Canberra storms dump a lot of water in a short time, and a box gutter has to get all of it off the roof before it backs up. If the sump’s blocked, the fall’s wrong or there’s no overflow, that water ends up in your ceiling. We inspect, test and fix box gutters on homes, townhouses, strata blocks and commercial buildings across Canberra, the ACT and Queanbeyan.
Call us 24/7: 03 8583 2640 or 0426 204 244
Find the cause, not just the drip
I’m Victor, and I run Holy Mess Repairs. With box gutters, the joint you can see dripping is rarely the whole story. It’s usually a mix: debris in the outlet, a channel that holds water, sealant doing a job that a proper fold or lap should be doing, and nowhere for overflow to go. Fix one and leave the others, and you’ll be back on the ladder after the next storm. So we work out the whole picture first.
When to suspect the box gutter
- A ceiling stain in the middle of a room or along an internal wall, under where two roofs meet
- Water coming in during short, heavy downpours or hail, then stopping
- Leaves, hail or debris sitting in the gutter or rainhead
- Water still sitting in the channel well after rain
- Joints or cappings smeared with silicone
- A newer home or townhouse that’s started leaking within a few years
Our process
- Inspect. Width, fall, outlets, sumps, joints, cappings and overflow.
- Water test. We clear it and run water through. If the leak still hides, we dye test the suspect sections.
- Show you. Photos and video of what’s failing.
- Options. Clean and reseal, replace a section, or a full new box gutter with new outlets and flashings.
- Fix and test. We flow test after the work so you can see it drain.
Reseal or replace?
Reseal when the steel is sound and it’s the sealant or one blocked outlet letting you down.
Replace when it’s rusting, too small for the roof area, flat or holding water, missing an overflow, or has been patched again and again.
We’ll tell you honestly which one you need, even when it’s the cheaper one.
Box gutters around Canberra
Townhouses and newer homes
A lot of Canberra’s newer townhouses and homes have low-pitch metal roofs, parapets and box gutters between dwellings. When these are built in a hurry, we see the same problems: cappings without enough fall, joints relying on silicone, and laps that are too short. They often show up within the first few years.
Strata and shared roofs
Where a box gutter runs over more than one unit, the first question is often who’s responsible. We give the owners corporation and strata manager a clear, photographed answer about where the water’s coming from and what it’ll take to fix.
Offices, schools and commercial buildings
Large flat or low-pitch roofs with plant on them send a lot of water and debris into a few box gutters. For facilities managers, we document the condition, the cause and the options, so you can approve the right scope.
After hail and big storms
Hail and leaves can block outlets in minutes. If your box gutter overflowed in a storm, we’ll check whether it was a one-off blockage or a gutter that can’t cope, and document what we find.
Watch: box gutter work
These clips are from our Melbourne jobs. The work is the same in Canberra.
Box gutter pricing
Typical box gutter prices (a rough guide only, plus GST):
- Small repair (one failed joint or a blocked sump cleared): about $350–$900
- Clean and reseal a full run, or reline it: about $1,500–$4,000
- Replacement: about $250–$750 per metre, and often more once new sumps, flashings, an overflow, height or plant on the roof are added
These numbers vary a lot from job to job. They’re based on what licensed roof plumbers and published cost guides in Melbourne, Canberra and around Australia charge in 2026. We always quote after we’ve inspected your gutter.
For a real reference point from one of our Melbourne commercial jobs (about 12 m of box gutter):
- Clean and reseal: $3,000 + GST
- Full replacement with new sumps and apron flashing: $10,500 + GST
Your job could be more or less. Height, plant on the roof, the outlets and whether an overflow is needed all affect the price. If the leak point isn’t obvious, a dye test first can keep the repair scope down.
Examples from our Melbourne jobs
We don’t have a Canberra box gutter case study written up yet, so here are recent jobs from Melbourne:
- Office roof (Dandenong, VIC): a sump almost fully blocked with sludge and a joint where the sealant had failed, with rust underneath. We gave the owner two options: reseal ($3,000 + GST) or replace ($10,500 + GST).
- Restaurant roof (Northcote, VIC): dye testing showed failed box gutter joints, ponding and a rusty sump among three leak zones.
- New build (Balwyn North, VIC): box gutter areas ponding and relying on silicone instead of proper folds, listed for the roof plumber to fix before final payment.
Warranty, in plain words
The warranty on a box gutter job follows the type of work and the materials used, and matches the material supplier’s warranty. A clean and reseal is a repair. It buys you time, and its warranty follows the sealant supplier’s. A new Colorbond or Zincalume box gutter carries the steel supplier’s warranty, and we register BlueScope warranties for you where they apply. Whatever you choose, we’ll tell you in writing what’s covered and for how long before you decide.
Why Holy Mess Repairs
- Licensed roof plumbers. Victorian roof plumbing licence 32176, recognised Australia-wide, including the ACT, under mutual recognition laws.
- Around 4.4 stars from 120+ Google reviews
- Photos and video of what we find and what we fix
- Honest options, from a reseal to a full replacement
- BlueScope warranties registered where they apply
- Open 24/7 across Canberra, the ACT and Queanbeyan
Canberra box gutter FAQs
How do I know if my box gutter is leaking?
Look for ceiling stains away from the outside walls, leaks in short heavy storms, and water sitting in the gutter after rain. We can confirm it with a water or dye test.
My townhouse is only a few years old. Why is the box gutter leaking?
On newer roofs we often find joints and cappings relying on silicone, short laps or not enough fall. Those problems tend to show up after a few seasons.
Can hail block a box gutter?
Yes. Hail and leaves can block an outlet quickly. Without a working overflow, the water backs up into the building.
Should I reseal or replace?
Reseal if the steel is sound and the problem is sealant or a blocked outlet. Replace if it’s rusting, too small, holding water or keeps failing.
What does box gutter work cost in Canberra?
As a rough guide: about $350–$900 + GST for a small repair, $1,500–$4,000 + GST to reseal or reline a full run, and $250–$750 + GST per metre to replace, often more with sumps, flashings and access. We quote on site. As a reference from one of our Melbourne commercial jobs, about 12 m of box gutter was $3,000 + GST to reseal, or $10,500 + GST to replace.
Do you work with strata managers?
Yes. We show where the water is coming from and give options the owners corporation can approve.
Do you cover Queanbeyan?
Yes. We cover Canberra, the ACT and Queanbeyan.
Can you find which section is leaking?
Yes. Water testing usually shows it. If not, a dye test pins it down.
Book a box gutter check
Find out why it’s failing and what it’ll really take to fix. Call us any time:
Holy Mess Repairs · Serving Canberra, the ACT, Queanbeyan and surrounding areas · Open 24/7
In Melbourne? See box gutter repairs in Melbourne. Need to find a hidden leak? See leak detection and dye testing in Canberra.