Home » Open vs closed-valley roofs: the role of roof plumbing in Melbourne

Open vs closed-valley roofs: the role of roof plumbing in Melbourne

Look at any roof with inside corners. In particular, focus on the area where the two sections of roof meet – notice how there’s a small gap left over that runs the length of the intersection?

As the intersection of two sections of your roof, this area is one of the biggest problem areas for roof leaks, as they create an avenue for rainwater to slip into your roof and start damaging your ceiling.

Don’t start panicking just yet – metal roofing experts are well aware of this issue, and have devised roof plumbing techniques to keep water out seeping in via these corners.

Namely, roof valleys!

These are an important – and often overlooked – part of your roof plumbing.

When it comes to roof plumbing in Melbourne, we’ve noticed that while gutters are cleaned and downspouts flushed pretty regularly, not many people pay much attention to their roof valleys.

We explain why this is a tremendous oversight, and how the right roof plumbing team can help.

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Our roof plumbers in Melbourne explain roof valleys

The goal of roof plumbing is to get rainwater off your roof, and in doing so, protect your home from water damage and leaks.

Essentially, roof valleys roof plumbing fixtures that are installed in these gaps.

Typically made of sheet metal, roof valleys protect your house by:

  1. Covering up these gaps
  2. Helping channel water into your gutters

And if you take a look around at the different roofs in your neighbourhood, you might notice that each one employs one of two different methods…

What is open-valley roofing?

Like the name suggests, open-valleys are defined by being, well, open – unlike closed valleys, the valleys on these roofs are exposed and uncovered by the roofing material.

Before you start worrying, let it be known that this doesn’t mean that you’re more vulnerable to leaks – when properly installed, open roof valleys should be sealed, waterproof and airtight.

The sheet metal used in the valley is backed by a waterproof underlayer – during the installation, it will also sandwiched between another waterproof layer, and then sealed with waterproof sealant.

Additionally, with open valleys, there will often be a degree of overhang, helping to further reduce the amount of water that gets in.

What is closed-valley roofing?

Essentially, closed-valley roofing turns your entire roof into the roof valley!

When installing a roof with closed valleys, your roofing expert begins with a waterproof under layer, sealed using waterproof adhesive.

Instead of installing a metal valley like in open-valley roofing however, closed valley roofing involves cutting your primary roofing material in such a way that both sections of roof align perfectly, seamlessly covering up the edges on your roof.

When properly installed by a qualified roof plumber, closed-valley roofing can be extremely effective at keeping water out – not to mention, it’s also way more aesthetically-pleasing!

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What type of valley should you use in your roofing project?

Just like many of the other decisions you’ll need to make regarding your roof, there are several decisions you’ll need to make when deciding on your roof plumbing plan – in particular, the type of valley used in your roofing project!

While each person has their own reasons for choosing one over the other, some of the things you’ll want to think about include…


Everyone has their own preferences for how their roof should look – however, one thing the vast majority of homeowners will agree to is that having your beautiful roof broken up by an obvious line of sheet metal isn’t a great look!

Since they fit together seamlessly, closed-valley roofs hide the valleys altogether, which may be more pleasing to the eye.

Of course, it you opt for metal roofing installation, this isn’t a concern, as your roof will also be metal.

Not to mention, COLORBOND metal roofing comes in a variety of colours and finishes, allowing you to choose roofing and valleys that seamlessly blend together.


Which one is more expensive – open or closed-valley?

If you ask us, the answer is open-valley, almost every time.

Choosing open-valley roofing requires extra material for the valleys. This can potentially increase the cost of your project – especially if there are a considerable amount of valleys in your roof.

Not to mention, roof installation (regardless of whether it’s metal or tile) requires cutting your roofing material anyway. Just take a look at any house with open-valley roofing – you’ll notice that the tiles or metal around that area are already cut at an angle.

If you opt for closed-valley, all your metal roofing expert has to do is adjust the measurements!

Durability and practicality

Open valleys may be susceptible to overflowing – this can be problematic around the areas where the valley meets the rest of your roof if they aren’t properly trimmed or sealed.

During especially heavy rains, this can result in roof leaks.

Closed valley roofs aren’t without their flaws either – unlike open valley roofs, they have a single point of failure. Namely, there’s only one waterproof layer sitting between rainwater and the inside of your roof.

Additionally, when poorly installed, closed valleys can also result in water getting trapped underneath your roofing, resulting in long-term water damage.

Need your valleys repaired? Call Watermaster Roofing for Masterful roof plumbing in Melbourne

Watermaster Roofing has almost 20 years of experience looking after all aspects of metal roofing – we offer a wide range of services, including roof plumbing in Melbourne.

And in all those years, we’ve noticed that it isn’t your gutters, but rather, your roof valleys that are the most common source of leaks and roof plumbing problems.

Whichever type of valley you select for your roofing project, it’s important that they’re properly looked after, lest you suffer a roof leak further down the line.

Don’t risk it with DIY – call Watermaster Roofing the moment you suspect something is wrong with your roof.

Whether it’s your valleys, gutters, or any other roof plumbing fixture, it’s important that you get them maintained and inspected regularly, and repaired when needed.

With a service area that covers all of Melbourne’s south-east, Watermaster Roofing is ready to answer the call.

Give us a ring today on 1300 576 075, or click here to contact us online.

2023-10-17T23:14:40+00:00 July 5th, 2019|Metal roofing, Roof Plumbing|

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