How important is roofing underlayment?

roof underlayment

Your roof protects your home from the elements. Pretty basic stuff, right? Less obvious are the parts that go into the whole roof system. Not every home in Winnipeg needs the best roof underlayment available on the market and not every budget can afford it. A standard asphalt shingle installation does not require the same vapor protection that might be needed for a metal or slate roof, but a steep roof installation might be safer with the better walking surface provided by some synthetic underlayment.

The underlayment is a piece of material that is placed beneath the shingles on your roof that acts as a moisture barrier, preventing rain, snow, sleet, and other precipitation from being able to penetrate your roof and leak into your home. On this same note, it can also prevent any chemicals from the shingles themselves from leaking into your home as well. Your underlayment also provides a sound barrier between your shingles and your roof, allowing severe weather like heavy rains and hail to not sound deafening inside your home.

Roofing underlayment is a water-resistant or waterproof barrier material that is installed directly onto your roof deck. It is applied under all other roofing materials as an added layer of protection from severe weather. To decide which underlayment is the optimum choice for your project, you first have to understand the actual uses of underlayment and what they can and cannot do.

There are three main types of roofing underlayment:

  1. Asphalt-saturated felt
  2. Non-bitumen synthetic underlayment. This is also known as “synthetic underlayment.”
  3. Rubberized asphalt underlayment

Asphalt-saturated felt and synthetic underlayment are water-resistant. Rubberized asphalt underlayment is waterproof. Asphalt-saturated felt was the go-to roofing underlayment until about 15 years ago. That’s when synthetic products started gaining in popularity.

  • Commonly referred to as “felt paper” or “tar paper,” common roofing felt is made of varying blends of cellulose (natural plant fibers), polyester, bitumen or asphalt.
  • Basemat – the flexible base layer – is saturated with asphalt for water resistance.
  • Felt paper is applied across the entire roof deck. Depending on local weather, waterproof underlayment may be recommended.

Synthetic underlayment (technically non-bitumen synthetic underlayment) is the preferred underlayment of most roofing professionals today.

  • Synthetic underlayment basemat is saturated in asphalt. The addition of fiberglass gives synthetic products superior tear resistance and stability. RhinoRoof U20 is a highly engineered, mechanically attached, coated woven synthetic roofing underlayment for sloped roofs. RhinoRoof’s durable and high strength design along with its fiber grip walking surface provides a considerable improvement over asphalt saturated felt. The fiber grip textured walking surface can also be chalked just like felt. Unlike traditional asphalt saturated felts, RhinoRoof U20 can be used in extremely low temperatures without becoming stiff and difficult to unroll. It also does not dry out, crack, or leach oils in the heat like felt. RhinoRoof U20 is 100% synthetic and will not absorb water and wrinkle like felt. It lays flat and will remain 100% impervious to mold.
  • Synthetic underlayment is designed for application across the entire roof deck. It is sometimes used with waterproof products.

Rubberized asphalt is more expensive than other types pf roofing underlayment. Why? It contains higher percentages of asphalt and rubber polymers, making it waterproof.

  • Rubberized asphalt roofing underlayment often has a sticky back with a protective membrane that is removed prior to installation. This special backing creates the waterproof seal between the underlayment and a clean roof deck.
  • In severe winter regions, waterproof roofing underlayment at the eaves of a roof is helpful. The underlayment protects the edge of the roof deck from water damage.
  • Rubberized asphalt roofing underlayment should be added at valleys and around roof protrusions. These spots often get leaky first.

Why do you need roofing underlayment?

It’s a moisture barrier.

Roofing underlayment provides your roof with an extra layer of protection that shingles alone can’t match. Roofing underlayments perform many functions in a roof assembly, but first and foremost, they serve as the last line of defense between  homeowners and the damaging effects of water infiltration.

If you have further questions regarding which underlayment you should use for your roof replacement or installation, do not hesitate to speak to our team at All Weather Exteriors, We have proudly earned the A+ in BBB ratings meaning we have demonstrated a long and consistent record of completely- satisfied clients, use of quality materials, and  labor held to the highest degrees of workmanship.

For a free estimate, call All Weather Exteriors today at (204) 510-2959!

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