What’s the Deal with Underlayments

It seems that the topic of underlayments can be confusing for most homeowners.  There are various options for most roofing systems.  The most commonly known  underlayments are peel and stick (ice and water) and synthetic.  There are different types of peel and stick depending on the roof system that is being used. 

There are multiple options for shingle underlayments.  At Three C’s Roofing, we primarily use synthetic underlayment for our shingle roofs.  While peel and stick has its merits and is necessary in critical areas of the roof, synthetic allows the structure to breathe better which is important in Florida’s humid climate.  For synthetic underlayment to be effective as a secondary water barrier, the roof should have a 4 pitch or higher. Proper installation of synthetic requires that it be installed at a half lap, this means that 50% of the roll is covered by another roll leaving only half of the roll exposed. This gives you two layers of protection which is code for synthetic in Florida. (Synthetic can also be used in metal roof applications though not recommended by Three C’s Roofing) 

The next option for shingle roofing is a 30 lb. felt underlayment.  This is the more traditional underlayment that more people may have heard of.  While felt is an effective underlayment, it is more labor intensive to install due to the rolls being significantly smaller than a roll of synthetic but being installed in the same manner with a half lap method.  For an average sized home, 6-7 rolls of synthetic would be sufficient whereas felt would be 18-20 rolls making the cost of materials and labor considerably higher.  

There are a couple of types of peel and stick, commonly called ice and water shield. All peel and stick underlayments are self-adhesive as the name implies.  They can be used as a single layer barrier to shingles, metal and tile roofs.  But there are different grades depending on the roofing system being used.  Shingle grade is typically a smaller roll with a mineral surface on the face of the roll.  This can be used to cover the total roof area or in critical areas such as valleys and walls when using synthetic. 

When installing tile or metal roofing, the rolls are larger and thicker with the face being covered in a cloth-like fiber to give it more resilience. This product is designed to perform in Florida’s hot temperatures and is commonly referred to high temp peel and stick.  

As you can see, there are many choices for underlayment and knowing which suites your needs best can be challenging.  The choice of underlayment generally depends on your environment and the roofing system being used.  It is our job here at Three C’s Roofing to help you make the best decision to fit your situation.   Call us today!