Windows, Sills & Seals: Getting Flashing Tape Right on Site

Flashing tape might seem like a small detail but it plays a critical role in protecting buildings from moisture and air leakage.
In Episode 3 of The Masons Podcast, Michelle and Masons Technical Manager Arthur Whitfield break down what flashing tapes actually do, where they’re required under the New Zealand Building Code, and how correct installation protects framing from water damage.

This episode covers practical, real-world guidance for builders, designers, and specifiers working with wall underlays, flexible air barriers, and rigid air barrier systems.

In this episode we cover:

• Why flashing tapes are required around windows and joinery openings

• Waterproofing vs air control — what flashing tape actually does

• When you can (and can’t) mix flashing tape types on site

• Compatibility with flexible and rigid air barrier systems

• Common installation mistakes that reduce performance

• The importance of pressure-activated adhesives

• Why you shouldn’t stretch standard flashing tapes

• Nail and screw sealability testing — and why it matters at sills

• Product update: 40 Below now requires only ONE layer on the sill

• Temperature installation ranges for modern flashing tapes

• UV exposure and durability compared with wall underlays

• CodeMark certification and what it means for compliance

• Best-practice tips for installers

If you work in NZ construction, building envelope design, weathertightness, or façade detailing, this episode is packed with practical insight.