EasyLay™ UDL SA

EasyLay UDL SALeakBarrier® EasyLay™ UDL SA is a state-of-the-art roof underlayment that combines the salient features of a synthetic membrane with revolutionary self-adhesive technology in order to deliver exceptional long-term weather barrier performance. Manufactured using a multi-laminate configuration consisting of non-woven poly fabric, UV stabilized polyolefinic coating, and woven poly scrim that provides a non-abrasive surface with good walkability, EasyLay UDL SA has an aggressive self-adhesive modified bituminous compound on the back side that is self-sealing around nails and can adhere to a variety of substrates.


EasyLay UDL SA can be used in shingles, shake, slate, tile, and metal roofing applications. Designed for use in steep-slope roofing, it can be utilized in new roofing and re-roofing applications as well. EasyLay UDL SA is ideal for use in high temperature environments.

Features and Benefits

  • Specially formulated SBS compound with 240°F temperature rating
  • High tensile and tear strengths
  • Excellent UV performance – 6 month exposure rating
  • Anti-slip coated surface provides good walkability
  • Very pliable; easily conforms to rooftop peaks and valleys
  • Superior flexibility at low temperatures – does not split or crack
  • Excellent wind resistance – Eliminates roof blow offs
  • Pre-printed lay lines for easy installation
  • Suitable surface for foam application of tiles
  • Adheres to a variety of substrates
  • Instant watertight laps
  • Self-seals around nails
  • 30 Year limited warranty
  • Meets ASTM D1970


  • EasyLay UDL SA must be stored in a dry location.
  • Rolls must be stored on ends only. Do not store in a leaning position.
  • Rolls must be stored on pallets and not more than one pallet high.
  • Do not store rolls in direct sunlight.

General Precautions

  • EasyLay UDL SA shall be installed in strict compliance with manufacturer’s guidelines and applicable Building Code.
  • Follow Occupational Safety and Health Administration (OSHA) safety standards; use common sense measures and adequate precautions to prevent accidents.
  • EasyLay UDL SA must be installed only when material interface temperatures (air, deck, material) are 40° F and rising.
  • Do not install when any form of moisture such as water, ice, snow, dew, rain, etc. is present.
  • Ensure roof has proper slope and drainage prior to installation.
  • EasyLay UDL SA is considered a vapor barrier. Proper ventilation is critical. Ensure installation does not interfere with existing ventilation.
  • When applying directly over the entire roof deck, the roofing system must provide sufficient ventilation.
  • A full, irreversible adhesion is achieved when the underlayment goes through complete heat cycles. Do not attempt to remove the underlayment immediately after adhesion to the substrate.
  • Use of a hand held “hot air gun” might help enhancing adhesion during application of underlayment in cooler weather.
  • All tiles shall be staged (two tiles perpendicular to slope, four tiles on top parallel to slope), not to exceed 6 high. When installing flat tiles and lugged tiles above 6:12 roof pitch, tiles shall be staged behind a nominal 1” x 2” horizontal batten.
  • EasyLay UDL SA shall not be torched or hot mopped to.
  • EasyLay UDL SA must be covered with an approved finished roof covering within the specified exposure time of the product. Refer to section on Features and Benefits for exposure times.

Surface Preparation

  • Surface must be clean, dry and without voids that may interfere with adhesion. Consult applicable Technical Bulletins at the Tarco website prior to installation.
  • All loose materials, debris or pre-existing membrane must be removed prior to installation.
  • Surface may be primed with an ASTM D41 Primer, Water-based Acrylic Primer, or Water-based Polymer-Modified Primer prior to installation of EasyLay UDL SA. When primer is used, ensure the primer is fully dry prior to application of EasyLay UDL SA.


  • Cut the EasyLay UDL SA roll to suitable, manageable lengths before installation.
  • Apply an ASTM D41 primer, water-based acrylic primer or water-based polymer-modified primer over the eave and rake metal drip edges extending onto the deck surface where the roll will intersect.
  • Place a full width piece of the pre-cut EasyLay UDL SA underlayment onto the approved substrate, parallel to the eave (low) edge of the roof.
  • Align EasyLay UDL SA so that it is parallel with the edge of the eave and extend over the eave and/or rake approximately 3/8”.
  • Fold back the sheet, and carefully remove the exposed release film, taking care not to displace the sheet.
  • Working from the center out, roll the sheet onto the substrate, taking care to avoid wrinkles and ridges EasyLay UDL SA must be set straight. Repeat this process for the other half of the sheet once the remaining release film has been removed.
  • On slopes greater than 2:12, install capped or tin tagged nails 6” on center in the side lap area 1½” from the edge, in the middle of the side lap area or fasten according to applicable Building Codes after the EasyLay UDL SA has been applied and prior to the overlapping of the next course.
  • Apply the next eave course in the same manner as described overlapping the first course at the end lap by a minimum of 6”.
  • Apply a 1/8” thick layer of a trowel grade SBS modified bitumen asphalt adhesive/flashing cement at the T-joint (area where an end lap and the next succeeding course intersect) for slopes less than 2:12.
  • Stagger all end laps a minimum of 18” for slopes 2:12 and greater, and 36” for slopes less than 2:12 from the preceding course.
  • Lap the succeeding course over the side lap area for 3” or as per applicable Building Code.
  • Apply pressure to the entire surface of the membrane during installation. Pressure is to be applied vertically and horizontally throughout the entire area of the membrane. A minimum of a 28 lb weighted roller shall be used for application on slopes up to 6:12 pitch. The use of a soft bristled push broom is acceptable on steeper slopes (> 6:12 pitch). Pay special attention to side lap, end lap, T-joint, eave and rake edges during the application of pressure to ensure contact and adhesion. This procedure is necessary in order to ensure uniform pressure and achieve contact of EasyLay UDL SA with the underlying substrate.
  • Apply all succeeding courses in like manner, as described in steps above.
  • Prime all metal collars, flashings, valleys, liner and drip edge with ASTM D41 Primer, Water-based Acrylic Primer, or Water-based Polymer-Modified Primer. All metal shall comply with applicable Building Codes.
  • All protrusions shall be initially sealed with a trowel grade SBS modified bitumen asphalt adhesive/flashing cement and membrane. A subsequent application of similar self-adhesive membrane must be applied to the existing area and is to extend a minimum of 6” from the edge of the original penetration, where applicable.
  • Inspect all side laps, end laps, T-joints, eaves and rakes to verify they are securely sealed in place.
  • Carefully trim the excess material off the eaves and rakes.


Property Typical Value Reference Test
Tensile strength, MD and XMD        100 lbf/in ASTM D1970
Elongation, rubberized asphalt >150% ASTM D412 (Die C)
Adhesion to plywood at 40°F 4 lb/ft    ASTM D903
Adhesion to plywood at 75°F        20 lb/ft ASTM D903
Flexibility temperature -20°F ASTM D1970
Tear resistance 30 lbf ASTM D1970
Slip resistance Pass ASTM D1970
Nail sealability Pass ASTM D1970
Waterproof integrity of lap seams Pass ASTM D1970
Compound stability 240°F ASTM D1970
Moisture vapor permeability 0.1 U.S. Perm or Less ASTM E96

Product Data

Width 36 in (0.9144 m)
Length 72 ft (21.94 m)
Thickness 40 mil (nominal)
Gross Coverage 216 sq ft
Weight 50 lb (nominal)
Rolls per pallet 25


Tarco offers a 30 Year Limited Material Warranty.

Note: All statements, information and data, given herein are believed to be accurate and reliable but are presented without guaranty, warranty or responsibility of any kind, expressed or implied, except as may be indicated otherwise in this literature.

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