When it comes to roofing, valleys are the straight lines formed when two different planes of the roof meet. Valleys are usually found where gable dormer roofs meet the main roof. The opposing surfaces of the roof planes is where the water runs off and is channeled towards the edge of the roof. This vital area really handles a lot of the water run-off. So, if the valley’s flashing is not properly installed, the water will leak into the home, which can cause damage to its internal structure.
There are actually two common methods of flashing for completing the valley areas of the roof: open valleys and closed valleys. What exactly are the differences between these two valley systems?
Open Valley Roofs
An open valley is where a layer of lining is added into the valley. A pre-bent sheet of metal is then fastened on top of this. The material used is manufactured from any metal that resists the effects of natural weather conditions. Afterwards, the shingles are installed, and some overlap the metal. This is done on purpose to expose the valley, hence its namesake.
The reason behind exposing the valley is so roofing repairs can easily be made when certain issues suddenly occur. An open valley system sheds ice and water quickly and can reduce granule loss on your shingles so your overall roofing system will last much longer. This valley system can also have a positive visual impact on your home with the right materials installed.
Closed Valley Roofs
Compared to open valley systems, a closed valley system is faster and easier to install. Once the base roofing underlayment is installed, the shingles are installed over the areas where the two roofs intersect, as opposed to leaving them exposed in open valley systems. The valley will be completely covered with the shingles by the time the roofing installation is finished. This is a cost-effective way to install flashing on roofing and is often done for the aesthetic qualities it can give. They don’t require extra materials layered on it as well. The shingles themselves serve as the valley lining that handles the water run-off.
No matter what kind of roof installation you need for your home, our team at Crown Roofing can get the job done with your best interests in mind. Call us today at (604) 370-6288 for more information. You can also contact us online by filling out our convenient request form. We serve in New Westminster, Surrey and neighbouring areas.