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Roof Underlayment Cost Calculator

Estimate 2026 US roof underlayment cost by line item: 15-lb felt, 30-lb felt, synthetic UDL (Titanium, RoofTopGuard, Tiger Paw), or full-coverage peel-and-stick self-adhered SBS, with eave ice-and-water shield, drip edge, starter strip, tear-off, permit and disposal. Real 2026 NRCA, ARMA and IRC R905.1.1 contractor rates.

Roof Underlayment Cost Calculator

2026 US roof underlayment cost by line item — 15-lb felt, 30-lb felt, synthetic UDL (Titanium, RoofTopGuard, Tiger Paw), or full-coverage peel-and-stick self-adhered SBS, with eave ice-and-water shield, drip edge, starter strip, tear-off, permit and disposal. Real 2026 NRCA, ARMA and IRC R905.1.1 contractor rates.

Estimated underlayment cost
$4,545
Range: $3,863 – $5,453
underlayment + tear-off + ice & water + drip edge + starter + permit + disposal
Underlayment installed
$2,195
Tear-off
$1,210
Ice & water shield
$440
Drip edge
$500
Starter strip
$0
Disposal
$200

What this calculator estimates

This calculator gives you a line-by-line 2026 US installed price for roof underlayment, the water-resistive layer that sits between the roof deck and the shingles, metal panels, tile or membrane above. Whether you are re-roofing a 1,500 sq ft starter home, replacing the deck on a 3,200 sq ft two-storey colonial, or specifying a new build to GAF Golden Pledge standards, the calculator follows the line-item structure that NRCA-member roofers use on real quotes:

  • Underlayment material — 15-lb felt, 30-lb felt, synthetic UDL, or full-coverage peel-and-stick self-adhered SBS
  • Tear-off — removing the existing underlayment and load-out to dumpster
  • Ice-and-water shield — self-adhered membrane strip at eaves, valleys and around penetrations, sized in linear feet
  • Drip edge metal — galvanised or aluminium L-shape at eaves and rakes
  • Starter strip — peel-and-stick or nail-down strip below the first course (optional but warranty-required for many systems)
  • Permit, disposal, weekend premium, and extra labour

An $850 minimum mobilisation fee applies in most US markets even on small jobs, because re-roofing requires a 2-person crew with a roof jack, magnetic sweep, dumpster placement and tarping.

How to use it

  1. Enter roof area in square feet (use the actual roof surface, not the building footprint — multiply footprint by the pitch factor: 1.06 for 4/12, 1.12 for 6/12, 1.20 for 8/12, 1.30 for 10/12, 1.42 for 12/12).
  2. Pick underlayment type — 15-lb felt for budget builds, 30-lb felt for code-minimum on lower-pitch roofs, synthetic UDL for the modern industry standard, peel-and-stick for storm-prone or historic full-coverage specs.
  3. Pick roof pitch — low (2/12 to 4/12) 1.0x, standard (5/12 to 9/12) 1.05x, steep (10/12 or higher) 1.25x for the harness, scaffolding and slowdown that steep work demands.
  4. Set scope — spot repair (20%), partial replace (50%), or full re-roof (100%).
  5. Set storey count — single-storey 1.0x, two-storey 1.18x, three-storey or higher 1.40x.
  6. Set access difficulty — easy (drive-up) 1.0x, moderate (ladder access) 1.10x, hard (cut-up roof, dormers, hoist) 1.30x.
  7. Enter ice-and-water shield length in linear feet (eave length plus valley length plus 10% for penetrations and overlaps).
  8. Enter drip edge length in linear feet (eave length plus rake length).
  9. Toggle starter strip if you want it priced separately, then enter starter length (typically eave length only).
  10. Toggle tear-off, permit, disposal, weekend premium, and any extra labour hours.

Typical 2026 US underlayment cost ranges

These ranges reflect 2026 nationwide pricing from the NRCA Cost-of-Roofing Survey, ARMA Member Survey, and Q1 2026 quotes from Houston, Atlanta, Denver, Minneapolis, Newark and Boston.

Underlayment line item (2,000 sq ft, single-storey, moderate access)2026 installed price
15-lb asphalt-saturated felt, full deck$1,000 – $1,500
30-lb asphalt-saturated felt, full deck$1,300 – $2,000
Synthetic UDL (Titanium UDL-50, RoofTopGuard II, Tiger Paw), full deck$2,000 – $2,800
Peel-and-stick self-adhered SBS, full coverage$5,000 – $7,500
Ice-and-water shield strip at eaves and valleys (200 lf)$440 – $660
Drip edge metal, galvanised, eaves and rakes (200 lf)$500 – $700
Starter strip, peel-and-stick (200 lf)$390 – $550
Tear-off existing felt and load-out (2,000 sq ft)$1,000 – $1,400
Roof permit, full re-roof$150 – $400

Add 18 percent for two-storey, 40 percent for three-storey or higher. Add 10 to 30 percent for moderate to hard access. Add 25 percent for weekend or after-hours work.

Cost drivers

Underlayment material choice. This is the single biggest variable. Felt costs less per roll but weighs more (one 30-lb roll covers 200 sq ft vs 1,000 sq ft for a 10-square synthetic roll), takes longer to fasten, tears more easily, and has a 30-day UV exposure limit before it must be covered. Synthetic UDL roughly doubles the material cost but cuts installation labour by 30 to 40 percent and provides 90 to 180 days of UV exposure tolerance — a critical factor when bad weather delays the shingle layer.

Pitch and harness time. Low-slope work (2/12 to 4/12) is fast — installers walk freely, rolls deploy quickly. Standard pitch (5/12 to 9/12) needs roof jacks. Steep pitch (10/12 and higher) requires fall-arrest harnesses, anchor points, slower deployment, and a productivity hit of roughly 25 percent. The calculator applies a 1.25x pitch multiplier for steep installs.

Tear-off and deck inspection. Tear-off is rarely optional on a re-roof. The old underlayment is brittle, tears when shingles are pulled, and the deck must be inspected for rot, sheathing rot, fastener pull-through and ridge separation. Budget $0.55 per sq ft for tear-off and an additional $1.10 per sq ft for any sheathing replacement.

Ice-and-water shield extent. Code minimum (IRC R905.1.2) is the eave detail in cold-climate zones. Best practice extends the shield up the entire valley (a 36-inch strip down each valley centerline), around chimneys, skylights and pipe boots, and up the rakes by 18 inches in coastal storm zones. A 2,000 sq ft roof with code-minimum eaves typically uses 100 to 140 lf of shield; best-practice usage runs 200 to 280 lf.

Drip edge integration. Drip edge is required by IRC R905.2.8.5 at all eaves and rakes for asphalt shingles. Spec is 26-gauge galvanised steel or 0.019-inch aluminium, 1.5-inch face minimum. The drip edge sits on top of the underlayment at the rake and below the underlayment at the eave (ice-and-water shield laps over the eave drip edge). Cost is roughly $2.50 per linear foot installed.

Permit, disposal and storey logistics. Most US municipalities require a roofing permit at $150 to $400 for re-roofs. Disposal of old material is $0.10 to $0.20 per sq ft depending on dump-fee structure. Two-storey work adds 18 percent for ladder time and material handling; three-storey adds 40 percent.

Underlayment chemistry and what makes a good product

Asphalt-saturated felt is unwoven cellulose fibre saturated with asphalt. Quality varies based on saturation rate (a 30-lb felt actually weighs about 27 lbs per square — the “30” is a legacy spec from heavier 1950s-era product) and the asphalt blend’s softening point. Modern code-listed felts meet ASTM D226 Type I (15-lb) or Type II (30-lb), or ASTM D4869 for organic-felt with improved tear strength.

Synthetic UDL is woven polypropylene or polyethylene with a slip-resistant top surface. Quality dimensions: tear strength (minimum 50 lbf per ASTM D4533), UV exposure rating, walkability (some products are dangerously slick when wet — check the ASTM D7281 friction rating), nail sealability, and lay-flat behaviour at temperature extremes. Major brands: GAF Tiger Paw, Owens Corning ProArmor, CertainTeed RoofRunner, IKO Stormtite Plus, InterWrap RhinoRoof, Titanium UDL-50.

Self-adhered SBS membrane is rubberised asphalt with a polyethylene release film. Cap-sheet quality dictates UV tolerance and walkability. Major brands: GAF StormGuard, Owens Corning WeatherLock, CertainTeed WinterGuard, IKO StormShield, GCP Grace Ice & Water Shield (the original), Henry Blueskin.

For a 25-to-50-year shingle system, specify a major manufacturer with a system-warranty-eligible underlayment, paired with a self-adhered shield at eaves and valleys.

US code references and authority sources

  • IRC R905.1.1 — underlayment requirements for asphalt shingles
  • IRC R905.1.2 — ice barrier (ice-and-water shield) at eaves in cold climates
  • IRC R905.2.7 — underlayment for asphalt shingles, lap requirements
  • IRC R905.2.8.5 — drip edge required at eaves and rakes
  • IRC R908.3 — re-roofing over existing material limits
  • ASTM D226 — Type I (15-lb) and Type II (30-lb) asphalt-saturated felt standard
  • ASTM D4869 — improved-performance organic felt underlayment
  • ASTM D8257 — synthetic underlayment standard (slip resistance, tear, UV)
  • ASTM D1970 — self-adhered modified-bitumen ice-and-water shield standard
  • NRCA Roofing Manual — installation reference, updated 2024
  • ARMA Asphalt Roofing Residential Manual — system specification reference

When each underlayment is the right choice

  • 15-lb felt — investor-grade rentals, sheds, garages, and other low-stakes installs where a 10 to 15-year shingle life is acceptable.
  • 30-lb felt — historic restorations where the look and feel of traditional felt is specified, or low-pitch residential where extra weight resists wind lift during install.
  • Synthetic UDL — virtually every modern residential and light-commercial re-roof. The default choice for any 25-year-or-better shingle system.
  • Full-coverage peel-and-stick — coastal hurricane zones, low-pitch sections (2/12 to 4/12), wildfire-overlay regions where ember-shower resistance matters, and historic full-spec restorations.

Bidding strategy and red flags

Always get three written bids that itemise underlayment brand, ice-and-water shield brand and linear footage, drip edge gauge and material, starter strip brand, tear-off scope, permit cost and dump fees. A bid that lumps “underlayment and accessories” into a single line item is a red flag. Confirm:

  1. The bidder uses the manufacturer’s branded underlayment matched to the shingle system warranty tier.
  2. The bid lists ice-and-water shield linear feet, not just “as required.”
  3. Drip edge gauge meets IRC minimum (26-gauge galvanised or 0.019-inch aluminium).
  4. The bid includes deck inspection time and a per-sheet rate for sheathing replacement.
  5. The bid identifies the foreman and crew certification (GAF Master Elite, Owens Corning Platinum, CertainTeed SELECT ShingleMaster).

For deeper estimating, also use our roof replacement cost calculator, roof tear-off cost calculator, and ice dam risk calculator to cross-check a complete re-roof bid against your specific square footage and climate zone.

Frequently asked questions

How much does roof underlayment cost installed in 2026?
In the US, installed roof underlayment runs $0.45 per sq ft for 15-lb asphalt-saturated felt, $0.60 per sq ft for 30-lb felt, $0.95 per sq ft for synthetic UDL (Titanium, RoofTopGuard, GAF Tiger Paw), and $2.50 per sq ft for full-coverage peel-and-stick self-adhered SBS. A 2,000 sq ft re-roof with synthetic underlayment, 200 lf of ice-and-water shield at the eaves and valleys, and 200 lf of drip edge, including tear-off and disposal, totals roughly $4,200 to $5,400 in 2026 NRCA Cost-of-Roofing Survey pricing. Source: NRCA Cost-of-Roofing Survey 2026; ARMA Asphalt Roofing Residential Manual; Q1 2026 quotes from Houston, Atlanta, Denver, Minneapolis and Boston.
Felt vs synthetic underlayment — which is better?
Synthetic UDL outperforms 15-lb and 30-lb felt on every measurable dimension except sticker price. Synthetic weighs roughly a quarter of 30-lb felt (one 10-square roll vs four), tears at 50 to 100 lbf compared to 8 to 18 lbf for felt, has UV exposure ratings of 90 to 180 days vs 30 days for felt, lays flat without the buckling and wrinkling that comes from felt absorbing humidity, and walks far safer in wet conditions. The cost gap is real — roughly $0.35 per sq ft material premium — but on a 2,000 sq ft roof that is $700 against a 25-to-50-year shingle warranty. Most major shingle manufacturers (GAF, Owens Corning, CertainTeed, IKO) now require synthetic underlayment for their full system warranty tiers.
Where is ice-and-water shield required by code?
IRC R905.1.2 requires self-adhered ice-and-water shield (Grace Ice & Water, GAF StormGuard, IKO StormShield) at eaves wherever the average January temperature is 25°F or lower — basically all of the northern US plus higher-elevation regions of Colorado, New Mexico, Arizona and California. The shield must extend from the eave edge to a point at least 24 inches inside the inside face of the exterior wall (typically 36 inches up the roof from the fascia for a 2x6 wall and 6/12 pitch). Best practice is to also strip in valleys, around penetrations and at low-slope-to-steep transitions. Cost is roughly $2.20 per linear foot installed in 2026 NRCA pricing.
Do I need full-coverage peel-and-stick under the whole roof?
Almost never on a sloped asphalt-shingle roof. Full-coverage peel-and-stick (sometimes called total ice-and-water) costs $2.40 to $3.00 per sq ft installed and is overkill for a typical residential pitch. It is justified in three situations: (1) low-slope sections (2/12 to 4/12) where shingles alone do not meet code, (2) historic homes in coastal hurricane zones where wind-driven rain risk is extreme, and (3) under metal roofing on tongue-and-groove decks where condensation drainage matters. For everyone else, synthetic UDL on the field plus self-adhered membrane at eaves, valleys and penetrations is the right spec.
How much underlayment do I need for my roof?
Underlayment is sold in 'squares' — one square covers 100 sq ft. Felt rolls are typically 4 squares (400 sq ft) per roll. Synthetic rolls are commonly 10 squares (1,000 sq ft) per roll, with some brands offering 20-square rolls. Always add 10% to 15% for laps, cuts, and waste — manufacturers specify a minimum 2-inch horizontal lap and 6-inch vertical lap, which adds roughly 8% to coverage. For a 2,000 sq ft roof, plan on 22 to 23 squares of synthetic underlayment, plus 2 to 3 rolls of 36-inch ice-and-water shield for eaves and valleys.
Can I install new underlayment over old?
Code allows it under IRC R908.3 only if the existing underlayment is dry, intact, well-adhered, and the total roof covering does not exceed two layers. In practice, most roofers tear off old felt with the shingles for three reasons: (1) old felt is brittle and tears when shingles are removed, (2) inspection of the deck for rot and fastener pull-through is impossible without tear-off, and (3) most shingle manufacturer warranties require fresh underlayment over a clean deck. Tear-off costs roughly $0.55 per sq ft in 2026, including dump fees.
Does synthetic underlayment qualify for shingle warranty system upgrades?
Yes. GAF Golden Pledge and System Plus warranties accept GAF FeltBuster Synthetic Roofing Felt and GAF Tiger Paw. Owens Corning Platinum Protection accepts ProArmor and Deck Defense. CertainTeed SureStart PLUS accepts DiamondDeck and RoofRunner. IKO Black Gold Premium accepts Stormtite Plus. To qualify for the upgraded warranty (typically 25 to 50 years material plus 25 years labour), you must use the manufacturer's branded underlayment, the manufacturer's branded ice-and-water shield, the manufacturer's starter strip, and the manufacturer's hip-and-ridge — installed by a certified contractor.
What is starter strip and is it the same as underlayment?
No, they are different products. Underlayment is a roll-good water barrier installed across the entire deck. Starter strip is a 7-to-9-inch peel-and-stick or nail-down strip applied along the eave edge before the first course of shingles, providing the sealant bond that anchors the leading edge against wind uplift. GAF Pro-Start, Owens Corning Starter Strip Plus and CertainTeed SwiftStart all run roughly $1.95 per linear foot installed in 2026. It is required by manufacturer wind-warranty terms for Class H 130-mph rated installations.

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