Polyguard

Poly Wall® Butyl Flash Window Flashing Tape

Poly Wall® Butyl Flash Window Flashing Tape

$65.49
  • SKU: POL BF4100
  • Availability: This product typically ships within 2 business days if ordered Monday to Friday by 2 PM EST
  • Shipping: Free Shipping
Availability: This product typically ships within 2 business days if ordered Monday to Friday by 2 PM EST
In Stock & Ready To Ship!
Current Stock:Only left:
Description

Polyguard BF20 Butyl Flash is a high-performance 20 mil self-adhering flashing tape used to seal straight window frames, door frames, and construction seams. Designed with a butyl-based waterproofing coating and laminated to a polyethylene film, BF20 provides excellent adhesion, flexibility, and weatherproof protection—even in cold temperatures down to 15°F. With a 120-day UV exposure rating and easy peel-and-stick application, BF20 is ideal for long-lasting, weather-resistant installations.

Features & Benefits

  • Cold Weather Application: Can be installed in temperatures as low as 15°F.
  • High Heat Performance: Handles service temperatures up to 240°F.
  • Self-Sealing: Seals around fasteners, nails, and staples for leak-resistant protection.
  • Excellent Adhesion: Adheres to common construction substrates without primer in many conditions.
  • Easy to Use: Comes in roll form with removable film release liner for clean, simple installation.
  • Moisture Defense: Acts as a vapor barrier and helps prevent mold and mildew.
  • UV Resistant: Up to 120 days of exposure.
  • Sizes: Available in 4", 6", 9", and 12" widths, each roll is 100 linear feet.

Technical Data

Property Result
Thickness 20 mils (±0.5)
Cold Temperature Flexibility Pass – No visible cracking at -25°F
Service Temperature Range 15°F to 240°F
Peel Adhesion on OSB 3.2 lbs/in
Peel Adhesion to Primed Steel (ASTM D1000) 6.1 lbs/in
Water Vapor Transmission (ASTM E96) 0.14 perms
Elongation (ASTM D412 Modified) M: 400% / T: 291%
Nail Sealability Pass (Before & After Thermal Cycling)
Self-Resistance to Peeling Pass

Recommended Applications

  • Window and door frame flashing
  • Sheathing joints
  • Transition detailing between building envelope components
  • Seams in weather-resistive barriers (WRBs)
  • Other above-grade waterproofing and air barrier detailing

Common Substrates:

  • Oriented Strand Board (OSB)
  • Plywood
  • Exterior Gypsum
  • Concrete
  • Rigid foam insulation
  • Polyguard membranes
  • Weather-resistant barriers (e.g., housewraps)

Application Details

  • Surface Prep: Ensure surfaces are dry, smooth, clean, and free of dust and debris. Avoid installation over uncured or incompatible sealants.
  • Primer: For difficult surfaces or cold-weather application, use Polybond Clear Liquid Adhesive or a compatible spray adhesive.

Installation Tips:

  • Always install on a back-dammed or positively sloped sill.
  • Apply sill flashing first, followed by jambs, then head flashing.
  • Do not cover the bottom window flange; leave for drainage.
  • Use a hand roller to ensure full contact and seal.
  • Protect exposed flashing within 120 days or cover with cladding.