What Is Roofing Underlayment and Why is It Necessary?

Your roof is your first line of defense against the elements, which is why you should not take its structural integrity for granted. And roof underlayments can turn out to be the vital missing link in the structure that could ensure your home’s well-being, performance, and longevity.

What is roofing underlayment, and why is it important? This comprehensive guide has all you need to know.

What Is Roofing Underlayment?

It’s an additional layer of protection between the roof deck and the roofing material that guards against inclement weather. It is installed immediately below the asphalt shingles or any other roofing material. Its primary purpose is to supplement the protection provided by your roof and act as a second layer of defense against harsh weather conditions or usage-induced damage.

Despite serving a critical purpose, this vital element of every roof does not get its due attention. Lack of awareness has prevented wider adoption of roof underlayment.

It could make you wonder if you need one at all—there’s no simple answer to that question.

Although not mandated by any means, roofing underlayment brings about many benefits that homeowners should consider. It provides the following:

Safety Against Water Damage and Moisture Build-up

Even the best roofing material may suffer damage due to harsh weather conditions like lashing rains, high winds, or heavy snowfall. Other factors like long-term exposure, quality of roofing materials, the roof installation process, etc., can make your roof tiles susceptible to damage.

Any damage, whether big or small, can compromise the integrity of your roof. And once the external line of protection is breached, water and moisture, the sworn enemies of your roof, can make their way to your deck and the rest of your interiors. This will lead to rot, leaks, and the proliferation of mold and mildew.

In many cases, this spells extreme damage to your home and can lead to potentially fatal outcomes.

But when roof underlayments are in place, they act as a barrier to your deck so water or moisture cannot breach it. Added protection keeps your attic and the rest of your house safe from water and moisture-induced damage.

Insulation and Energy Efficiency

Certain types of roofing underlayment materials can provide added insulation to your home and guard against extreme weather conditions. Your house can remain warm or cool depending on the season and the prevailing climate in your area.

When your house can maintain mild indoor temperatures, it reduces the stress on your heating and cooling systems. And as you’re aware, a well-insulated home is significantly more energy efficient.

You consume less from the local utility grid, thus reducing your bills. Even for solar users, a well-insulated house is a boon because you don’t exhaust collected power regardless of the weather.

Protection and Longevity

If a storm blows away your roof tiles or your roofing material suffers partial damage for any reason, your roof deck becomes fully exposed, which may be catastrophic for your home. However, if you have a roof underlayment in place, it will shield the internal structure of your roof and house against damaging external factors until you can replace the roofing material.

That’s why the underlayment is vital if you’re doing regular roof repairs. By ensuring the structural integrity of your deck, roof underlayments boost its durability.

Of course, it is best to schedule a regular roof inspection to keep a close eye on the state of the structure. However, you can rest a bit easier knowing you have an extra layer of protection that can prevent frequent repairs or replacements.

As you can see, roof underlayment makes a strong case for itself. It not only keeps your home dry and comfortable all year round but also cuts down on long-term maintenance and repair costs.

Types of Roofing Underlayment to Consider

Much like roofing materials, there are many varieties of underlayments to choose from. Each underlayment material boasts unique properties and partners well with specific types of roofing materials.

Underlayment materials come in three major varieties:

Asphalt-saturated Felt

Also known as felt paper or roofing paper, it is a mixture of bitumen, cellulose, and polyester with asphalt. It’s a budget-friendly option that is the best choice for homes with slate or tile shingles. Although not waterproof, it is water-resistant and provides ample protection against elements like hailstones.

Asphalt-saturated felt works well with steeply slanted roofs where there is no probability of water accumulation.

It comes in two varieties: No. 15 and No. 30. The first is ideal for light-duty protection and is an excellent choice for garages. You should opt for No. 30 for the underlayment of the rest of your home.

Rubberized Asphalt

This is a combination of rubber polymers and asphalt. It’s the best choice for homeowners looking for waterproof roof underlayment. The material is self-sealing, self-healing, and self-adhering, so it is suitable for regions that experience heavy rainfall.

It is relatively expensive, but the protection you get is worth the investment. If you have a low-sloping roof and you’re looking for a premium underlayment material, rubberized asphalt is the best choice for you.

Synthetic Underlayment

Made from polyethylene or polypropylene polymers, synthetic underlayment is lightweight, durable, and provides excellent protection against water damage. It’s tear-resistant and can tolerate very high temperatures.

If you don’t want to blow your budget on rubberized asphalt, synthetic roof underlayment is your next best choice. Note that the material is not nearly as affordable as asphalt-saturated felt but significantly outshines it in performance.

Synthetic underlayment repels water, making it particularly helpful for roofs that are susceptible to mold.

What Kind of Roof Underlayment Should You Choose for Your Home?

The answer depends on several factors, including your current roofing material, budget, the climate of your region, and more.

AMECO Solar & Roofing, a prominent roofing company in California, can help you with roof installation services in California. You can utilize the roofing cost calculator to get an estimate of residential roofing installation in California.

Are you keen on installing underlayment for roofing? Contact us today to get started.