What is Tile Roof Underlayment?

tile roof underlayment

Gentle sounds of rain have the potential to calm a weary soul and let a tired person relax after a long day of work. Your sense of calm and peace can quickly turn to panic when you begin to hear the telltale drip of water in your home.

You can prevent a roof leak with the right tile roof underlayment. A tile roof ensures a longstanding, durable roof over your home. But the tile only works as well as the layer under it. 

A tile roof underlayment can protect your roof and, ultimately, your home from moisture damage. By the time you’ve finished reading this article, you will understand the value of a tile roof underlayment. 

What is Tile Roof Underlayment?

Tile roof underlayment protects the roof from moisture. It is a protective layer of material that goes between the actual roof, made of OSB or plywood, and the layer of roofing tiles. This water-resistant barrier protects the roof from long-term water damage if a tile cracks or breaks. 

If your tiles sustain damage, you still need to call a roofing expert for roof repairs. The roofing underlayment will protect the roof while you wait for the roofer to replace or repair your tile. 

Types Of Underlayment

There are two common types of roof underlayment. You can have either synthetic underlayment or asphalt felt underlayment installed. 

Asphalt Felt Underlayment

Engineers designed asphalt felt underlayment to shed water should it sneak under the roof tiles. The manufacturers soak a base material in asphalt to create this underlayment. The underlayment improves the roof’s durability, but it tears more easily than other underlayment types. 

When the felt underlayment tears, it exposes the roof to moisture and, thus, moisture damage. Such damage will cause mold, mildew, water damage, and leaks. If you leave it long enough, the moisture can cause structural damage as well as mold, which can cause long-term health problems for the building’s occupants. 

You can purchase felt underlayment in two different weights: 30-pound felt and 15-pound felt. A 30-pound felt stands up better to the elements because it is significantly heavier than a 15-pound felt. However, it is also heavier and more difficult for roofers to work with because of its weight.

Synthetic Underlayment

Synthetic underlayment offers more protection than asphalt underlayment. It also costs more than asphalt underlayment. 

Engineers manufacture synthetic underlayment from durable polymers. As a result, it is lighter and more resistant to moisture and fungus than asphalt underlayment.

It is also a stronger material than felt underlayment. Thus, it can withstand the trauma of hail and debris that comes with severe storms. Asphalt underlayment will tear with such battering while a synthetic underlayment stands firm. 

Furthermore, because it is durable, roofers have an easier time installing it without damaging it. As a result, the roof is protected better from moisture that could ultimately lead to leaks. 

So while synthetic underlayment will cost you more, it offers more protection and security. You can rest easier at night with a synthetic underlayment, knowing you have a secure, dry roof. 

Things to Consider

The type of roofing underlayment you choose depends on several factors. Weather, cost, and roof slop all play a part in determining what type of roofing underlayment you should purchase. 


If you live in a climate with moderate or mild weather, asphalt underlayment will provide adequate protection between your roof deck and roof tiles. If you live in a more extreme area, though, where you regularly receive hail, extreme heat, intense winds, ice, or snow, then you should purchase a synthetic underlayment. 

The synthetic underlayment will cost you more, but it will provide better protection against the weather events that threaten the longevity of your roof tiles and roof in general.


As stated before, asphalt will cost less than synthetic underlayment. If you have a tight budget, you may have no choice but to purchase asphalt felt tiles. 

However, if you can purchase a more expensive synthetic underlayment, you will ultimately save money in the end. Yes, you will pay more upfront. But you will also provide long-term protection and thus save money down the road. 


A roofing contractor will best know which type of underlayment works best for your slope. Some slopes tolerate asphalt or synthetic better than others, depending on the amount of overlap needed. 

Benefits of Underlayment

A tile underlayment is essential when you have a tile roof. Yes, the tile offers excellent protection for your roof, but without an underlayment in place, you’re running a serious risk. Here are the major benefits of underlayment: 

  • Temporary protection when storms take place
  • Water-resistant layer under your tile
  • Protection from vapor
  • Protection from decking resins

It’s important to note that while underlayment is water resistant, it is not waterproof. This means it does not self-seal, and water can come through any holes a nail creates in the underlayment. 


The tiles on your roof never wear out completely. The material under them, though, will wear out in as little as eight years and as long as twenty years. If you’ve never replaced the underlayment on your roof, have a roofing contractor inspect your roof to determine the condition of your underlayment. 

You may have a few more years left on it, or you could have a potential disaster on your hands if you don’t replace it. You won’t know until you call in an expert. 

Protect Your Roof With Underlayment

Protect your tile roof and home with a tile roof underlayment. This water-resistant layer will keep unwanted moisture from your home and ultimately keep your home’s occupants safer and healthier. 

Are you looking for a roofing expert? If so, contact us. Our experienced staff is ready to help you with all your roofing needs. 

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    By Big Time Roof Team | Oct Mon, 2022| Uncategorized