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Composite Decking Expansion & Contraction: Miters, Butt Joints & Breaker Boards Explained - The Deckheads Podcast

Jun 18, 2026 · 40 min · Ep 291

Are your mitered deck joints opening up after installation? You're not alone — it's one of the #1 callback reasons for deck builders. In this episode of The Deckheads Podcast we break down everything you need to know about managing joints in composite and PVC decking.

🔧 WHAT WE COVER:

  • Why composite and PVC decking expands and contracts more than you'd expect
  • Mitered joints vs. butt joints — which to use and when
  • The "day 1 vs. day 100" rule for choosing your jointing method
  • When miters are acceptable (hint: keep it under 12 feet)
  • How to use breaker boards to define "rooms" and hide expansion
  • Fascia corners — why you should avoid mitering fascia, and what to do instead
  • Gap Cap: a new product that solves fascia corner and picture-frame joints
  • Why you must follow manufacturer gapping instructions to keep your warranty
  • How to protect yourself when a homeowner insists on a risky installation

🇨🇦 GAP CAP IN CANADA: We're the official Canadian distributor for Gap Cap. Canadian stock is landing soon — we'll be able to ship anywhere in the country. Builders and dealers: reach out about wholesale pricing.

🪵 BRANDS DISCUSSED: Deckorators Voyage • Eva-Last Apex Plus • Clubhouse PVC • Azek • Trex • Fiberon • Venture Decking

🛠️ PRODUCTS MENTIONED: Gap Cap • Axxent End Cut Paint • Marksman Pro X1 • Camo Fasteners

Whether you're a pro builder or a serious DIYer, understanding how your decking moves with temperature is the difference between a deck that looks great on day one and one that still looks great years later.

🛒 Shop composite and PVC decking: www.tuds.ca 📲 Follow us: Instagram: theultimatedeckshop Facebook: The Ultimate Deck Shop

#CompositeDeck #DeckBuilding #PVCDecking #DeckInstallation #DeckTips #MiteredJoints #BreakerBoard #GapCap #Azek #Trex #DeckPodcast

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