The Best Synthetic Roof Underlayment in 2026: 7 Brands Compared by Tear Strength and Price

Last reviewed: October 2026.

The best synthetic underlayment in 2026 depends on whether you are optimizing for UV exposure window, weight, walkability, system-warranty fit, or price. This comparison covers seven widely sold products (DuPont Tyvek Protec 120, GAF Deck-Armor, Owens Corning ProArmor, CertainTeed DiamondDeck, IKO Stormtite, Atlas Summit 60, Sharkskin Ultra). It is compiled from manufacturer data sheets and product literature, code evaluation documents and retail listings seen through Google Shopping on October 9, 2026. The Roofing Brief did not run hands-on tests. On the published specs, Sharkskin Ultra carries the longest UV exposure rating (12 months, per Kirsch), GAF Deck-Armor and CertainTeed DiamondDeck sit at 180 days, and IKO Stormtite is the shortest at 30 days. Atlas Summit 60 had the lowest listed roll prices, and the shingle makers’ own products fit their system warranties. For related market data, see the 2026 State of Roofing Insurance report.

Why synthetic at all (the felt comparison in two paragraphs)

Asphalt-saturated felt (15-lb and 30-lb) has been the default roof underlayment for most of the last century. For more data, see the 2026 Shingle Brand Comparison Report. It works. It is also heavy, tears easily, absorbs water (becoming heavier and weaker), buckles in heat, and gives off the smell that defines reroof day. Synthetic underlayments are polypropylene or polyethylene woven scrims with coatings, engineered to beat felt on tear strength and weight. GAF, for example, says Deck-Armor has at least 600 percent greater tear strength than standard #30 felt.

The trade-off used to be price. The gap has narrowed, and synthetic is now common on new shingle installs. Felt persists mainly in low-bid markets and in cases where the homeowner specifically requests it. For the full felt vs synthetic decision, see felt vs synthetic underlayment.

The metrics that actually matter

Marketing material on synthetic underlayment runs heavy on claims like “10x stronger than felt” or “industry-leading durability.” For lifespan context by material, see the 2026 Roofing Material Lifespan Report. The metrics that matter on the roof:

• Tear strength: resistance to foot traffic, nail miss-strikes, and wind. Makers report it with different methods (ASTM D4533 trapezoid tear is common), so compare within one test method only.
• Nail sealability: how well the membrane seals around fasteners.
• UV exposure window: how long the underlayment can sit exposed if the shingles get delayed. This is the most consistently published spec, so it anchors the table below.
• Weight (lb per square): affects shipping, handling, and installation speed.
• Wrinkle and lay-flat behavior: wrinkles can telegraph through shingles.
• Slip resistance: walking surface for installers, especially in damp or sloped conditions.
• Temperature rating: matters under metal and in hot climates.
• Warranty terms and system integration (GAF, OC and CertainTeed count their own underlayments toward some system warranty tiers).

The 7-brand comparison table

Product	UV exposure window (maker)	Roll size and weight (maker)	Listed roll price, Oct 9, 2026
Tyvek Protec 120 (DuPont)	3 months	48 in x 250 ft (10 squares), 25 lb	$100.59 to $161.99 (Arbor, Home Improvement Supply, McCoy’s)
GAF Deck-Armor	Up to 180 days	48 in wide, about 43 lb per roll (1,000 sq ft)	$141.61 (Home Depot)
Owens Corning ProArmor	Up to 90 days	42 in x 286 ft (about 10 squares), 23.5 lb	$95.00 to $137.00 (ASO Roofing Supply, Lowe’s, Menards, Arbor)
CertainTeed DiamondDeck	180 days maximum	4 ft x 250 ft (10 squares)	$217.00 to $298.78 (Arbor, S.W. Collins, Ring’s End, Home Depot)
Sharkskin Ultra (Kirsch)	12 months	1,000 sq ft roll, 27.5 lb (about 5 lb per square)	$255.00 to $450.00 (Schafer Metals, Arbor)
IKO Stormtite	30 days maximum	4 ft x 250 ft (10 squares)	$97.00 to $160.00 (Cowls Building Supply, Arbor)
Atlas Summit 60	60 days	48 in x 250 ft (10 squares)	$72.10 to $111.50 (All Roofing Supply, Home Improvement Supply, Arbor)

Sources: DuPont Tyvek Protec 120 sales sheet (K-29378); GAF Deck-Armor sell sheet (RESUL164) and product page; Owens Corning ProArmor product data sheet; CertainTeed DiamondDeck evaluation documents on the Florida Building Code product approval site; Kirsch Sharkskin Ultra architectural specifications; IKO Stormtite technical data sheet and Florida approval; Atlas Summit 60 product page. Prices are single listings that change often and exclude freight and installation. Installed cost depends on the whole roofing bid, so get the underlayment named as a line item.

Tyvek Protec 120 (DuPont)

DuPont brings its housewrap brand to roof underlayment. Tyvek Protec 120 is a four-layer synthetic with an embossed top surface that DuPont markets as having “industry-leading walkability” in dry, wet, hot, cold and dirty conditions. That is the maker’s claim; no independent walkability ranking is published.

DuPont’s sales sheet lists a 3-month UV exposure limit, a 10-square roll at 25 lb, a 30-year warranty, and use on slopes of 2:12 or more under asphalt shingle, cedar shingle and metal. For tile and slate, DuPont points to Tyvek Protec 160 or 200 instead. Listed roll prices ran $100.59 to $161.99 on October 9, 2026.

Where it fits: buyers who want a non-shingle-brand underlayment with a strong slip-resistance pitch. Where it does not: tile and slate roofs, where DuPont itself specifies a different Protec product.

GAF Deck-Armor

GAF’s premium breathable synthetic. GAF lists UV resistance for up to 180 days and says Deck-Armor has at least 600 percent greater tear strength than standard #30 felt. The system-warranty fit is the main reason to choose it: GAF’s enhanced warranties start from a GAF Lifetime shingle plus a set number of qualifying GAF accessories, and GAF roof deck protection counts toward that list. Check GAF’s current qualifying-accessory list for the tier your contractor is registering.

For homeowners installing GAF Timberline shingles on an enhanced warranty tier, a GAF underlayment is the straightforward pick. On a standard GAF warranty, the underlayment choice opens up.

FeltBuster vs Deck-Armor

GAF also sells FeltBuster, a lower-priced synthetic (Home Depot listed a 1,000 sq ft roll at $119.00 on October 9, 2026), and Tiger Paw. Compare the data sheets for UV window and tear strength, and confirm which ones count for your warranty tier.

Owens Corning ProArmor

OC’s synthetic, part of the Owens Corning Total Protection Roofing System. Owens Corning’s data sheet lists UV exposure up to 90 days, a 42 in by 286 ft roll (about 10 squares) weighing 23.5 lb, and a slip-resistant surface, and says ProArmor can go under asphalt and metal roofing.

For OC system warranty tiers (Preferred and Platinum contractor levels with OC shingles), an OC underlayment is the natural pick. ProArmor had some of the lower roll prices among the shingle makers’ products, $95.00 to $137.00 on October 9, 2026.

OC Deck Defense

OC also sells Deck Defense, listed at $122.95 to $214.34 per roll on October 9, 2026. Check its data sheet for the UV window and warranty fit before choosing between the two.

CertainTeed DiamondDeck

CertainTeed’s mainstream synthetic. Evaluation documents on the Florida Building Code product approval site list a maximum UV exposure of 180 days and approve it under asphalt shingles, wood shingles and shakes, metal, concrete tile and slate. CertainTeed’s SureStart PLUS extended warranties require an Integrity Roof System, which includes CertainTeed underlayment, so DiamondDeck is the natural fit on a Landmark or Presidential roof registered for SureStart PLUS.

Price is the catch: DiamondDeck had some of the highest listed roll prices in this group, $217.00 to $298.78 per 10-square roll on October 9, 2026. For homeowners not committed to a CertainTeed system warranty, compare it against cheaper rolls with similar UV windows.

Sharkskin Ultra (Kirsch Building Products)

Kirsch describes Sharkskin Ultra as a polypropylene-based underlayment rated for 12 months of UV exposure and thermally stable from minus 40 to 280 degrees F. That is the longest UV exposure rating in this group. Kirsch also markets its SHARK GRIP surface as the most slip-resistant roof underlayment in wet, dry or dusty conditions. That is the maker’s claim. Its specification sheet lists about 5 lb per square and a 27.5 lb roll.

The product is not tied to a shingle manufacturer, which means no system-warranty conflict in either direction, but also no shingle-maker system credit. It is the most expensive roll here at some sellers ($255.00 to $450.00 on October 9, 2026), and Kirsch’s high-temperature rating makes it suitable under metal.

Other Sharkskin variants include Sharkskin Comp, Sharkskin Ultra SA (self-adhered) and Sharkskin Ultra Radiant. For low-slope or metal applications, check which variant Kirsch specifies.

IKO Stormtite

IKO’s mainstream synthetic. IKO’s technical data sheet and Florida product approval give a maximum exposure of 30 days, the shortest window in this group, so plan to shingle promptly. Listed roll prices ran $97.00 to $160.00 on October 9, 2026. For installs paired with IKO shingles (Nordic Class 4, Cambridge, Crowne Slate), Stormtite is IKO’s own underlayment; check IKO’s warranty terms for which accessories its enhanced coverage requires.

The short UV window is the real trade-off. On a straightforward reroof that is shingled the same week, it matters little. On a job likely to sit open through weather delays, a longer-rated product is the safer choice.

IKO RoofGard

IKO also sells RoofGard-branded synthetic underlayments. Check the current data sheet for the exposure limit rather than assuming it matches Stormtite.

Atlas Summit 60

Atlas describes Summit 60 as a lightweight synthetic alternative to #15 felt with a woven polymeric scrim, a slip-resistant polymer on the bottom surface, a non-woven top surface for walkability, and 60-day UV exposure under ICC-ES AC207. It had the lowest listed roll prices in this group, $72.10 to $111.50 on October 9, 2026. Atlas also sells Summit 180 for longer exposure.

For Atlas shingle installs, check Atlas’s enhanced warranty terms for which underlayment it requires. For homeowners not committed to Atlas, Summit 60 is a low-cost option where the roof will be shingled within its 60-day window.

What the install spec should require

Regardless of brand, the underlayment spec on your roof contract should specify:

• Brand and product line (not just “synthetic”)
• Coverage area (typically full deck, except where ice and water shield substitutes at eaves, valleys, and penetrations)
• Overlap (typically 4 inches horizontal, 6 inches vertical; follow the maker’s instructions)
• Fastener type and spacing (cap nails or plastic-cap fasteners, per the maker’s instructions)
• Compatibility with the shingle manufacturer’s warranty program

The contractor’s bid should list the underlayment by name. If it says “synthetic underlayment” without a brand, ask for the brand before signing, and check that the product has a code evaluation such as an ICC-ES report or a Florida product approval.

Where ice and water shield interacts with synthetic underlayment

Synthetic underlayment is the field membrane covering most of the roof. Ice and water shield is the sticky-back self-sealing membrane covering specific high-risk areas: eaves (typically 3 to 6 feet up from the eave, beyond the projection of the interior wall plane in cold climates), valleys, around skylights and chimneys, and around penetrations.

Codes based on the International Residential Code require an ice barrier at the eaves in areas where the local building department designates a history of ice forming along the eaves. Even in warmer climates it is advisable at valleys and around penetrations.

For full ice-and-water-shield spec, see ice and water shield. For the related peel-and-stick category that bridges synthetic underlayment and ice-and-water, see peel and stick underlayment.

UV exposure window: when it actually matters

Many reroof projects are shingled the same day or within a few days of underlayment install. For those projects, any of the seven products here is used well inside its published exposure window, including IKO Stormtite’s 30 days.

UV window matters when:

• The contractor strips the roof, installs underlayment, then weather delays shingle install for days or weeks.
• Phased reroofs where one slope is done at a time over a season.
• New construction where the roof deck is underlayment-only during framing-to-finish, sometimes for months.
• Long-distance contractor backlogs during peak hail or storm-claim season.

For new construction projects with long timelines, Sharkskin Ultra’s 12-month rating, or the 180-day ratings on Deck-Armor and DiamondDeck, are genuinely useful. For more, see our new construction roofing detail guide. For a mainstream reroof shingled within the week, the UV-driven brand differences matter little.

The walkability factor

A slippery underlayment in damp conditions creates real fall risk, so walkability matters more than homeowner research usually suggests. Most modern synthetics have non-slip coatings or textures. DuPont, Kirsch, Owens Corning and Atlas all make slip-resistance claims in their product literature, but we found no independent, published walkability ranking across these brands, so we do not rank them here.

The practical step: ask your contractor which product the crew prefers to walk on, and why. A crew’s experience with a product on your roof pitch is worth weighing alongside the specs.

Where to spend extra, where to save

On listed prices from October 9, 2026, a 10-square roll ran from about $72 (Atlas Summit 60) to about $450 (Sharkskin Ultra at one seller), so the brand choice can move a 30-square roof’s underlayment material cost by up to about $1,100 (three rolls at $72 against three at $450, before overlap). The cost-benefit framework:

• Pick by UV window if the roof may sit open: Sharkskin Ultra (12 months), GAF Deck-Armor or CertainTeed DiamondDeck (180 days).
• Pick the shingle maker’s own product if you want its enhanced system warranty: GAF, Owens Corning or CertainTeed underlayment with that maker’s shingles.
• Pick a lower-priced roll (Atlas Summit 60, OC ProArmor, IKO Stormtite) for a simple gable roof that will be shingled promptly, staying inside the product’s exposure limit.
• Under metal or in high heat, pick a product rated for the temperature, such as Sharkskin Ultra.

For homeowners doing a full new-roof analysis, our how much does a new roof cost guide breaks down where underlayment fits in the total project budget. For the Class 4 IR upgrade that often pairs with a synthetic underlayment system spec, see class 4 impact resistant shingles.

FAQ

Can I install synthetic underlayment over old shingles for a lay-over?

Most manufacturer specs do not approve synthetic over existing shingles. The lay-over creates uneven substrate, traps moisture, and voids most manufacturer warranties on both the underlayment and the new shingles. Tear off the old roof first.

Does synthetic underlayment work under metal roofing?

It depends on the metal panel system and the synthetic. Some general-use synthetics are rated for asphalt shingle applications only. For metal roofing under hot conditions (standing seam in southern climates), use an underlayment rated for high temperatures, such as Sharkskin Ultra (rated by Kirsch to 280 degrees F) or Polyglass Polystick MTS. Check the data sheet for the temperature rating. For metal-specific install details, see metal roof installation.

What about cap nails vs staples for synthetic underlayment install?

Plastic cap nails or plastic cap staples are required by most manufacturer specs (and most modern codes). Bare staples or roofing nails without caps tear through synthetic underlayment in wind and rain. The cap distributes load and prevents tear-out.

Does synthetic underlayment need to be replaced when shingles are replaced?

Yes. Tear off both shingles and underlayment together. Synthetic underlayments are designed for a one-time install life paired with the shingles above; they are not rated for reuse under new shingles.

Is the cheapest synthetic underlayment worse than 30-lb felt?

Synthetics are generally marketed as stronger and lighter than felt; GAF, for example, says Deck-Armor has at least 600 percent greater tear strength than standard #30 felt. Low-priced synthetics differ most in UV exposure limits, which range from 30 days (IKO Stormtite) to 12 months (Sharkskin Ultra) among the products here, so check the data sheet. Felt can still win on price in some markets.

Bottom line

All seven synthetic underlayments here are lighter than felt and are marketed as stronger. Within the group, the published specs separate them mainly on UV exposure window: Sharkskin Ultra is rated for 12 months, GAF Deck-Armor and CertainTeed DiamondDeck for 180 days, Owens Corning ProArmor for 90 days, Tyvek Protec 120 for 3 months, Atlas Summit 60 for 60 days and IKO Stormtite for 30 days. The shingle makers’ own products fit their system warranties, and Atlas Summit 60 had the lowest listed roll prices in October 2026. For the related material decisions on the same roof, see felt vs synthetic underlayment, ice and water shield, and peel and stick underlayment. For the cost rollup that puts underlayment in context with the whole project, see how much does a new roof cost.