Understanding roofing costs broken down by individual parts and design elements empowers homeowners to budget realistically, prioritize investments, and avoid surprises. Whether you’re managing a project in Ballwin, MO, Swansea, IL, or across the country, this guide explains what each roof component costs, how design complexity influences pricing, and why accuracy matters.
Key Roofing Components and Their Costs
A roof involves multiple parts, each with its own price tag and installation demands:
Roofing Materials (Shingles, Metal Panels, Tiles)
Typically the biggest chunk of the cost. The roof-covering itself dominates the budget.
Underlayment & Ice & Water Shield
Essential for leak protection. Expect costs between $50 and $150 per square installed.
- Cost per roll: $50–$100 for standard underlayment, $80–$150 for premium ice & water shield.
- Coverage: One roll covers roughly one square.
- Installed Price per Square: $50–$100 (standard) / $80–$150 (premium).
Roof Decking (Plywood or Boards)
If rotten or damaged, replacing costs around $70–$100 per plywood sheet. This results in $200 to $400 per square installed.
- Sheet size: 4’ x 8’ = 32 sq ft per sheet.
- Sheets per square: 100 ÷ 32 = 3.125 sheets.
- Cost per sheet installed: $70–$100.
- Installed Price per Square: $219–$313.
Tear-Off & Disposal
Removing old roofing layers typically costs $100–$150 per square.
- Labor + dumpster fees: $35–$50 per hour for crew, plus disposal costs.
- Installed Price per Square: $100–$150.
Flashing, Drip Edge, Ridge Caps, Vents, Gutters
These accessories add vital waterproofing and finishing touches—even a modest total can add up, making underestimation risky. Total accessory cost per square ranges between $23–$43 on average, depending on roof design complexity.
- Flashing – $2–$5 per linear foot (materials), $5–$10 per square installed
Protects seams and transitions like chimneys, valleys, and sidewalls. - Drip Edge – $1–$2 per linear foot (materials), $3–$5 per square installed
Prevents water from seeping into fascia and roof edges. - Ridge Caps – $1–$2 per linear foot (materials), $5–$8 per square installed
Seals the roof peak to protect against wind-driven rain. - Roof Vents – $20–$50 each (materials), $5–$10 per square installed
Provides attic ventilation; per-square cost assumes 1 vent per 2–3 squares. - Gutters – $4–$9 per linear foot (materials), $5–$10 per square installed
Often replaced with a roof project to ensure proper drainage.
???? Flashing might seem like a small cost, but it’s critical to your roof’s performance. Learn more in the Importance of Replacing Roofing Flashing.
Structural Supports
Certain designs (e.g., tile or slate) can necessitate reinforced structures—especially relevant in areas like Chesterfield, where tile may be popular. This can add up to $50–$150 per square installed for reinforcement labor/materials
How Design Complexity Affects Cost
Roof design isn’t just for aesthetics—it significantly impacts labor and material costs:
Simple Gable Roofs
Cost-efficient to install with fewer components and minimal flashing.
Complex Roofs (Dormers, Valleys, Multiple Levels, Skylights, Chimneys)
Require extra materials, cuts, taping, and labor—often 25–50% more expensive.
Accessibility
Steep slopes or limited access areas increase labor time and safety overhead.
???? Labor rates can vary just as much as design choices. See our Roofing Labor Costs in 2025: Complete Pricing Guide to understand the labor side of the equation.
National Pricing Snapshot for Parts & Installation
Here’s a national view of costs per square (100 sq ft):
| Component | Estimated Cost per Square |
| Roofing Material (basic) | Varies widely; material dominates share |
| Underlayment/Ice & Water Shield | $175–$375 |
| Decking Replacement | $200–$400 |
| Tear-off & Disposal | $100–$150 |
| Flashings, Vents, Gutter Costs | Varies; part of accessory line items |
| Labor (overall installation) | ~60% of total cost |
Rate Variations by Material Type
Different materials have distinct cost and installation profiles:
Asphalt Shingles (Standard 3-tab & Architectural)
Most affordable, common; 3-tab materials cost $150–$200 per square, with total installed cost around $425 per square.
Metal Roofing
Durable and energy-efficient; typically a higher material cost, but yields savings over time with up to 40% reduction in cooling costs, especially useful in regions like Missouri. The total installed cost is usually between $700 and $1,500 per square.
???? Trying to decide between asphalt shingles and metal roofing? Our Metal Roofing vs Shingles guide lays out the pros, cons, and pricing differences.
Tile or Slate
Premium aesthetics and lifespan, but heavy and costly—total installed cost of tile ranges $700–$2,500 per square, requires framing reinforcements.
Flat Roof Membranes (EPDM, PVC, TPO)
Lower cost for commercial or flat residential applications; EPDM installs at about $400–$1,000 per square.
Green Roof Systems
High upfront cost ($10,800–$35,500 per square), but longevity and energy savings offset over time.
???? Cost isn’t everything—lifespan matters too. See how different materials stack up in our Roof Lifespan Comparison.
Local Cost Considerations: Missouri & Illinois
Homeowners in Chesterfield, O’Fallon, Belleville, etc., often see:
- Slightly lower tear-off costs than national averages.
- Materials are priced similarly to national, but design complexity in larger homes can raise accessory and labor charges.
- Incentives (e.g., for energy-efficient or metal roofs) may impact net material cost.
???? Local contractor rates also play a big role in final pricing. Check out our Roofing Contractor Fees: What Homeowners Need to Know for a detailed breakdown.
Building an Accurate Estimate: A Step-by-Step Approach
- Calculate Roof Area (adjusted for pitch).
- Identify Design Complexity (count dormers, valleys, skylights).
- Assign Component Costs:
- Material (choose type and quality)
- Underlayment & Ice Shield
- Decking (if repairs are necessary)
- Tear-off/Disposal
- Flashing/accessories
- Factor in Labor (~60% of total material+accessories cost)
- Add Contingencies (e.g., unexpected deck repairs).
- Compare Quotes between estimates, focusing on line-item transparency.
???? The right contractor can help you get the most out of your roof design and budget. Learn what to look for in What to Research When Choosing a Roofing Contractor.
Tailored Design Means Predictable Pricing
Roof costs aren’t one-size-fits-all—it’s about understanding how each part and architectural detail adds up. Whether you’re exploring asphalt shingles, tile aesthetics, or energy-smart metal, knowing the cost breakdown empowers you to make informed choices.
Ready for a Custom, Transparent Estimate?
At Gorilla Roofing, we pride ourselves on delivering top-notch roofing services with integrity and professionalism. Our team is licensed, insured, and committed to exceeding your expectations.
???? Call us today at (636) 295-1212
???? Request a FREE roofing estimate
For detailed pricing based on your unique roof design, contact Gorilla Roofing for clarity and craftsmanship you can trust.