Interface Waterproofing & Flashing Detailing
We waterproof every junction, penetration, and interface — ensuring your cladding system stays watertight, compliant, and built to last.

The weak points in most cladding systems aren’t the panels — they’re the joints.

Cladding failures are rarely caused by the product itself. It’s the detailing around windows, balconies, parapets, and penetrations where leaks start.

We’ve seen projects with brand-new fire-rated panels… already leaking within months. Why? Poor flashing and no interface waterproofing.

At Atomic Projects, we treat interface detailing as a critical scope item — not a side note.

We plan, install, and test every waterproofing junction, return, and termination to ensure long-term protection behind the cladding.

1. Where Interface Waterproofing Is Critical

We provide detailed waterproofing and flashing at:

  • Window and door returns
  • Balcony junctions and slab edges
  • Parapet walls and capping
  • Soffits, sills, and slab penetrations
  • Services penetrations (A/C, lighting, balustrades)
  • Roof-to-wall interfaces and facade transitions

Whether it’s a new build, recladding, or remedial upgrade — these areas need to be fully sealed and detailed to manufacturer spec.

2. Products & Systems We Use

We use premium waterproofing products from leading suppliers.

Typical materials include:

  • Polyurethane or hybrid sealants (Bostik, Sika, Tremco)
  • Bituminous flashing tapes
  • Preformed EPDM or rubberised corner patches
  • Flexible flashing membranes (Pro Clima, Protecto Wrap, Ardex)
  • Primers and sealants for concrete, metal, and fibre cement substrates

Installed with full attention to:

  • Movement joints and expansion gaps
  • Compatible surface prep and bonding
  • Sequencing with sarking, battens, and flashings
  • UV and long-term exposure resistance (where applicable)

3. Installation Process

Our step-by-step interface detailing process:

  1. Identify all junctions and interfaces requiring flashing
  2. Prepare surfaces: clean, prime, check moisture levels
  3. Install sealant backer rods where required
  4. Apply flashing membrane or sealant in proper sequence
  5. Overlay sarking or cladding to ensure full coverage
  6. QA check before panel installation resumes

We often conduct a final photo hold-point for engineer or consultant review.

4. Compliance & QA

We align our interface waterproofing with:

  • NCC Volume 1, Section F (weatherproofing)
  • AS4654.2 – Waterproofing for external above-ground use
  • Manufacturer instructions for waterproofing compatibility
  • Fire engineer details and cladding system junction specs

Our QA includes:

  • Photo logs of every junction treated
  • Material batch and brand logging
  • ITP hold point checklists
  • Optional hose/bucket test at balcony slabs or sills

5. Deliverables

You’ll receive:

  • Annotated interface photo pack
  • List of waterproofing materials used and their locations
  • Sealant joint matrix (if required)
  • ITP checklist with sign-off
  • Ready-to-send records for your fire engineer or certifier

6. Why It Matters

✅ Prevents water ingress behind panels

✅ Supports long-term durability of cladding system

✅ Ensures compliance with NCC and AS4654.2

✅ Reduces risk of defect liability claims

✅ Protects insulation, structure, and internal finishes

Outcome:

We don’t just make it look waterproof — we prove it is.

Every junction is sealed, tested, and documented to last the lifetime of the system.

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If you’re ready to get started, we're ready to help.

Take the next step and let’s build something that lasts.

📞 Call Us: 0410 515 509

✉️ Email Us: hello@atomicprojects.com.au

— Ben Tran, General Manager, Atomic Projects

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