synthetic roofing underlayment

3-months UV-logo-colour
FT-pro20-on roof


PRO20 is builder grade steep slope roofing underlayment that is cost effective and a reliable #15 felt replacement. It is easy to manage and install.Covers 2.5X more than the #15 felt. PRO20 provides a wrinkle-free surface that lays flat, and stays put with its underside non-slip coating. It can be used under; primed cedar, asphalt or synthetic shingles, and residential metal roofing. PRO20 meets and exceeds all required industry standards.

  • Fiber grip non-woven slip resistant walking surface
  • 90 day UV resistant
  • 20 year limited warranty
  • 2.5X more coverage per roll as compared to traditional #15 felt
  • 100% Recyclable water resistant polyolefin construction
  • Water resistant – 10 Mils thickness
  • Wrinkle free and low temperature flexibility for ease of installation

FT Synthetics PRO20 Meets or exceeds the following code standards:
ASTM D226-97, ASTM D4869, CAN/CSA A123.3, FBC #FL22692, CAN/CSA A220.1, ASTM E108, CCRR 1028, AC 188, TDI, Miami-Dade NOA #: 19-0820.01 and California Building Code Compliance.

WIDTH42″ (1.07 M)
LENGTH286′ (87.2 M)

Test and StandardFT SYNTHETICS PRO-2015 Lb. Felt
Material Composition
Breaking Strength ASTM D 5034 MD
101 lb (46 kg)NA
Breaking Strength ASTM D 5034 CD
96 lb (44 kg)
Tear Strength ASTM D4533 MD
25 lb (11 kg)NA
Tear Strength ASTM D4533 CD
23 lb (10 kg)
Water shower Exposure ASTM D 4869
Permeability ASTM E96
6 Perms
Nominal Thickness ASTM D1777 
10 mils
21 mils
Temperature Range 
-40°F to 240°F
Mullen Burst
102 psi
The Data shown above is based on the test averages and independent test reports. There can be a +/-10% variation in the individual test results. This report should not be considered as a warranty for the manufacturer. The manufacturer is not responsible for the misrepresentation or misinterpretation of the data by the reader. Please find out more about the product by calling 1-844-Flextex or visit www.ftsyn.com

Installation Instructions:                                                       Rev Sept 18, 2020

USE: FT PRO-20 is a contractor grade synthetic roofing underlayment designed for use in steep slope roofing as a secondary layer of protection. It is approved for installation over plywood or OSB roof decking with proper fasteners on roof slopes 2:12 and greater. FT PRO-20 is an air, vapor, and water barrier with <1 Perm and therefore should be installed above a properly ventilated space(s). FT PRO-20 replaces the use of #15 or #30 organic roofing felt and is designed for use under primary roofing materials such as asphalt or synthetic shingles, and residential metal.

DECK PREPARATION: FT PRO-20 should be installed over a clean, smooth, and dry deck. The deck should be structurally sound and should not have any voids, protrusions, damaged or unsupported areas. For re-roofing projects, replace any water damaged sheathing and sweep roof deck thoroughly removing dust, dirt and loose nails. Do not install over old roof covering.

FASTENERS: For best performance and extended exposures greater than 1 day and up to 90 days FT PRO-20 should be installed with 1” diameter plastic or metal cap, corrosive resistant, roofing nails with 1” leg or greater (ring shank preferred), or 1” diameter plastic cap staples.

If FT PRO-20  is to be covered same day by primary roofing and no driving rain or high wind events are expected it can be installed with un capped staples or corrosive resistant 3/8” head roofing nails with 1” leg or greater (ring shank recommended). Note: Use of un-capped fasteners may result in blow off or leakage around fastener penetrations during a rain or high wind event.

For coastal areas and extended exposure conditions where driving rain or strong winds are expected it is recommended to take additional precautions such as doubling lap widths, adding an adhesive on overlaps, and/or taping all roof deck seams and/or underlayment overlap seams including the perimeter edges of the roof.  For taping roof deck seams and perimeter edges consider FT Copperhead butyl roofing tape.  For adhesive use a low solvent plastic roofing cement meeting ASTM D-4586 Type 1 or Federal Spec SS-153 Type 1, such as Karnak, Henry, DAP or equivalent.

APPLICATION:  For slopes 4:12 and greater FT PRO-20 underlayment is to be installed  horizontally (parallel to the eave) with the printed side up using the provided lap lines.  Use 6” vertical laps and 4” horizontal laps. Underlayment to be installed in shingle lap fashion starting at the bottom edge of the roof deck to ensure that the water runs over the overlaps without getting under the material. Align the underlayment to the edge of the rake and eaves. FT PRO-20 should be applied under the metal drip edge along the rakes and over the metal drip edge along the eaves unless otherwise specified by local building codes.  Do not fold FT PRO-20  over the roof edge unless this edge is to be subsequently covered over by a drip edge or other flashing material. Note: All end laps of succeeding courses should be offset by a minimum of 6 feet. FT PRO-20  to be fastened using the nail pattern as printed on the product. All anchoring must be performed snug and hammered flush and at 90 degrees to the roof deck, ensuring the material surface is held tightly with the roof deck. Do not install fasteners over unsupported areas/voids. Extend product a minimum of 12” past all hips and valleys, and lap up onto walls and abutments a minimum of 8”. For batten secured installations use appropriate length ring shank nails or screws to secure battens to the roof deck, staples are not recommended. Do not install battens over cap nails.

For low slope applications between 2:12 and 4:12 it is recommended to cover the roof deck with two layers of FT PRO-20. Begin by installing a 21” wide strip along the eave with minimal fasteners. Then cover with a full 42” width of FT PRO-20.  Then overlap each successive course by 50% plus 1 inch. Vertical lap requirements are the same as in 4:12 and greater slopes. Note: Product is not recommended for slopes less than 2:12. 

If installing an ice and water protection barrier it should be installed first along the eaves and in the valleys.  It is recommended to use an ASTM D1970 approved waterproof membrane such as FT Platinum HTSA or Komodo BSA.  For additional rake edge waterproofing apply a minimum 6” strip of adhesive backed roofing seam tape flush to the rake edge on top of the FT PRO-20, then install the metal drip edge.  Consider using FT Copperhead butyl roofing seam and flashing tape.

FT PRO-20 has 90 Day UV protection and is not designed for indefinite outdoor exposure.  It is therefore recommended that installation of the primary roofing material be installed within 90 Days.

CAUTION – Read Good Safety Practice Below

As with any roofing product, always follow safe roofing codes & practices (OSHA) and always use and wear fall protection devices when working on roofs. Release liners are slippery and should be removed from work area immediately after application. Use caution when walking or standing on FT PRO-20  as slip resistance may vary with surface conditions, weather, footwear and roof pitch. Failure to use proper safety gear and footwear can result in serious injury.

Ft-pro-20- your-logo-here-black-white

PRO20 Dual logo program

PRO20 Dual Logo Program is an easy marketing tool  and receive majority branding alongside our own logo and contact information. You’ll be recognized in the community as a leader in sustainable roofing practices and gain valuable exposure for your business.

Call Now Button