VFAST Series Stretchable Sill & Corner Flashing Tape is a smooth, highly conformable flashing tape developed for window sill pans, corners, curved openings and complex building-envelope penetrations.
Unlike pre-creped flashing products, VFAST uses a smooth, continuous and highly elastic waterproof carrier that can be stretched and formed directly around three-dimensional details. Its flexible construction allows a single piece of tape to follow sill corners, changes in direction and irregular transitions while maintaining a continuous water-shedding surface.
The high-performance butyl adhesive provides durable contact with common window profiles, wood-based panels, membranes and compatible mineral substrates. With an Sd value greater than 200 meters, VFAST also forms a highly vapor-resistant and airtight seal around critical opening details.
Designed for Complex Window Details
Conventional flat flashing tapes can require multiple cuts, folds and overlaps when used at sill corners. These additional joints increase installation time and may create potential weak points in the flashing layer.
VFAST is designed to stretch and conform around these details, helping installers create a more continuous connection with fewer separate pieces. Its smooth, non-creped surface provides a clean installation while the elastic carrier accommodates sill end dams, inside and outside corners, curved openings and changes in geometry.
Available Widths and Release Liner Options
VFAST is available in standard widths of 100 mm, 150 mm and 200 mm to suit different window-opening dimensions, sill depths and flashing requirements.
Custom split release liner configurations are available upon request. Split positions and individual liner widths can be adapted to different installation sequences, allowing the tape to be aligned with the window frame, sill surface and surrounding wall substrate before the full adhesive area is exposed.
Key Applications
- Window sill pans
- Window sill end dams and upturned corners
- Inside and outside window-opening corners
- Curved and arched window openings
- Door thresholds and complex flashing transitions
- Pipe and duct penetrations
- Irregular membrane-to-component connections
- Localized waterproof and vapor-tight detail sealing
Key Benefits
- Smooth, continuous and non-creped elastic surface
- Conforms around three-dimensional corners and irregular details
- Helps create a continuous water-shedding and vapor-resistant flashing layer
- Reduces cutting, folding and overlapping at complex window corners
- Highly elastic carrier supports controlled stretching and forming
- High-performance butyl adhesive provides durable contact
- Available in 100 mm, 150 mm and 200 mm standard widths
- Custom split release liner configurations available
Installation
Apply VFAST only to stable, clean, dry and frost-free substrates. Remove loose material, dust, oil and other contaminants before installation. A compatible primer may be required on porous, dusty or low-adhesion mineral substrates.
Position the tape before progressively removing the release liner. Form the material gradually around the detail and avoid concentrating excessive stretch within one small area.
Press the entire surface firmly using a hand roller, particularly around corners, edges and changes in direction. Ensure that the tape is fully supported and free from trapped air, uncontrolled folds or unbonded edges.
For best long-term performance, VFAST should be used as part of a complete Vantell window flashing and building-envelope moisture-management system.
