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Guide · 2026

Can you put a metal roof over shingles?

Can a metal roof go over existing shingles?

Often, yes, over one layer of sound shingles on a solid deck. The International Residential Code does not allow a re-cover over two or more existing layers, over a water-soaked or deteriorated roof, or over slate, clay, cement or asbestos-cement tile. Local rules can be stricter.

Skipping tear-off saves about $2,460 to $7,380 on a 2,000 sq ft home.

What the building code says

IRC section R908.3.1.1 lists when a roof re-cover is not permitted:

  1. The existing roof or roof covering is water-soaked or has deteriorated so it is not an adequate base.
  2. The existing roof covering is slate, clay, cement or asbestos-cement tile.
  3. The existing roof already has two or more applications of any type of roof covering.

The code also says complete and separate roofing systems, such as standing-seam metal systems that carry the roof loads straight to the building's structure, do not require removal of the existing roof covering (R908.3.1, 2015 IRC text as adopted in Missouri).

Local rules differ. Your town adopts a code edition and can amend it. Oklahoma's rules, for example, do not allow a second layer of asphalt shingles, and IBHS says re-cover is often not permitted in moderate hail zones. Ask the building department before you sign.

What the manufacturer requires

  • A solid deck. McElroy Metal: sections with water, fire or impact damage should be removed and repaired first.
  • A separation layer. For panels fastened directly over shingles: #30 felt, synthetic underlayment or thin foil-faced insulation between the shingles and the metal.
  • Ventilation. McElroy notes that direct-over installation makes ventilation harder to build in, which trims the energy savings.

Pros and cons

For

  • Saves tear-off: $100 to $300 per square.
  • Less disposal; the Metal Roofing Alliance points to the environmental impact avoided.
  • Fewer days with the house open to weather.

Against

  • Nobody sees the deck, so rot stays hidden.
  • Ventilation is harder to build in.
  • Not allowed over two layers, tile or slate, or where your local code bans it.

Full costs: metal roof cost, and the comparison with a new shingle roof in metal roof vs shingles.

Sources for the figures on this page

Code and manufacturer guidance

  • UpCodes, R908.3.1.1 Roof Recover Not Allowed (Colorado DFPC Residential Code 2021, based on the 2021 IRC), retrieved 2026-09-28: A roof recover shall not be permitted where any of the following conditions occur: 1. Where the existing roof or roof covering is water soaked or has deteriorated to the point that the existing roof or roof covering is not adequate as a base for additional roofing. 2. Where the existing roof covering is slate, clay, cement or asbestos-cement tile. 3. Where the existing roof has two or more applications of any type of roof covering.
  • Atlas Roofing, 2021-2024 Building Codes: Roofing Provisions (cites IRC R908.3.1.1 / IBC 1512.2.1.1), retrieved 2026-09-28: A roof recover shall not be permitted where any of the following conditions occur: 1) Where the existing roof or roof covering is water soaked or has deteriorated to the point that the existing roof or roof covering is not adequate as a base for additional roofing 2) Where the existing roof covering is slate, clay, cement or asbestos-cement tile 3) Where the existing roof has two or more applications of any type of roof covering
  • UpCodes, R908.3.1 Roof Re-cover (Missouri Modular Residential Code 2015), retrieved 2026-09-28: Complete and separate roofing systems, such as standing-seam metal roof systems, that are designed to transmit the roof loads directly to the building's structural system and do not rely on existing roofs and roof coverings for support, shall not require the removal of existing roof coverings.
  • UpCodes, R908.3.1 Roof Re-cover (Missouri Modular Residential Code 2015), retrieved 2026-09-28: Metal panel, metal shingle and concrete and clay tile roof coverings shall be permitted to be installed over existing wood shake roofs where applied in accordance with Section R908.4.
  • Cornell LII, Okla. Admin. Code 748:20-6-14 (IRC 2018 Chapter 9), retrieved 2026-09-28: Where the existing roof has one or more application of asphalt shingles additional applications of asphalt shingles shall not be permitted.
  • IBHS, Roof Guide: Codes & Standards (RICOWI), retrieved 2026-09-28: There are no specific requirements for hail resistance of roofing products in model building codes. In moderate hail zones, recover of an existing roof is often not permitted (please refer to the jurisdiction having authority).
  • McElroy Metal blog, Can A Metal Roof Be Installed Over My Existing Roof? (page dated 2026-06-09), retrieved 2026-09-28: Before anything goes on top, the wood deck underneath needs to be solid. If there is water, fire, or impact damage, those sections should be removed and repaired so the new metal roof sits on a stable, secure surface.
  • McElroy Metal blog (page dated 2026-06-09), retrieved 2026-09-28: Most building codes do not allow a new roof covering over a deck that already carries two or more applications of roofing, so a house already wearing two layers of shingles usually needs a tear-off (see International Residential Code Section R908.3).
  • McElroy Metal blog (page dated 2026-06-09), retrieved 2026-09-28: Two technical notes matter here: it is hard to build in ventilation with this method, which trims the energy savings, and you must place a barrier (#30 felt, synthetic underlayment, or thin foil-faced insulation) between the old shingles and the new panels so the shingles do not wear through the metal as it expands and contracts over the years.
  • Metal Roofing Alliance FAQs, retrieved 2026-09-28: Metal roofs can often be installed over an existing roof, eliminating the environmental impact of disposal

Tear-off cost

  • HomeGuide (page dated 2026), retrieved 2026-09-25: A roof tear off costs $1 to $5 per square foot for labor to remove the old material, depending on the type and number of layers: Tearing off shingles or metal costs $1 to $3 per square foot on average. Removing heavier materials like slate or tile costs $2 to $5+ per square foot.
  • HomeGuide (page dated 2026), retrieved 2026-09-25: The cost to remove asphalt shingles is $1 to $3 per square foot, depending on the number of layers.
  • Fixr (page dated February 4, 2026), retrieved 2026-09-25: Tearing off and disposing of an old roof averages $50 per square ... [up to] $150 per square [heavier materials or multiple layers]
  • HomeAdvisor (page dated June 17, 2026), retrieved 2026-09-25: Old roofing removal runs "$1 to $5 per square foot" depending on accessibility and pitch.
  • Forbes Home, retrieved 2026-09-25: Roof removal commonly costs between $1 and $5 per square foot on average depending on the complexity of the removal.
  • RoofingCalculatorHQ (calculator methodology) (page dated May 15, 2026), retrieved 2026-09-25: Most US re-roof projects bill the tear-off line between $1.00 and $2.40 per square foot in 2026 ... A 2-layer asphalt strip costs roughly 1.9x to 2.0x a single-layer strip.

Code sections are quoted from published adoptions of the IRC; your jurisdiction's adopted edition governs. Written by the Thomas Town Digital editorial team. We match homeowners with roofers; we do not roof.

Metal over shingles questions

Can you put a metal roof over shingles?

Often, yes. The Metal Roofing Alliance says metal roofs can often be installed over an existing roof. The International Residential Code does not allow any re-cover over a roof that already has two or more layers, is water-soaked or deteriorated, or is slate, clay, cement or asbestos-cement tile.

How many layers of shingles can you put metal over?

Usually one. IRC R908.3.1.1 does not permit a re-cover where the existing roof has two or more applications of any type of roof covering, so a house with two layers of shingles usually needs a tear-off first. The code exempts complete and separate systems, such as standing seam that carries the roof loads to the structure.

Do you need underlayment between shingles and metal?

Yes, for panels fastened directly over the shingles. McElroy Metal says a barrier such as #30 felt, synthetic underlayment or thin foil-faced insulation must go between the old shingles and the new panels so the shingles do not wear through the metal as it expands and contracts.

How much does skipping tear-off save?

Tear-off costs about $100 to $300 per square for one layer of shingles. On a 2,000 sq ft single-story home (24.6 squares) that is about $2,460 to $7,380, before any deck repair a tear-off would have exposed.

Is my local code stricter?

It can be. Oklahoma's rules, for example, do not permit a second layer of asphalt shingles over an existing one, and IBHS notes that re-cover is often not permitted in moderate hail zones. Check with your local building department.