Why Weep Holes Matter in Roof Pointing - And Why Most Roofers Don't Install Them
If you’ve recently had your roof pointing done – or you’re getting quotes for the job – there’s a good chance nobody has mentioned weep holes. Most homeowners have never heard of them. Many roofing contractors don’t install them. And yet they play a genuinely important role in how long a pointing job lasts and how well your ridge line performs over time.
This post explains what weep holes are, why they matter and why at National Capital Roofing we install them as a standard part of every roof pointing job – when most contractors in Canberra simply don’t.
What are weep holes in roof pointing?
Weep holes are small, deliberate gaps left at intervals in the pointing compound along the ridge line during a roof pointing job. They’re typically spaced every few ridge caps and positioned at the base of the pointing where it meets the tile below.
Their purpose is simple: to allow any moisture that gets trapped beneath the ridge cap or within the bedding mortar to escape rather than sit there.
They look like small notches or gaps in the pointing – intentional, not accidental. To the untrained eye they might even look like a flaw. They’re not. They’re a sign that the job has been done properly.
Why does moisture get trapped under ridge caps?
Even on a well-pointed roof, moisture finds its way under ridge caps. This happens through:
Condensation – In Canberra’s climate, the temperature differential between a cold night and a warm morning causes condensation to form on roofs surfaces and within the ridge cap cavity. This moisture has to go somewhere.
Driving rain – In heavy or wind-driven rain, small amounts of water can work their way under ridge caps even when the pointing is intact. This is normal behaviour for a roof in exposed conditions.
Capillary action – Water moves through porous materials like mortar and concrete tiles through capillary action, drawing moisture into spaces that appear sealed from the outside.
In all of these cases, the moisture that gets in need to be able to get back out. On a roof without weep holes, it can’t – so it sits within the bedding mortar and beneath the ridge cap, where it does slow but consistent damage.
What happens when moisture can't escape?
When moisture is trapped beneath ridge capping with no way out, several things happen over time – and in Canberra’s freeze-thaw climate, they happen faster than they would in a warmer city.
Mortar deterioration – Bedding mortar that stays damp for extended periods softens and breaks down faster than mortar that dries out between rain events. This accelerates the very problem problem that pointing was supposed to fix, meaning the job needs to be redone sooner than it should.
Freeze-thaw damage – This is the big one for Canberra. When trapped moisture freezes overnight, it expands. That expansion puts pressure on the mortar, the pointing compound, and the ridge cap itself. Over repeated freeze-thaw cycles through a Canberra winter, this causes cracking from the inside out – damage that starts within the bedding and eventually works its way to the surface. It’s one of the reasons ridge capping on Canberra homes deteriorates fastes than in Sydney or Brisbane.
Efflorescence – Trapped moisture dissolves salts within the mortar and carries them to the surface as it eventually evaporates, leaving white staining along the ridge line. While mostly cosmetic, it’s a visible indicator that moisture is moving through the mortar rather than being managed properly.
Mould and biological growth – Persistent moisture within the ridge cap cavity creates conditions for mould, lichen and moss growth that further degrades the mortar and pointing compound over time.
All of these consequences are preventable. Weep holes give trapped moisture a clear exit point, keeping the bedding drier and extending the life of the repair significantly.
Why don't most roofers install them?
Honestly – because it takes more time and care, and most homeowners don’t know to ask for them.
Installing weep holes properly requires deliberate attention during the pointing stage. The spacing needs to be right, the positioning needs to allow drainage without compromising the waterproofing of the ridge cap, and the roofer needs to understand why they’re doing it rather than just applying the pointing compound as fast as possible.
For a contractor focused on volume and speed, weep holes are an easy thing to skip. The roof will look exactly the same without them. The homeowner won’t know the difference – at least not for a few years, when the pointing starts failing earlier than it should and the ridge caps need attention again sooner than expected.
It’s one of those details that separates a roof pointing job done properly from one done to a price.
How weep holes are installed correctly
When National Capital Roofing carries out roof pointing, weep holes are installed as a standard part of the process – not an add-on, not an optional extra.
After the new bedding mortar has been applied and the ridge caps are re-secured, pointing compound is applied along the ridge line in the normal way. At regular intervals – typically every second or third ridge cap – a small gap is left at the lower edge of the pointing, positioned to allow water to drain out from beneath the cap without creating a direct water entry point from above.
The positioning matters. A weep hole in the wrong place can allow water in rather than out. Done correctly, they sit at the lowest point of the ridge cap cavity so that gravity does the work – moisture drains down and out rather than sitting and accumulating.
The result is a ridge line that manages moisture actively rather than trapping it, which means the pointing lasts closer to its full design life and the overall repair performs significantly better through Canberra’s demanding seasonal cycle.
What to ask when getting roof pointing quotes
If you’re getting quotes for roof pointing, weep holes are worth raising directly. Ask each contractor whether they install them as part of their standard process.
If they say yes – good. Ask them to explain where and how they position them to confirm they understand the purpose rather than just agreeing to something they’ve heard of.
If they say no, or look uncertain – that tells you something about the standard of the job you’re likely to get.
It’s a small question that reveals a lot about how thorough a contractor’s approach actually is. The cheapest quote and the best quote are rarely the same thing on a pointing job, and weep holes are one of the clearest indicators of the difference.
The Bottom Line
Weep holes are a straightforward addition to a roof pointing job that meaningfully extend the life of the repair — particularly in Canberra’s climate where freeze-thaw cycles put trapped moisture under repeated pressure. They’re standard practice at National Capital Roofing because we’ve seen firsthand what happens to ridge capping when moisture has nowhere to go.
If your roof is due for pointing, or you’ve had a pointing job done in the last few years and want to know whether it was done to a proper standard, we’re happy to take a look and give you an honest assessment.
National Capital Roofing specialises in roof pointing across Canberra and the ACT. With over 25 years of experience and attention to the details that most contractors overlook, we deliver pointing jobs that last. Call us on 0407 212 491 or request a free quote online.
