Complex Rooflines & Box-Gutter Remediation

What this service includes

Service Overview

Parapets and internal/box-gutters carry big catchments inside the building line — so when something’s wrong, water goes where it shouldn’t. Trevor treats these roofs like a system: catchments, falls, outlets, overflow paths, flashings and materials all working together. Calm, practical, and thorough — with fixes detailed to current NCC expectations and Victorian practice.

What You Can Expect

• System diagnosis — trace catchments, identify high points, and map primary vs overflow routes.
• Box-gutter redesign — set geometry/freeboard; add sumps, rainheads or scuppers as dedicated overflow.
• Flashings & penetrations — correct upstands/turn-ups and back-flashings at parapets and skylights.
• Materials & compatibility — fasteners, trays and gutters selected for coastal corrosivity and no galvanic clash.
• Staged construction — temporary drainage and weather protection during works to keep interiors safe.

In short: we stop guessing, prove the flow paths, and rebuild the system so storms have a safe, compliant way out — not through your ceiling.

Where This Service Fits Best

Common on heritage/commercial-style parapets and modern additions in:

• Mornington
• Mount Eliza
• Red Hill
• Flinders
• Balnarring
• Sorrento

Niche cross-overs we handle

• Roofing & coastal exteriors — re-sheeting, claddings and flashings to suit the new drainage scheme.
  See: Roofing & Coastal Exteriors
• Coastal corrosion & materials — marine-grade fixings and compatible metals for long life.
  See: Coastal Corrosion & Materials Upgrades
• Leak & draft diagnostics — blower-door/thermal imaging to confirm paths before you spend.
  See: Leak & Draft Diagnostics

FAQs

1. What actually fails on box-gutter roofs?
   Undersized soles/freeboard, no defined overflow, poor flashings at parapets or skylights, or incompatible materials.

2. Do I need a full reroof?
   Not always. Many chronic leaks resolve with box-gutter remediation and correct overflow devices (sump/rainhead/scupper).

3. What does “overflow provision” mean?
   A dedicated path that discharges to atmosphere if the primary outlet blocks (e.g., a rainhead or a side-overflow sump).

4. Can you make skylights leak-proof?
   We integrate trays and back-flashings into the roof drainage design — so aesthetics never override watertightness.

5. Will this meet current code?
   Yes — we align with NCC 2022 Housing Provisions for gutters/downpipes and Victorian practice for box-gutters.

6. What about extreme rain events?
   Systems are sized to code intent with overflow routes that dump water safely outside, rather than into the building.

7. How do coastal conditions change the design?
   Material selection and fastener compatibility are critical; we specify to the site’s corrosivity and avoid galvanic mismatches.

8. How long do these remediation projects take?
   Typically 1–3 weeks once access and materials are set; complex parapets or multiple stages can extend timelines.

See also (authorities & guides)

• VBA — Practice Note RP-02: Box-gutters (overflow devices & discharge)
• NCC 2022 — Part 7.4 Gutters & downpipes (selection, installation, overflow)
• NCC 2022 — Part 7.2 Sheet roofing (flashings, penetrations, water discharge)
• Master Plumbers/VBA — Roof drainage performance & overflow (slides)

Ready to Start?

If you’re dealing with chronic leaks or a parapet that never seems to cope in a storm, Trevor and the TimberTegrity team can help. We’ll trace the flows, design the right outlets and overflows, and rebuild the weak points — no pressure, just clear, builder-practical advice.
Contact us