Eichler homes are a hallmark of mid-century modern design in the San Francisco Bay Area. Their clean lines, open floor plans, and connection to nature continue to be coveted by homeowners today. But what about the roof? Many Eichler homes were built with tar and gravel roofs, a technology that’s past its prime. At Armstrong Foam Roofing, we understand the importance of protecting your Eichler’s unique aesthetic while ensuring its longevity.
We would like to discuss the limitations of traditional tar and gravel roofs and explore the superior alternative – spray foam roofing, also known as Spray Polyurethane Foam (SPF) roofing systems.
Understanding Built-Up Roofing (BUR) Systems and Tar and Gravel Roofs
Built-up roofing (BUR), also known as tar and gravel, is a traditional flat roof system that has been around for decades. While it offers some level of protection, it falls short compared to modern roofing solutions like spray foam. Here’s a closer look at the components and limitations of BUR systems:
Layers of Asphalt and Ply Sheets
- Base Sheet: The foundation layer adhered directly to the roof deck. Traditionally made of organic felt, modern BUR systems often use fiberglass or polyester mats for improved strength and fire resistance.
- Asphalt Layers: Hot asphalt, typically derived from petroleum, acts as the glue that binds all the layers together. Multiple layers (usually 2-4) are applied hot and mopped onto the previous layer with a squeegee-like tool.
- Ply Sheets: These are reinforcing fabrics placed between the asphalt layers. Traditionally organic felt was used, but modern BUR systems often utilize fiberglass or polyester mats for increased strength and tear resistance.
The Limitations of Tar and Gravel Roofing
While the gravel topping provides some benefits, it also introduces significant drawbacks:
Weight Burden
The primary function of the gravel is to add weight to the roof. This is crucial for flat or low-slope roofs like those on Eichler homes. The weight helps the roof resist wind uplift, which can occur during strong winds or storms. However, the added weight can be a major concern for Eichler homes. Since they were built in an era with different building codes and materials, some Eichler roof structures may not have been designed to handle the long-term stress of a heavy gravel roof.
Heat Absorption
Gravel has a dark color and absorbs a significant amount of solar heat. This can contribute to higher indoor temperatures and increased cooling costs in the summer months.
Limited Protection
While the gravel offers some protection from UV rays and hail, it’s not perfect. Over time, the asphalt layers underneath the gravel can degrade due to sun exposure, leading to leaks and roof failure.
Maintenance Challenges
Walking on a gravel roof for maintenance or repairs can be difficult and can damage the underlying layers. Additionally, loose gravel can clog gutters and downspouts, requiring additional cleaning.
Beyond the Weight: The Asphalt Problem
Another significant limitation of BUR systems is the use of asphalt. Hot asphalt application releases harmful fumes and requires skilled professionals to ensure proper adhesion. Asphalt itself is susceptible to cracking and breaking down over time, especially under extreme temperature fluctuations. These cracks can then allow water to seep into the lower layers, leading to leaks and premature roof failure.
Ponding Water
Flat roofs are susceptible to water pooling, especially after heavy rains. Tar and gravel roofs, with their minimal slope, can exacerbate this issue. Over time, ponding water can lead to leaks, roof rot, and structural damage.
Limited Lifespan
Tar and gravel roofs typically last 10-15 years, requiring more frequent replacements compared to modern roofing options like foam roofing systems.
Introducing the Modern Solution: Spray Foam Roofing for Eichler Homes
Spray foam roofing or SPF roofing systems offer a superior alternative to tar and gravel for Eichler homes. This advanced roofing system uses lightweight, closed-cell polyurethane foam sprayed directly onto the roof deck. The foam cures into a seamless, monolithic barrier with exceptional benefits:
Durability and Longevity
SPF roofs boast a lifespan of 30-50 years or even a lifetime with proper maintenance, significantly exceeding tar and gravel. As a result, it also eliminates the need for costly roof tear-offs and waste which will end up in landfills.
Superior Insulation
Closed-cell foam offers exceptional thermal resistance, keeping your Eichler cooler in the summer and warmer in the winter, leading to substantial savings in heating and cooling costs. This is because foam roofing is the most energy-efficient material available – over 500% more efficient than conventional roofs like tar and gravel.
Lightweight
Spray foam is incredibly lightweight, putting minimal stress on your Eichler’s roof structure. Foam roofing systems weigh approximately 60 lbs per 100 square feet versus 600 lbs per 100 square feet for a typical built-up roofing system like tar and gravel. This is a significant advantage compared to the heavy burden of a tar and gravel roof.
Waterproofing
SPF creates a seamless, watertight barrier that eliminates the expanding and contracting and separating that allows water and microbes to seep in and damage your roof. The risk of ponding water and leaks will no longer be an issue as it is with tar and gravel roofing.
Reflective Surface
Many SPF systems come with a white, reflective topcoat, which reflects sunlight and reduces heat absorption, lowering cooling costs.
Low Maintenance
Spray foam roofs require minimal maintenance compared to tar and gravel, saving you time and money. Basically, all you need to do is recoat it approximately every 20 years to ensure it keeps performing like new.
Eichler Homes and Spray Foam Roofing: A Perfect Match
Eichler homes are architectural gems, but their iconic low-slope roofs can pose unique challenges when it comes to roofing materials. Traditional options like tar and gravel roofs, while familiar, come with drawbacks that can compromise the integrity and energy efficiency of these mid-century modern marvels. Thankfully, spray foam roofing offers the perfect solution to Eichler roofing challenges. Let’s explore why spray foam is the ideal choice to protect your Eichler home for years to come.
Preserves the Mid-Century Modern Aesthetic
Eichler homes are prized for their clean lines, uncluttered exteriors, and seamless connection to the outdoors. Replacing the roof with a bulky, dark gravel surface can disrupt this carefully crafted aesthetic.
Here’s where spray foam roofing shines:
- Variety of Finishes: Unlike the traditional black gravel, SPF systems offer a variety of finishes that complement the Eichler design. A popular choice is a white, elastomeric coating that reflects sunlight and mimics the clean lines of the home.
- Seamless Integration: Spray foam application creates a monolithic, seamless roof surface. This eliminates the cluttered look of gravel and exposed seams, maintaining the clean lines and minimalist aesthetic so characteristic of Eichler homes.
- Low-Profile Design: SPF roofs maintain the low-profile silhouette of Eichler homes. The lightweight nature of the foam allows for a thin yet highly effective roofing system, preserving the original architectural intent.
By choosing spray foam roofing, you can ensure superior protection for your Eichler home without sacrificing its iconic mid-century modern aesthetic. It’s the perfect blend of modern technology and timeless design.
Lightweight Advantage
Eichler homes were constructed during a specific era with building codes and materials of that time. While known for their innovative design, the roof structure of some Eichlers may not have been designed to handle the long-term weight burden of a traditional tar and gravel roof. Fortunately, the lightweight nature of spray foam roofing offers a significant advantage:
- Reduced Stress: Spray foam is incredibly lightweight. This translates to a dramatic reduction in weight placed on your Eichler’s roof structure. This lessened stress can significantly extend the lifespan of your roof and minimize the risk of structural damage.
- Peace of Mind: Many Eichler homeowners may have lingering concerns about the weight capacity of their roof. Upgrading to a lightweight spray foam system provides peace of mind, knowing your roof is protected without putting undue strain on the underlying structure.
- Retrofit Potential: The lightweight nature of spray foam also makes it an ideal choice for retrofitting existing Eichler roofs. In some cases, it may be possible to install spray foam directly over a structurally sound existing roof, eliminating the need for a complete tear-off and disposal of the old roofing materials. This can save on time, labor costs, and environmental impact.
By choosing spray foam roofing, you’re not just protecting your Eichler home from the elements; you’re also safeguarding its structural integrity for future generations.
Energy Efficiency
The San Francisco Bay Area is known for its mild climate, but keeping your Eichler home comfortable year-round can put a strain on your heating and cooling bills. Spray foam roofing’s exceptional insulation properties can significantly exceed traditional roofing materials. This translates to a well-insulated barrier that keeps your Eichler cooler in the summer and warmer in the winter. As a result, your Eichler home will have a more comfortable living environment and reduced reliance on your heating system. This means that you will also have a smaller carbon footprint and a positive impact on the planet. Investing in spray foam roofing is an investment in energy savings and environmental responsibility.
Investing in the Future of Your Eichler Home
Upgrading your Eichler’s roof from tar and gravel to spray foam is an investment in its longevity, energy efficiency, and curb appeal. At Armstrong Foam Roofing, we have extensive experience working with Eichler homes. For over 40 years, have installed more residential foam roofing than any other company in America!
What’s more, Armstrong Foam Roofing offers you some of the best, longest-lasting warranties available. Our thousands of satisfied customers in the Bay Area, including San Francisco, Oakland, Emeryville, San Rafael, Novato, Fremont, Dublin, Hayward, Livermore, and Palo Alto have never regretted having us replace their BUR roofing systems with our long-lasting SPF Roofing. Contact Armstrong Foam Roofing today to find out how spray foam roofing can improve the strength and durability of your Eichler home. Call us at (844) 796-1234 or fill out our online form to schedule a free consultation and estimate.