The Comprehensive Guide to Spray Foam Roofing

For a durable and high-performing roofing material for your residential or commercial property, spray polyurethane foam (SPF), commonly known as spray foam roofing, is an excellent choice. With its superior insulation and waterproofing properties, it’s no wonder most experienced and reliable contractors prefer this roofing material for their projects.

If you plan to install spray foam roofing for any of your properties, you should arm yourself with the proper information.

What is spray foam roofing?

Spray foam roofing is a system that involves spraying a liquid mixture of isocyanate and polyol onto a roof surface. This mixture expands into a foam, which creates a protective layer across the roof to rejuvenate and minimize future roof repairs.

It consists of two main types: closed-cell and open-cell foam.

Closed-cell foam has a dense structure, which gives it superior insulation and water resistance properties. This density makes it particularly effective for roofing applications where robust insulation and moisture protection are crucial. It creates a solid, impermeable layer that enhances thermal efficiency and structural integrity​.

Open-cell foam, on the other hand, has a lighter, more flexible composition with cells that are not entirely enclosed. This type of foam provides less insulation and water resistance than closed-cell foam.

Although spray foam roofing is not the most widely recognized roofing material, it has existed and been used since the early 1960s across industrial, commercial, and residential sectors.

This versatile roofing system can last over 50 years with proper installation and maintenance.

Benefits of Spray Foam Roofing

Why use spray foam roofing for your property? Here are some key features of spray foam roofing:

Insulation

One of the notable features of spray foam roofing is its excellent insulation capabilities. The foam provides a high R-value, which allows it to offer significant resistance to heat transfer. This helps maintain indoor temperatures and lower utility bills​.

Waterproofing

It also plays a huge role in waterproofing surfaces. The seamless application of spray foam ensures that there are no joints or seams through which water can seep. This makes it highly effective in preventing leaks and water damage, especially when repairing a flat roof where water pooling can be a concern​.

Durability

Spray foam roofs are renowned for their exceptional longevity, often surpassing other materials in terms of improving roof longevity over the long run. One key factor contributing to this durability is the foam’s ability to expand and contract with temperature fluctuations without cracking. This flexibility ensures the roof remains intact and effective over many years.

Lightweight

Weighing as little as a quarter of a pound per square foot, spray foam roofing places minimal stress on the structure of a building. This makes it suitable for many different kinds of buildings, including older structures that may not support heavier roofing materials.

Environmental Impact

Spray foam roofing is considered environmentally friendly. It helps in reducing energy consumption and is often made from recycled materials. Plus, it does not emit harmful fumes​​.

Installation Process for Spray Foam Roofing

Installing spray foam roofing involves several critical steps to ensure optimal performance and longevity. Each step must be meticulously executed to achieve the best results.

Surface Preparation

Before applying spray foam, the roof surface must be thoroughly cleaned and free of contaminants. This preparation is crucial because any impurities on the surface can impede the foam’s ability to adhere properly.

Proper adhesion is essential for creating a durable, seamless layer that provides effective insulation and waterproofing. That’s why contractors often use high-pressure air or mechanical cleaning to ensure the surface is pristine before application​.

Application Conditions

The weather plays a central role in the installation process. Spray foam must be applied under specific conditions, typically requiring temperatures above 50 degrees Fahrenheit. The roof surface must be dry. If not, the moisture or ice can prevent the foam from adhering and curing correctly. Ideal application conditions ensure the foam expands and bonds properly, forming a solid and uniform layer. Contractors often monitor weather forecasts and schedule installations during optimal weather windows to avoid complications​​.

Application Steps

Once the surface is ready, spray foam roofing application follows the process:

Mixing and Spraying: The process begins by mixing the two main components of spray polyurethane foam—polyol resin and isocyanate—and spraying the mixture onto the roof using specialized equipment.

Expansion and Hardening: Upon application, it expands within seconds to many times its original volume. This expansion then fills in the gaps and creates a seamless layer over the roof’s surface. This process also allows the foam to conform to surface irregularities, making it suitable for roofs with complex shapes and multiple penetrations.

Layering: Contractors usually apply multiple layers of foam to achieve the desired thickness and insulation properties. Each layer must undergo curing before applying the next to ensure a strong bond and uniform coverage. This layering technique also helps increase the insulation value and structural integrity of the roof.

Top Coating: A protective top coating is added after the foam layers have been applied and cured. This coating protects the foam from UV radiation, weathering, and mechanical damage. It also enhances the roof’s durability and extends its lifespan. The top coat is typically made of silicone, acrylic, or polyurethane and can be re-applied periodically as part of regular maintenance​.

Suitability for Roof Types

Spray foam roofing is a versatile solution suitable for various roof types, each with specific preparation requirements to ensure optimal application and performance.

Metal Roofs: Spray foam roofing is well-suited for metal roofs. Before application, any rusted areas may require a rust-inhibiting primer to prevent further oxidation.

TPO (Thermoplastic Olefin) Roofs: For TPO roofs, a cover board must be installed over the existing membrane before applying spray foam. This is necessary to ensure proper adhesion since TPO surfaces are typically smooth and can be slippery. The cover board provides a suitable surface for the foam to bond with, ensuring a durable and effective roofing system​.

EPDM (Ethylene Propylene Diene Monomer) Roofs: Spray foam can be applied to all three types of EPDM roofs: fully-adhered, mechanically-fastened, and ballasted. For fully-adhered EPDM roofs, the foam can be sprayed directly onto the surface if it is aged (more than five years old). Mechanically-fastened EPDM roofs require a cover board for proper adhesion, while ballasted roofs need the ballast removed before installation.

Built-Up Roofs: Spray foam can also be applied to built-up roofs, whether they have a gravel surface or are smooth. For gravel-surfaced built-up roofs, a wet-vac process may be used to remove the gravel and provide a smooth surface for the foam application​.

Cost of Spray Foam Roofing

The cost of spray foam roofing can vary depending on different factors, including roof size, location, and the condition of the existing roof.
On average, the cost ranges from $1.00 to $3.50 per square foot. The initial cost may be higher than some traditional roofing materials. But, long-term energy costs and maintenance savings often justify the investment​ ​.

Why Trenton Roofing is Your Best Choice for Spray Foam Roofing

Choosing the right contractor is crucial to successfully using a spray foam roof. Trenton Roofing stands out due to its expertise and commitment to customer satisfaction. With a track record of successful installations and satisfied clients, Trenton Roofing ensures that your spray foam roofing project is completed to the highest standards.

Contact Trenton Roofing today for a free consultation and see how spray foam roofing can benefit your property.