Tile roofs have long been desirable for homeowners throughout the American Sunbelt, and their popularity continues to grow. Offering outstanding performance and reliability while simultaneously enhancing a home’s aesthetics, a properly installed and maintained tile roof has demonstrated performance ranging from 50-75 years.

And for areas that experience high winds and hurricanes, modern adhesive technology has emerged as an ideal alternative to traditional mechanical fasteners like screws, nails, mortar sets, or wire-tie systems. Polyurethane foam adhesive products have been tested and proven to withstand severe weather events via strong bonds that help roofs achieve their superior longevity. Indeed, when properly installed by trained professionals, roofs utilizing adhesives can achieve some of the highest possible wind uplift ratings, making them highly advantageous for extreme weather conditions in the United States. 

For these reasons, roofing professionals should be knowledgeable about the different types of roof tile adhesive options and how they can deliver outstanding performance. In this article, we’ll explore the numerous advantages adhesives hold over mechanical fastening methods, the differences between single-component and two-component roof tile adhesive options, and why proper application training is important. 

An Ideal Alternative to Mechanical Fastening

The primary reason foam adhesives have gained traction in the marketplace is due to their inherent advantages over traditional mechanical fastening methods such as screws, nails, or wire-tie systems. 

First, consider that foam adhesives can eliminate the need to penetrate the roof deck with thousands of mechanical penetrations which can compromise the plywood and underlayment and cause leaks. Depending on the roof pitch, mean roof height, and municipality where the project is located, professionals can reduce and virtually eliminate the need to puncture the roof decks by using polyurethane foam adhesive instead. 

Elsewhere, the application of nails and screws requires the right amount of pressure, which can vary among installers. A too-loose insertion can contribute to potential performance issues later on, especially in hurricane zones or other high-wind environments. Meanwhile, a mechanical fastener that has been applied too forcefully can cause a roof tile to crack or break. 

Depending on the roof pitch and local building code requirements, roof tile adhesives do not require the installer to puncture the roof deck. Instead, the foam adhesive creates a strong bond between the deck and the tile, functionally eliminating many of the concerns associated with mechanical fasteners. This process can eliminate the variance between a too-tight or too-lose nail or screw insertion and the potential issues associated with each. 

Differentiating Between Single-Component and Two-Component Adhesives

Polyurethane roof tile adhesives are available in two distinct product categories.

Single-component adhesives combine all chemical and raw material components in a single container—upon dispensation, they are combined and the adhesive moisture-cures soon after application. In two-component adhesives, adhesion chemistry and other materials are kept separate (typically in an A-side/B-side). The chemical reaction begins once the two components are mixed together at the dispensation point within the application assembly nozzle. Both options can provide reliable, long-term performance. However, there are some differences between the two that may make one option more suitable for a given application than the other. 

For example, two-component polyurethane adhesives provide excellent levels of wind uplift performance, beyond what single-component options are typically able to provide. Dependent upon paddy size, tile profile, paddy placement, and gram weight, a properly installed two- component adhesive system can withstand a category 5 hurricane. Additionally, third-party lab testing protocols and adhesive manufacturers’ code approvals show higher allowable overturning moment testing data for two-component systems. These characteristics make two-component adhesives uniquely suited to applications in hurricane-prone regions like Florida, where hurricane resistance is a top priority for building and construction professionals.

Two-component options can also offer supplemental tile support, contributing to higher break strength and overall long-term durability. Two-component products further maintain higher seismic performance compared to wire-tie applications—this makes them ideal for western areas of the United States that experience more regular seismic activity.  

By comparison, single-component options can deliver good, long-term performance while simultaneously offering some ease-of-use advantages. Because these products are available in handheld cylinders, applicators are able to move around a roof area more freely than when handling two-component products. Single-component systems’ portability also lends itself to easier application around hips, ridges, cut pieces and trim tiles. 

In the early morning hours of the workday, single-component products offer further application advantages, as they are able to be applied to damp substrates. For example, morning dew won’t prevent timely application. Single-component adhesives also maintain high yields, allowing contractors to maximize the number of tiles that can be secured with a single tank of product.

Ultimately, the choice between single- and two-component products boils down to contractor preference and the needs of the specific application. Contractors armed with the right information on the benefits of each can more easily make an optimal choice for any job. 

The Importance of Certified Application

Getting the most from roof tile adhesives depends not just on the products themselves, but on proper training and installation. Building officials, inspectors and municipalities might require roofing contractors to have been trained in proper product use by the manufacturer. This is particularly true in, once again, areas prone to extreme weather like Florida. Code officials will want to ensure that construction projects completed with adhesive products are being performed by professionals who’ve been properly trained.

Additionally, a job performed by certified applicators will tend to be more effective and go more smoothly.  Adhesives are typically dispensed through convenient and reliable gun/hose assemblies, enabling the installer to spray adhesive and secure tiles quickly and efficiently; an experienced, well-trained crew can complete a typical roof tile job in half the time it takes when utilizing mechanical fasteners. Contractors interested in using roof tile adhesives should seek out manufacturers that provide product-specific training and certifications.

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Roof tile adhesives represent an optimal solution for tile roofs, and building industry professionals stand to seize their benefits by understanding the technology and investing in proper training. Products that have been formulated for the highest levels of performance and ease of use can contribute to more reliable and more durable roofs while enabling professionals to work more efficiently and boost their bottom line.