Asphalt Shingle vs. Metal Roofs
Roof replacement is a major investment for homeowners in East Tennessee and a common question we get is “How long will it take?”. The timeline varies based on a few different things: roofing material, home size, roof complexity, crew efficiency, and weather conditions.
In today’s blog, we break down the time required to replace two popular roofing types—asphalt shingle roofs and metal roofs. Whether you’re planning to replace your roof or just exploring options, this post will explain the roof replacement process and help set realistic expectations.
Asphalt Shingle Roofs:
Asphalt shingle roofs, such as GAF’s Timberline HDZ or Owens Corning’s Duration, are the preferred choice for over 80% of U.S. homes, including those in Knoxville and the rest of East Tennessee, due to their affordability, versatility, and quick installation.
Here’s a detailed look at the roof replacement timeline and why speed is critical.
- Average Timeline: 1–3 days
- Factors That Can Influence Timeline:
Home Size: A typical 2,000-square-foot home with a simple gable or hip roof can take between 1–2 days. Larger homes (3,000+ square feet) or complex roofs with dormers, valleys, or steep pitches (which are very common in historic neighborhoods) may require 2–3 days. The simpler the roof design, the quicker it is to replace.
Crew Size: A professional crew of 4–6 workers can efficiently strip old shingles, inspect underlayment and install new shingles within the 1-3 days mentioned above. Smaller crews or Do-It-Yourself projects, less common in East Tennessee due to the need for expertise, significantly extend the timeline and have increased risks for incorrect installation.
Weather: East Tennessee’s unpredictable spring and summer storms can postpone or halt work altogether. GAF recommends scheduling during dry seasons to avoid delays (like early fall), as wet surfaces are unsafe for shingle installation and put the roofing crews’ safety at risk.
Installation Process:
Tear-Off (4–8 hours): Removing old shingles, underlayment, and flashing. Local regulations in Lenoir City may require off-site debris disposal, adding time to the cleanup process.
Inspection, Repairs, and Prep (2–6 hours): Checking the roof deck for rot, mold, or damaged plywood before installing new shingles, which is critical in East Tennessee with moisture damage being a frequent issue.
Installation (8–16 hours): Laying underlayment (e.g., GAF’s Tiger Paw or Owens Corning’s ProArmor), flashing, and shingles. Architectural shingles, like GAF Timberline HDZ with LayerLock Technology, are slightly faster to install due to wider nailing zones, a feature valued in Knoxville’s variable weather.
Why It’s Faster:
Asphalt shingles are lightweight, pre-cut, and installed with nail guns that require minimal customization.
Why Speed Matters:
Asphalt shingles are designed with protective “hitchhikers”, which is just a fun way to describe the extra granules/coatings that shield the water-shedding asphalt layer when bundles are opened. These extra hitchhikers help keep brand new shingles intact when roofers walk across the roof during installation. In Knoxville’s sunny summers, roofers must work efficiently and start on the shaded side of the roof, moving opposite the sun’s path to avoid the heat softening the shingles, which can lead to scuffing or granule displacement. A swift, sun-conscious installation ensures the shingles’ long-term durability when installed correctly.
Pro Tip:
Hire a crew familiar with Knoxville’s climate to ensure a fast, high-quality installation that protects your shingle’s granular layer.
Metal Roofs:
Metal roofs are growing increasingly popular for their durability and energy efficiency, however they take longer to install due to their complexity and precision requirements. Rushing a metal roof replacement or installation can lead to a plethora of problems that can cost thousands of dollars to repair.
- Average Timeline: 3–7 days
- Key Factors Influencing Timeline:
Home Size and Complexity: A 2,000-square-foot home with a simple roof takes 3–5 days. Complex roofs with multiple slopes or custom features, often seen in Lenoir City’s rural properties, can extend to 5–7 days. In storm-prone East Tennessee, precision is critical for weather resistance.
Crew Expertise: Metal roofing demands specialized skills for cutting, fitting, and sealing panels. A crew of 4–6 workers trained in metal systems is standard in the Knoxville area.
Weather: Metal can be installed in light rain, but high winds or extreme cold, common in East Tennessee winters, may slow progress
Material Type: Pre-formed corrugated panels install faster than standing seam or metal tiles, which demand precise alignment. Delivery delays for custom colors or coatings, sometimes needed for Knoxville’s aesthetic preferences, can also extend the timeline.
Installation Process:
Tear-Off (4–8 hours): Removing old materials can take a whole day. Crews must be extra careful to dispose of old roofing to avoid damaging the deck, especially for older homes.
Inspection, Repairs and Prep (4-8 hours): Inspecting decking for structural integrity and installing underlayment, insulation and vapor barriers. Metal roofs may require additional framing or purlins, common in East Tennessee’s varied roof designs.
Installation (2-5 days): Measuring, cutting, and securing metal panels or tiles. Standing seam roofs, popular in Knoxville for their sleek look, require meticulous seam crimping and flashing to prevent leaks. Custom panels may need on-site fabrication, adding time.
Why it’s Slower:
Metal roofs involve precise measurements, heavier materials, and specialized fasteners. Unlike shingles, rushing installation risks misaligned panels or improper sealing, leading to leaks—especially problematic in Knoxville’s frequent storms. Careful, deliberate work ensures watertight seams and long-term performance, with metal roofs lasting 40–70 years compared to 15–30 for shingles.
Pro Tip:
Hire a contractor experienced in metal roofing to avoid leaks from rushed work. Check online for valid permits and licenses before hiring anyone!
Comparison and Considerations
- Asphalt Shingle Roofs: Faster (1–3 days) and ideal for budget-conscious homeowners in Knoxville needing quick results. Speed protects the shingles’ granular layer, crucial in East Tennessee’s humid climate.
- Metal Roofs: Slower (3–7 days) but offer unmatched longevity and energy savings, appealing for historic homeowners prioritizing durability. Deliberate installation prevents leaks in storm-prone areas.
- Shared Factors: Both timelines assume a professional crew, no major structural repairs, and favorable weather. Issues like rotted decking, common in older homes, or permitting delays can add 1–2 days. East Tennessee’s building codes may require additional inspections which can extend the timeline of your project.
Final Thoughts:
In East Tennessee, asphalt shingle roofs are replaced in 1–3 days, with speed being critical to protect the shingles’ granular layer from sun and foot traffic. Metal roofs take 3–7 days, requiring careful installation to ensure a leak-free result in our stormy climate. For an accurate timeline, consult a licensed contractor who understands your home’s size, roof design, and local conditions.
A well-planned roof replacement with a skilled crew will deliver a durable, long-lasting roof that enhances your home’s value and protection.
–Daniel Hood
