Out of sight, out of mind, we have all heard that phrase. However, for most homeowners, little to no thought is ever given about what lies underneath the shingle since it is only visible when the roof is torn off. Suffice to say, underlayment is actually one of many critical components responsible for the longevity and function of your home's roof. We always install roofing felt throughout the entire roof along with a second layer of ice and water guard for added protection to all chimney flashing, penetrations, and all valley areas where excess water can be a potential threat. This is a standard service for all of the roofs we build, at no extra cost, as we feel the extra protection against water leakage is absolutely necessary in building a quality reliable and robust roofing system.
What is Underlayment?
As recently as the 80's, underlayment was not considered a high priority on roofs. Some roofs did not even receive any underlayment at all. Thankfully, however, times have changed and due to many state and local and building codes, underlayment is now a required component when replacing a roof. Roofing underlayment is a layer of material that is installed on top of the roof decking and underneath the shingle. Traditionally, it is made of felt and saturated with asphalt so that it creates a bond with the asphalt shingles that are installed on top of it, thus producing an important sealing effect. Underlayment commonly comes in 15#(pound) and 30#(pound) types and is often referred by roofers as roofing felt.
Additionally, in today's day and age there have been many advancements in underlayment technology. Recently developed is a new synthetic underlayment based on synthetic polymers which add more high performance protection in specific roof applications or in conjunction with specific a particular type of shingle.
Since underlayment is such a critical component in a roofing system, many shingle manufacturers require a certain type of underlayment to accompany the shingle when installed in order to validate and maintain the manufacturer warranty. It is critical to communicate with your roofing contractor to determine which type of underlayment is best for your specific type of roofing system.
How Does Underlayment Work?
Understanding what underlayment does can provide you better insight of its importance to your specific application. To begin, we install underlayment immediately after a roof is torn off. The underlayment provides immediate coverage and protection to the vulnerable wood decking against water or moisture that may otherwise collect on the bare wooden decking. Additionally, a roof with a high pitch or very steep slope can benefit from synthetic underlayment in order to facilitate a better grip and provide added safety for our roofing crew when installing a new roof.
Synthetic types of underlayment or underlayment heavier than 15# are also often used to provide an ice and water barrier in vulnerable areas. This extra added layer provides additional protection against water pooling as a result of extreme temperature changes causing ice to dam and water to pool. In our experience, adding the extra ice and water barrier to all valleys, penetrations, and even under siding near chimneys is absolutely necessary in building a proper roofing system. Therefore, we do it on every roof we ever build, and that's why our stellar rating speaks for itself.
Underlayment also provides an extra seal around areas where the nail penetrates the wood thereby preventing a potential entry point for water. Furthermore, if water does find somehow its way underneath the shingle due to ice, snow, or wind driven rain, the underlayment provides an extra barrier of protection for your roof.
If you have any questions about underlayment and how it applies to your specific roof application, contact us we would love to help.