Re-Cover

There are cases where keeping the existing felt is acceptable:

• High-quality, compatible underlayment with the new roof system and manufacturer approval.
• Solid deck condition and no moisture history, enabling a clean, flat surface for the new installation.
• Preservation of insulation value and a need to minimize disruption and cost.

Always verify with the roofing material manufacturer and local building codes. Some systems require a specific underlayment type or installation order that may necessitate removal.

Safety, Inspection, And Disposal

Safety is paramount during removal or re-cover work. Key steps include:

• Wear protective gear (gloves, eye protection, a dust mask or respirator for mold).
• Secure fall protection for ladder use and roof access.
• Dispose of old felt properly according to local regulations; some areas treat it as construction waste or require special handling if moldy.
• Inspect the deck surface after removal to catch any hidden damage or rot early.

Professional contractors typically perform a deck inspection and may offer disposal or recycling options for the old felt.

Cost And Time Implications

The choice between removal and re-covering affects costs and project duration. Typical considerations include:

• <strongLabor costs for removal, debris cleanup, and disposal.
• <strongMaterial costs for new underlayment, sealants, and flashing.
• <strongDeck repairs if damage is found during removal.
• <strongPermits and inspections if required by local codes.

Removal generally increases upfront costs but can save long-term expenses by preventing ongoing moisture issues. Re-covering might reduce time and material costs but risks undiscovered problems surfacing later.

Alternatives And Best Practices

To balance performance and cost, consider the following best practices:

• <strongConsult Manufacturer Guidelines for underlayment compatibility with the new roofing system.
• <strongPlan For Ventilation during and after installation to avoid moisture buildup under the roof.
• <strongUse Quality Fasteners and proper spacing to ensure long-term integrity of the new layers.
• <strongDocument Moisture History with photos and notes to support future maintenance decisions.

In some cases, a hybrid approach—removing only sections around penetrations or known problem areas—offers a practical compromise.