Should My Roof Valley Be Open or Closed?

This topic will make good reading especially if you are building a house, or replacing your roof. If you ask a cowboy contractor should my roof valleys be open or closed, they could just recommend what’s easiest for them. However, at Valiant Exteriors we have another take. We prefer to explain the pros and cons as we do here, so the customer can make the informed decision best for them.

Should My Roof Valleys Be Open or Closed – It Depends

There are two main types of roof valleys common in Calgary:

1… Open valleys use V- or W-shaped channels in the length, which is the option we generally recommend. In this instance, the shingles overhang the edges of the channel by a safe margin, but not completely.

2… Closed roof valleys on the other hand use shingles to flow across the valley, so the roof material doubles as a channel. Although they may also use under layment beneath this in a ‘belts and braces’ arrangement.

How Will I Know Whether Open or Closed is Best for Me?

There are two levels of decision-making involved in deciding whether your roof valleys should be open or closed. The first relates to aesthetic factors, while the second criteria covers practical points.

Aesthetic Considerations Favour Closed Roof Channels

There is little doubt free flowing, closed channels are prettier to the eye. The roof material flows seamlessly over, so they are hardly noticeable. The job is usually cheaper to do, and money-saving tempts in these times.

However, and here’s the potential catch, there is more water flowing down a closed gutter than most other parts of the roof surface. Moreover, the design is not as robust as a metal lining to an open gutter. Therefore there is a possibility your roof surface could fail at one of its most critical points, after you stopped checking it any more.

Practical Considerations Lead Us to Favour Open Channels

Not all roof types / designs favour open channels, or closed ones for that matter. Local building rules may place restrictions, as may also community design standards. Perhaps give Valiant Exteriors a call on (403)829-1661 to find out. Or post us an email if this suits you more.

Our advice is free and without any obligation. We offer one of the best money back guarantees in the business. We love what we do, and we believe we do it well. We would be delighted to be of service if your roof, eaves troughs, soffits or sidings require attention.

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