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Strait-Flex® Arch-Flex


Arch-Flex is designed for compound arches and double curve applications, including arched windows and doors, ceilings, soffits, staircases, barrel vaults, groin cathedrals; even taping around circular ducts.

Application(s): Drywall

Tear strips allow for straight-to-curve transitions in tight radiuses where conventional tapes show dents, paint chipping, shrinking and cracking problems. Apply with all-purpose joint-compound.

  • Arched windows and doors, tight radius curves, and free-form curves
  • Curved walls, ceilings, soffits, staircases, barrel vaults, and groin cathedral ceilings
  • Installs using standard compounds. No special tools or fasteners needed
  • Taping around circular air ducts
  • Produces smooth, professional-looking curves. Tear strips allow for easy straight-to-curve transitions.
  • Resists dents, paint chipping, shrinkage, and common cracking problems



  • Fold Arch-Flex in half at center crease. To ensure Arch-Flex lays flat on wall, fold less than desired angle for inside corners. For outside corners, fold more than desired angle.
  • Remove the tear strip by folding along perforation and pulling. For straight-to-curve transitions, remove the tear strip by folding along perforation and only for the curved area. Leave tear strip intact for the non-curved areas.
  • With a 4”or 5” taping knife, apply a smooth, liberal coat of all-purpose compound to corner.
  • Press Arch-Flex firmly into compound to form a uniform curve.
  • Wipe down tight and smooth with a 4”or 5” taping knife. Let dry completely.
  • Apply a fill coat of compound feathering the compound beyond the previous coat. Fill coat can be applied immediately after applying Arch-Flex. Lightweight compound used in this step makes sanding much easier. Let dry completely.
  • Apply finish coat. Let dry completely.
  • Sand lightly: 100-150 grit sandpaper (with finish coat of all-purpose compound) or 120-200 grit sandpaper (with finish coat of lightweight compound). Arch-Flex will not fuzz-up like other paper-faced arched products.

Code Approvals & Performance Standards


All stored materials shall be kept dry. Materials shall be stacked off the ground, supported on a level platform, and protected from weather and moisture.

Product Submittal Sheets

Click the below Product Code to view Submittal/Tech Datasheet.

Product Code Description
AF-50, AF-100 Strait-Flex Arch-Flex

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