When it comes to roofing, the details matter, and one of the critical aspects to consider is the valley system used. Roof valleys are the internal angles formed by the intersection of two sloping roof planes. They play a vital role in diverting rainwater off the roof. The two most common types of valley systems are open and closed valley roofing. This article will delve into the differences between these two, helping you understand which might be the right fit for your home.

Open Valley Roofing System

In an open valley roofing system, a strip of the roof deck is left exposed. This strip is usually covered with a layer of metal, such as copper or aluminum, which is visible and helps to divert the water down the roof. Open valley systems are appreciated for their durability, as the metal resists wear and tear, and the lack of overlapping shingles reduces the chance of debris getting trapped and causing water buildup.

However, open valley systems are typically more expensive due to the additional cost of the metal strip. Furthermore, the visible metal may not appeal to homeowners who prefer a seamless aesthetic for their roof.

Closed Valley Roofing System

A closed valley roofing system, on the other hand, does not expose any of the roof deck. Instead, roof shingles overlap from one plane of the roof to the other, creating a 'closed' valley. This method often matches better with the rest of the roof since the same shingles are used. Closed valleys are typically less expensive to install because they require fewer materials.

Nevertheless, closed valley systems might not be as efficient in water runoff as their open counterparts, especially if not installed correctly. They can also be more prone to leaks due to water potentially seeping through the overlapping shingles.

In conclusion, the choice between an open and closed valley system often depends on your budget, aesthetic preference, and specific requirements for water runoff. Always consult with a professional roofing contractor to determine the best option for your home.