More often than not, when you need a complete roof replacement, one of the things that you will inevitably end up having to think about is the roof underlayment.
This choice also comes up during roof repair, although not quite as often.
The roof underlayment is definitely something that roof services will ask you about, because underlayment can make a huge difference in the durability and longevity of your roof.
Let’s talk about whether the traditional option of felt or synthetic material is better for your roof underlayment.
The first think you may need to understand is why you need an underlayment in the first place.
Why Use An Underlayment Under Your Roof?
Underlayment has many different uses that can be beneficial.
It is usually water resistant although not waterproof, meaning moisture in most cases cannot get down below to cause any structural issues.
If you are using asphalt shingles, your underlayment can protect them from any resins that were used in the decking. Underlayment is also useful for vapor protection.
Roofing Felt Underlayment
Roofing felt is basically 15# felt paper that is soaked in a mixture of asphalt and other water resistant compounds to produce the membrane.
Felt has been the underlayment material of choice for a long time and has become the traditional choice for most roof services.
As an added bonus, felt used for roofing also offers an excellent fire rating, which means that in conjunction with a fire-rated roof, you have a great chance of avoiding the spread of fire since both will be slow to burn.
Synthetic Underlayment Material
This is why synthetic underlayment is not used as often as felt, given that it costs more per sq ft than the traditional felt.
Fortunately, roof services have released products at competitive pricing that do offer durability and benefits.
As prices go down, more people will begin to use synthetic underlayment because it is very lightweight yet stands up to extreme and strong winds if any shingles are blown away.
It is also safer than felt for roofers to walk on while shingles are being installed.
Synthetic material is excellent for use under metal roofing and is also both water and vapor resistant.
Now You Can Make A Good Choice!
The best course of action is to seek the advice of roof services who are better able to give advice on your unique situation!