Roofing comparison
Metal roofing vs. asphalt shingles
Compare the two options against the same roof, base construction, installer responsibilities, warranty path, and total proposal.
- Author
- By At-Cost Roofing editorial team
- Editorial review
- Organization editorial review complete
- Dates
- Published August 31, 2026 · Updated August 31, 2026
Official records, labeled calculations, and evidence limits follow our editorial methodology.
Side-by-side evidence
Actual differences on the same criteria
Criterion
Surface and attachment
- McElroy Metal Medallion-Lok standing seam
- Concealed-clip standing-seam metal panels over the specified substrate
- GAF Timberline HDZ asphalt shingles
- Laminated asphalt shingles fastened through the published nailing area
- Why it matters
- The assemblies move, attach, and transfer loads differently.
Criterion
Slope and water design
- McElroy Metal Medallion-Lok standing seam
- Medallion-Lok publishes a 3:12 minimum slope and requires system-specific seams, underlayment, trim, and transitions
- GAF Timberline HDZ asphalt shingles
- HDZ is a steep-slope water-shedding shingle system with named deck protection, leak barrier, starter, and ridge options
- Why it matters
- Material alone does not describe seams, secondary drainage, edges, or penetrations.
Criterion
Impact record
- McElroy Metal Medallion-Lok standing seam
- Named product record publishes UL 2218 Class 4
- GAF Timberline HDZ asphalt shingles
- Qualifying current packages publish Class 3
- Why it matters
- The exact tested products differ, but neither classification is a hail warranty.
Criterion
Project evidence: future service
- McElroy Metal Medallion-Lok standing seam
- The ownership file should retain matching panel, finish, fabricated-trim, and service records
- GAF Timberline HDZ asphalt shingles
- The ownership file should retain matching shingle, color, accessory, and service records
- Why it matters
- At-Cost comparison method: obtain the repair-material and service plan locally because national product pages do not establish future DFW stock or contractor availability.
Criterion
Project evidence: appearance and price
- McElroy Metal Medallion-Lok standing seam
- Record the actual rib profile, seam layout, finish, trim, and complete installed quote
- GAF Timberline HDZ asphalt shingles
- Record the actual dimensional pattern, color, ridge profile, accessories, and complete installed quote
- Why it matters
- At-Cost comparison method: use real samples and matched bids; the assigned national records do not establish a universal cost or service-life winner.
Put both bids on the same baseline
Compare complete assemblies from deck to finished surface. Metal needs a named panel, substrate, finish, attachment, trim, engineering responsibility, and service plan; asphalt needs the named shingle and accessory system.
Advantages and drawbacks
- McElroy Metal Medallion-Lok standing seam advantages: A named concealed-clip standing-seam panel with published panel geometry, slope boundary, substrate and finish options, tested assemblies, and Class 4 impact record.
- McElroy Metal Medallion-Lok standing seam drawbacks: Custom trim and concealed attachment demand metal-specific detailing and installation records; the sources do not establish local price, service access, or a universal service-life advantage.
- GAF Timberline HDZ asphalt shingles advantages: A named laminated asphalt shingle with current application instructions, qualifying Class 3 packages, and a defined GAF accessory and warranty path.
- GAF Timberline HDZ asphalt shingles drawbacks: The shingle record does not establish a universal cost or service-life advantage, and qualifying package, accessory, ventilation, installer, and supply conditions still control the result.
Choose McElroy Metal Medallion-Lok standing seam when
Choose Medallion-Lok when its panel profile, tested attachment, custom details, installer, future service plan, appearance, and complete quote fit the house.
Choose GAF Timberline HDZ asphalt shingles when
Choose HDZ when the steep-slope shingle system, GAF accessories, repair supply, installer execution, appearance, and complete quote fit better.
Choose neither when
Choose neither until both bids name deck work, water-control layers, edges, penetrations, ventilation, tested attachment, repair materials, closeout records, and current local pricing.
What this comparison cannot decide
Lifespan and noise slogans skip the assembly. Deck, underlayment, ventilation, attic conditions, attachment, flashing, and maintenance determine what either roof will be like to own.
Evidence boundary
The named McElroy and GAF records document materially different steep-slope products and assembly requirements. They do not supply a universal lifespan, noise, cost, maintenance, or resale verdict; compare roof-specific details, installers, service access, and complete local bids.
Common questions
Answers to check before you decide
What must match before comparing Metal roofing vs. asphalt shingles?
At-Cost comparison method: Compare complete assemblies from deck to finished surface. Metal needs a named panel, substrate, finish, attachment, trim, engineering responsibility, and service plan; asphalt needs the named shingle and accessory system.
What can this comparison not decide?
At-Cost comparison boundary: Lifespan and noise slogans skip the assembly. Deck, underlayment, ventilation, attic conditions, attachment, flashing, and maintenance determine what either roof will be like to own.
Keep reading
McElroy Medallion-Lok standing-seam review
This review covers McElroy Metal Medallion-Lok, a residential snap-lock standing-seam panel with concealed clips.
Related guideGAF Timberline HDZ review
GAF Timberline HDZ is an architectural shingle with LayerLock, a package-qualified Class 3 rating, and system-dependent wind and algae terms.
Related guideGAF Timberline UHDZ review
GAF Timberline UHDZ is primarily an appearance and package-qualified Class 4 option over HDZ, using Dual Shadow Line and UltraMat technology.
Related guideAsphalt shingle roof cost
Ask for squares of field shingles plus separate starter and ridge quantities.