The Ultimate Guide to Spray Foam Roofing

You’ve got questions about Spray Foam roofs, such as:

 

  • What is spray polyurethane foam (SPF) roofing?
  • What are the advantages of a spray polyurethane foam roof?
  • What problems do spray polyurethane foam roofs have?
  • How much does a spray foam roof cost?
  • How does a spray foam roof get installed?
  • How does spray polyurethane foam perform against other roofing systems?
  • How long will a spray foam roof last?
  • How is a spray foam roof repaired or maintained?
  • Common questions to ask a commercial roofing contractor
  • What are some case studies about spray polyurethane foam roofs?

West Roofing Systems has the answers

 

In this guide, West Roofing Systems answers all of the most common questions building owners have about spray polyurethane foam (SPF) roofing.

The goal is simple. To give you all the answers you need to know to make the best decision for your business. Let’s begin!

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What Do You Want to Learn About First?

[click on any chapter below to go directly to it]

Chapter 1: What is Spray Polyurethane Foam Roofing?

Chapter 2: What Are the Advantages of an SPF Roof?

Chapter 3: What Problems Do SPF Roofs Have?

Chapter 4: How Much Does a Spray Polyurethane Foam Roof Cost?

Chapter 5: How Does an SPF Roof Get Installed?

Chapter 6: Spray Polyurethane Foam vs Built-Up Roofing

Chapter 7: Spray Polyurethane Foam vs Single-Ply Membrane

Chapter 8: Spray Polyurethane Foam vs Silicone Restoration Membrane

Chapter 9: How Long Will an SPF Roof Last?

Chapter 10: How Is a Spray Foam Roof Repaired or Maintained?

Chapter 11: Common Questions to Ask a Commercial Roofing Contractor

Chapter 12: Case Studies on SPF Roofs

Chapter 1: What is Spray Polyurethane Foam Roofing?

Spray Polyurethane Foam Roofing, or spray foam roofing, is a material that’s sprayed as a liquid so it can expand into a foam, creating a solid layer across an existing roof.

The usual application of spray foam is to repair and re-invigorate an existing roof by removing the saturated areas, replacing with like materials, and then spraying foam over top of the entire roof.

While SPF roofing is not the most known type of roofing material, the technology has been around since the early 1960s for industrial, commercial, and residential facilities. An SPF roofing system can be used in any climate, and when correctly installed and maintained, can last over 50 years.

Spray Polyurethane Foam (SPF) for roofing applications is manufactured on the jobsite by mixing two highly reactive chemicals.

The chemicals, A (polyol/resin) & B (isocyanate) , are pumped from separate containers through heated, high-pressure hoses to an internal mixing spray gun.

Many changes have occurred in the equipment and chemistry of polyurethane roofing in the last fifty years, resulting in today’s dependable roof applications.

Spraying Foam on roof of school with windscreen

 

Chapter 2: What Are the Advantages of a Spray Polyurethane Foam Roof?

So, you’ve come to a point where you need a new roof and are looking for options. Perhaps fixing leak after leak is becoming a rather annoying part of your job description.

Should you continue the short-term gain of fixing leaks, or should you invest into a more cost-effective, long-term option?

The first question I have for you is, how long until you retire?

The second question I have for you is, how open are you to change?

Change is hard. I just got a notice from my credit card company that my cable bill went up $50. Looking into it, after two years of loyal service (and ending my new customer pricing), I was now handed a higher monthly bill.

Most people would be lazy and just accept paying more. I wanted to open my horizons to change, introducing me to the world of online streaming services.

Upon research, I can cut the cord and bring a monthly cable and internet bill down from $202/mo down to $120/mo!

I just had to be open for change and give it a chance.

The same can be said for spray polyurethane foam roofing systems. Most people wouldn’t be open to change and just install the same roofing system they’ve had on for years.

But for anyone to change, the clear benefits need to be there.

Let’s get rolling…

Here Are the 7 Primary Advantages of a Spray Polyurethane Foam Roofing System

 

  1. High R-value
  2. Renewable
  3. Quickly installed
  4. Self-flashing
  5. Seamless
  6. Easy to maintain
  7. Proven since the 1960s

 

1. Spray foam roofs have a high R-value

 
Spray polyurethane foam has the highest R-value of any commonly used roof insulation. Here are the average R-values for some common roof materials

  • Spray Polyurethane Foam: 6.6 per inch
  • Metal: 0.00 per inch
  • BUR Gravel: 0.34 per inch
  • BUR Smooth: 0.24 per inch
  • XPS Insulation: 5.0 per inch
  • EPS Insulation: 3.85 per inch
  • Polyiso: 5.5 per inch

R value is the capacity of an insulating material to resist heat flow. The higher the R-value, the greater the insulating power.

The higher the R value, the less heat or cool air that will pass through. Higher R value = less HVAC use = lower energy costs

Total payback of your new roof usually occurs in less than ten years through savings in heating and cooling costs.

2. Spray foam roofs are renewable

 
One of the benefits of a polyurethane roof is its ability to be re-coated.

A properly installed and maintained spray polyurethane foam roof should not require re-coating for 10 to 20 years. The best way to determine when a spray foam roof needs to be re-coated is to measure the remaining coating thickness on the roof and recoat before the coating is too thin to provide U.V. protection.

The first application of coating is usually applied at a thickness of 20-30 mils.

After 10 years, the coating could be reduced to a thickness of 7-10 mils, depending on the wear of the roof.

Many coating manufacturers offer extended warranties with each re-coat. This option, along with scheduled maintenance, allows a spray foam roof to be a truly renewable roof system.

3. Spray polyurethane foam roofs are quickly installed

 
Spray foam roofs are installed quicker than other roofing systems, due to:

  • Most SPF roofing projects involve little to no tear off
  • Spray foam roofs are spray-applied, meaning they can go around penetrations with ease
  • Spray foam roofs require less material and equipment than traditional roofing systems

One example would be roofing around a penetration. With spray foam being “spray-applied”, it would take about 2 minutes to roof around a penetration, as opposed to rubber roofing, which can take at least 30 minutes due to the custom cutting of materials.

4. Spray polyurethane foam roofs are self-flashing

 
Self-flashing refers to spray foams ability to conform to irregular shapes. Watch the video below which shows spray foam being sprayed around a curb:

In the video, it says it might take a conventional roofer 30 minutes to flash around a curb, spray foam can be applied in about two minutes.

Other roofing systems, like rubber, will need to be custom cut in order to be installed properly around a curb.

Self-flashing allows spray foam to be applied faster around all penetrations, including:

  • Parapet walls
  • Vents
  • Pipes
  • HVAC units
  • Skylights
  • Drains

5. Spray polyurethane foam is seamless

 
A big advantage spray polyurethane foam has over other roofing systems is that it’s seamless.

Being seamless, and therefore monolithic and watertight, avoids traditional single-ply membrane seams that tend to be the sources of leaks.

Seam separation of a rubber roof. An invitation for water penetration that will cause a roof leak.

How do leaks form on a rubber roof?

Seams start to separate over time and allow water to get inside. Also, they can allow some water to get in, it freezes, and when it thaws out, it breaks apart the seam even more.

Wind uplift is also an issue with seams. Wind will eventually get underneath a slightly separated seam, loosen and eventually allow an opportunity for water to enter the building.

With spray foam being seamless, there is no opportunity for wind to get underneath a spray foam roof.

6. Spray polyurethane foam roofs are easy to maintain

 
Perhaps a sharp tool has been dropped or the HVAC guy planted the HVAC panels in your roof like a javelin.

In order to fix these minor repairs, all you’ll need is a utility knife and some caulk.

Step 1: cut out the defective area

Step 2: dry the area out

Step 3: apply caulk and smooth

That’s it. Minor repairs can be done by in-house maintenance staff.

In fact, here at West Roofing Systems, we’ll take time at the end of the project to show you how easy it is to repair a small incision.

7. Spray polyurethane foam is proven to be beneficial

 
Since the early 1960s, spray polyurethane foam roofs have been installed and re-coated, strengthening the popular phrase, “A spray foam roof is the last roof you’ll ever have to install.”

Multiple roofs that have been installed decades ago are going on their 2nd or 3rd re-coat.

Spray foam: A cost-effective and versatile roofing solution

 
Polyurethane roofs are installed quickly, resulting in a lower labor cost and less interruption. When considering the many variables in a re-roofing project, the versatility of a polyurethane roof makes it a logical and cost-effective solution.

 

Chapter 3: What Problems Do Spray Polyurethane Foam Roofs Have?

West Roofing Systems has installed all types of roofing, and none of them are without problems. Our Maintenance and Repair Service (M.a.R.S.) team follows up with our customers to keep their roofing systems in tip top shape.

These are a few common problems we see with SPF Roofing and how you can solve them:

1. Weakness to UV Rays

The greatest weakness to spray polyurethane foam is its inability to resist ultraviolet rays of the sun.

Within 72 hours, uncoated spray foam will begin to deteriorate.

Under direct sunlight, spray foam will degrade at a rate of 1/16th inch per year.

Solution

To protect a spray foam roof from UV damage, various types of elastomeric membranes are installed.

Possible membranes are:

  • Silicones
  • Urethanes
  • Acrylics

These coatings are spray or roller applied (depending on the amount of wind) over the spray polyurethane foam, forming a seamless protective membrane.

In addition to UV protection, these coatings are engineered to provide waterproofing, impact resistance and improved fire ratings.

Here is a video showing a spray foam roof from start to finish, but if you play the video, it’s fast-forwarded to show foam being sprayed down, and a base coat of silicone (grey-colored) sprayed over top:

2. Limited Installation Window

SPF Roofing is a spray installation, this application technique means that the SPF needs to be installed in specific weather conditions. The best weather conditions are warm and dry with minimal wind.

This means that you are at the mercy of Mother Nature to get your roof repaired or installed.

Solution: Contact your contractor before your area’s roofing season, that way you can schedule your installation early, and you have plenty of time to reschedule if the weather changes.

3. Finding the Right Contractor

As foam roofing gains popularity with commercial property, you want to make sure you find a reputable contractor. Unlike traditional roofing, installing an SPF roof requires knowledge of the chemicals and application techniques. Installation requires a high degree of technical expertise and experience.

Solution: Check to see if your potential contractors are certified and take part in industry organizations. The Spray Polyurethane Foam Alliance (SPFA) has an ISO-17024 compliant certification program that has multiple levels, requires the contractor to pass an exam and meet the criteria for a certification. You can find a database of certified contractors online.

4. Overspray Potential

The spray application of SPF roofing means that the wind could carry to spray onto cars and other surfaces. While this does not pose a health concern, it is a concern for surrounding property.

Solution: There are multiple ways to prevent this from happening. Have a discussion with your contractor to ensure that they utilize industry best practices to prevent overspray. If it does happen, your contractor should cover cleanup costs.

5. Upfront Costs

For an average 20,000 sq. foot commercial roof, it will usually cost between $4.00 and $7.00 per square foot in materials and labor to install a typical SPF roofing system. Compared to other flat roofing systems, this upfront cost can be higher.

Solution: An SPF roof pays for itself quickly with energy savings and longevity of the roof. You can work with your contractor to calculate potential energy savings to make sure you installed the right thickness of SPF.

6. Maintenance

SPF roofing systems should be regularly inspected whether there is known damage or not–especially after severe weather events that could cause damage, such as hail storms, tornadoes, and hurricanes. Punctures and damage should be caught early to prevent leaking into the facility.

Solution: Most contractors have maintenance plans and warranties to keep your roofing system in decent shape. West Roofing System’s M.a.R.S. Program offers multiple packages to fit your needs.

7. Punctures

SPF does not have as high of resistance to punctures or damage. An SPF roof has a top layer of silicone; in the event of severe weather, there is a chance for the roof to suffer from a puncture. Usually, this kind of damage can be found with regular inspections before leaking occurs.

Solution: You can contact your contractor for a repair. The repair needs to be made with silicone because conventional roofing repair materials do not adhere to the silicone coating. It’s best to keep up your roof warranty so that it will be covered.

8. Expired Warranty

When you install a new roofing system, its best to purchase a warranty. Most manufacturer warranties require the contractor to perform repairs for the first few years after the install.

Solution: With SPF roofing, you can renew your warranty by restoring your roof with a new coat of silicone.

Spray foam: no roofing system is without problems

No roofing system is immune to needing repairs, that’s why it’s important to keep up your warranty and work with contractors that you trust. Spray Polyurethane Foam Roofing Systems are becoming the go-to roofing for commercial, industrial, and manufacturing facilities that are looking for a sustainable, economically efficient option.

At West Roofing Systems, our goal is to get you a long lasting, durable roof that will protect your facility. That includes working with our award-winning team to choose the best roofing systems to meet your needs.

 

Chapter 4: How Much Does a Spray Polyurethane Foam Roof Cost?

Our sales team is asked every day, “How much does a Spray Polyurethane Foam (SPF) roof cost?” and it’s not easy to give just one answer.

There are many factors that can affect the price of a commercial roof; from the weather to the location to the material choices.

Today we’ll review the average price of an SPF roof and break down factors that could change your price. Keep in mind that when you are looking to invest in a new roofing system, it’s a good idea to get a couple of quotes from different contractors.

For an average 20,000 sq. foot commercial roof, it will usually cost between $4.00 and $7.00 per square foot in materials and labor to install a typical SPF roofing system. This price range is for an SPF roof of average thickness and building structure.

To get the best roofing system for the right price, you will need to consider these key factors:

The Size of Your Roof

When a contractor is pricing a new roofing system, the economies of scale start around 20,000 sq feet; which means after 20,000 sq. feet you can start saving money per square foot of roof.

Other size factors that can impact your cost also include:

  • The logistics of moving equipment up to and across a large roof
  • Debris removal costs
  • Material transport costs – this cost can take up 2-3% of the total project costs

Thickness of Spray Foam

On average, it costs $1.65 – $2.25 per square foot for materials and labor on a typical SPF roofing system, which is a 1.5in layer of foam. Although there are reasons that a building will need a thicker layer, the most common reason is for energy efficiencies.

The thicker you make the foam layer, the high R-Value your roof will have. An R-value is the measure of insulation (resistance to heat flow) for material. All states or regions have that require that a roof system has a minimum amount of thermal resistance on commercial, industrial, and institutional buildings.

Basically: the higher the R-value, the more the material insulates.

You can work with your architect or contractor to compare the energy cost savings to the additional SPF costs to find where you can save money. Studies show that SPF Roofing has the most rapid return on investment from energy savings.

Condition of Existing Roof

The condition of your existing roof will be a crucial factor in the cost of your new SPF roof. There are three options when dealing with the existing roof:

Clean and Prepare Existing Roof (No Significant Alterations) – $0.10 – $0.75 Per Sq. Foot

When you have a solid roof that doesn’t require major modifications or corrections, the contractor will need to clean and prepare the roof, so the foam adheres properly.

There are four ways a contractor can prepare a roof for SPF installation:

  1. Air Pressure Cleaning
  2. Powerwash
  3. Dry Vac/Ballast Removal
  4. Wet Vac for dirt, gravel and dust removal

 

Recovery Board Fastened On Top Of The Existing Roof – $0.60 – $0.80 Per Sq. Foot

Recovery boards are commonly used to recover and improve the application surface. This process could be used to cover joints and to provide a separation layer between the existing and new roofing systems.

Stripping And Removal Of Roof – $1.00 – $2.00 Per Sq. Foot

There are two main reasons a contractor would need to strip and remove your existing roof.

  1. A building can’t have more than two roofing systems. This means if you currently have two roofs, your contractor will need to remove them before installing your new roof.
  2. If your roof is damaged, saturated or unstable, your contractor will need to strip the existing roof to install a new working roof.

Silicone Coating

When the SPF layer has been completed, it is then sealed with a layer of silicone and embedded granules. These layers protect the roof and foam from UV light, weather, and impact. The cost is between $1.75 and $2.30 per sq. foot in labor and materials to install.

There is a two-coat minimum of the silicone coating. You can increase the thickness of the silicone layer depending on the warranty you choose. For example, a 20-year warranty will need a thicker layer of silicone than a 10-year warranty.

Access to the Roof

Not all commercial roofs are flat; not all roofs can be walked on. Additional costs can occur when your contractor has limited access to the facility roof.

Height and distances of the roof can be multipliers for the cost of your SPF roof installation. Sloped roofs often require the contractors to use a man lift or rappelling gear for SPF installation. Contractors may need to rent conveyance equipment such as a crane or passenger hoist to move the crew and equipment.

When teams are working on secure locations, such as an airport, they often need to keep up their Secure Identification Display Area (SIDA) authorization. This includes background checks and fingerprinting, which is an added cost for the contractors.

Type of Warranty

When you install a new SPF roofing system, you will have a few warranty options. The three most common types of warranties include:

  1. Contractor’s Warranty – No expense or less than $1,000
  2. Manufacturer’s Product Warranty – Low cost and low coverage
  3. Manufacturer’s Full System Warranty – $0.08 – $0.15 per sq. foot

So, there you have it – our costs for spray polyurethane foam roofing systems.

When you include the SPF, silicone coating, size, and access to the facility, warranty, and maintenance, the average cost of an SPF roofing system is between $4.00 and $7.00 per square foot.

It’s important to remember that based on your roofing contractor, location, and building, these prices will vary.

 

Chapter 5: How Does a Spray Polyurethane Foam Roof Get Installed?

Before the installation can start, the existing roof (or substrate) needs to be prepared. Rather than stripping the existing roof, the contractor will most likely prepare the substrate by getting rid of all dirt, dust, and contaminants. This can be done with air pressure, vacuuming, or even just sweeping.

The first layer put down by the contractor is the polyurethane foam. This foam is created by combining two liquids (a polyol/resin and an isocyanate) as it’s sprayed onto the existing roof substrate.

As the liquid is sprayed onto the existing roof, it creates a foam that expands 20 times in size to form a solid, seamless foam surface. When the foam has expanded, this layer can be between 1 and 1.5 inches in thickness.

Since the polyurethane foam adheres to most common surfaces, it can be installed on any roof slope.

When the SPF layer has been completed, it is then coated with a layer(s) of elastomeric silicone or acrylic coating with embedded granules. This layer is generally between 20 and 30 mils (a mil is a thousandth of an inch — .001 inch.) in thickness. The coating protects the roof and SPF from UV light, weather, normal wear and provides the required fire ratings.

When the installation is complete, it will create a seamless, durable, moisture-resistant renewable foam roof covering.

A completed spray polyurethane foam roof

 

Chapter 6: Spray Polyurethane Foam vs Built-Up Roofing?

SPF Vs. Built-Up Roofing: Which Is Best For A Flat Roof?

When you think of a commercial roof, you may think of black tar being mopped on a flat roof. But nowadays you have more options to meet your pricing and performance needs.

What is the difference between “traditional” built-up roofing and Spray Polyurethane Foam Roofing?

Let’s dive into the differences between built-up and SPF roofing systems to give you all the information you need in choosing which roof is the best fit for your facility.

SPF Vs. Built-Up Roofing: The Basics

Built-Up Roofing

Built-Up Roofing Systems have been in use in the U.S. for over 100 years. These roof systems are commonly referred to as “tar and gravel” roofs. Built-up systems are installed by alternating layers of asphalt or tar and supporting fabrics directly onto the roof. You can choose the number of layers (or plies) that are installed. The final layer of a built-up roofing system consists of stone or gravel.

Spray Polyurethane Foam (SPF) Roofing

Spray Polyurethane Foam is a liquid that is sprayed on the existing roof and expands into a foam, creating a solid layer across an existing roof.

While SPF roofing is not the most known type of roofing material, the technology has been around since the early 1960s for industrial, commercial, and residential facilities.

SPF Vs. Built-Up Roofing: Cost

Built-Up Roofing

For an average commercial roof, it will usually cost between per $5.50 – $8.50 square foot in materials and labor to install a typical built-up roofing system. This price range can change depending on the materials you choose.

SPF Roofing

For an average 20,000 sq. foot commercial roof, it will usually cost between $4.00 and $7.00 per square foot in materials and labor to install a typical SPF roofing system. This price range is for an SPF roof of average thickness and building structure.

SPF Vs. Built-Up Roofing: Installation

Built-Up Roofing

The first layer can adhere directly to the roof substrate. If needed, a base sheet can be fastened to the roof to create a flat and safe workspace. A built-up roofing system is installed by alternating layers of bitumen and reinforced fabric. Property managers can choose three, four or five ply roofs to meet their needs and budgets.

The last layer is rock or stone, this layer protects the underlying layers from UV rays, extreme heat or cold, and wind damage. A layer of gravel can be added to be more aesthetically appealing.

SPF Roofing

Before the installation can start, the existing roof needs to be prepared. Rather than stripping the existing roof, the contractor will most likely prepare the substrate by getting rid of all dirt, dust, and contaminants.

The first layer put down by the contractor is the polyurethane foam. This foam is created by combining two liquids as it’s sprayed onto the existing roof substrate. As the liquid is sprayed onto the existing roof, it expands to form a solid foam surface.

When the SPF layer has been completed, it is then coated with a layer(s) of elastomeric silicone or acrylic coating with embedded granules.

SPF Vs. Built-Up Roofing: Advantages

Built-Up Roofing

If properly installed and maintained, a commercial built-up roof can last 40 years. There are a few other benefits of built-up roofing systems:

  • Seamless and Waterproof – The continuous solid surface does not require joints or seams, removing the most vulnerable area for leaking.
  • Reflects UV Rays – provides ultra-violet protection.
  • Low- maintenance – Minimal upkeep needed after installation.

SPF Roofing

When properly installed and maintained, a commercial SPF roof can last 50 years. There are quite a few other benefits of SPF roofing systems:

  • Energy Efficient – SPF delivers thermal, air, and moisture barriers to provide the highest R-value per inch.
  • Durable – The foam material can expand and contract with the building, decreasing the likelihood of cracks and splitting.
  • Seamless and Waterproof – The continuous solid surface does not require joints or seams, removing the most vulnerable area for leaking.
  • Environmentally Friendly – In most cases, there is minimal stripping of the original roof – eliminating the need for costly roof tear-offs and waste. The materials that are used for SPF roofing systems are also environmentally friendly: Zero Ozone Depleting Potential (ODP), Low in the Emission of Volatile Organic Compounds (VOCS), Free from Chlorofluorocarbons (CFCS), Ultra-Low Global Warming Potential (GWP).

SPF Vs. Built-Up Roofing: Disadvantages

Built-Up Roofing

Built-up roofing systems have been around for decades; their longevity can only be obtained if the roof is maintained properly. Here are other disadvantages of built-up roofing systems:

  • Time – Slower installation timeframe
  • Safety – Hazardous fumes and vapors when installing it
  • Weight – Adds extra weight to the building structure
  • Costs – Installation costs

SPF Roofing

While the advantages of an SPF roofing system outweigh the disadvantages, there are a few things you should keep in mind. Here are disadvantages of SPF roofing systems:

  • Hire the Right Professional – The contractor needs to be precise with the application and have a solid understanding of the chemicals they are using.
  • Limited Installation Window – Installation of an SPF roofing system cannot be performed during cold, windy, or rainy weather.
  • Overspray Potential – Since the SPF is installed by a spray application, there is a risk of the wind carrying overspray onto surrounding cars and other surfaces.
  • Maintenance – SPF roofing systems need to be inspected twice a year at least.

 

Chapter 7: Spray Polyurethane Foam vs Single-Ply Membrane

Single-Ply Membrane Vs Spray Polyurethane Foam: Which Is Best For Commercial Flat Roofs?

When we meet with future clients, they’re usually comparing several types of roofing systems. We are always asked: Which is better? Which is more affordable? Which is best for long lasting protection?

Let’s explore the differences between single-ply membrane and SPF roofing systems to give you all the information you need in choosing the best roof for your facility.

The Basics

Single-Ply Membrane Roofing

Single-Ply Membranes are sheets of rubber and other synthetics that can be chemically adhered to insulation or ballasted creating a layer of protection on your commercial facility.

There are two main types of single-ply membrane commercial roofing: Thermoplastic Polyolefin (TPO) and Ethylene Propylene Diene Terpolymer (EPDM). They differ in their chemical makeup, how they are installed and their energy efficiencies.

Spray Polyurethane Foam (SPF) Roofing

Spray Polyurethane Foam, more commonly referred to as SPF, is a material that’s sprayed and expands into a foam, creating a solid layer across an existing roof.

While SPF roofing is not the most known type of roofing material, the technology has been around since the early 1960s for industrial, commercial, and residential facilities.

Cost

Single-Ply Membrane Roofing

For an average 20,000 sq. foot commercial roof, it will usually cost between $3.50 to $7.50 per square foot for EPDM and $3.50 to $6.50 per square foot for TPO, including materials and labor warranty.

Spray Polyurethane Foam (SPF) Roofing

For an average 20,000 sq. foot commercial roof, it will usually cost between $4.00 and $7.00 per square foot in materials and labor to install a typical SPF roofing system.

This price range is for an SPF roof of average thickness and building structure.

Installation

Single-Ply Membrane Roofing

The beginning of the installation process is similar between TPO and EPDM single-ply membrane roofing systems.

After the existing substrate is prepared, either by cleaning or removing the existing roof, the insulation is installed. There are a few types of insulation options the facility manager/owner can choose from Polyisocyanurate (Polyiso), Expanded Polystyrene (EPS), Extruded Polystyrene (XPS)

After the existing substrate is prepared, either by cleaning or removing the existing roof, the insulation layers are installed and covered by a cover board. There are three ways to attach the membrane to the cover board: ballasted, with an adhesive or mechanically fastened.

The significant difference between TPO and EPDM comes when it is time to adhere the membrane seams together. TPO uses a hot-air gun to melt down the membrane at the seams and fuse them together. EPDM is joined together with a seam tape.

Spray Polyurethane Foam (SPF) Roofing

Before the installation can start, the existing roof needs to be prepared. Rather than stripping the existing roof, the contractor will most likely prepare the substrate by getting rid of all dirt, dust, and contaminants.

The first layer put down by the contractor is the polyurethane foam. This foam is created by combining two liquids as it’s sprayed onto the existing roof substrate. As the liquid is sprayed onto the existing roof, it expands to form a solid foam surface.

When the SPF layer has been completed, it is then coated with a layer(s) of elastomeric silicone or acrylic coating with embedded granules.

Advantages

Single-Ply Membrane Roofing

If properly installed and maintained, a commercial single-ply membrane roof can last 30 years. There are quite a few other benefits of single-ply membrane roofing systems:

  • Proven Track Record – EPDM roofing has been used for commercial flat roofing for over 60 years. This amount of time on the market has allowed various laboratory and field studies to be performed and tracked.
  • Customer Choice of Insulation – Since single-ply membrane roofing does not include the insulation factor, as a customer you have more options to choose from to insulate your facility’s roof.
  • Class A Fire-Rated – TPO membranes and EPDM can achieve Underwriters Laboratories (UL) Class A fire resistance listings by adding fire retardant chemicals during the manufacturing process.
  • Reflective or Retentive – TPO is generally white and highly reflective. On the other side of the spectrum, EPDM is often described as “Black Roofs,” due to the natural dark color of the membrane.

Spray Polyurethane Foam (SPF) Roofing

If properly installed and maintained, a commercial SPF roof can last 50 years. There are quite a few other benefits of SPF roofing systems:

  • Energy Efficient – SPF delivers thermal, air, and moisture barriers to provide the highest R-value per inch.
  • Durable – The foam material can expand and contract with the building, decreasing the likelihood of cracks and splitting.
  • Seamless and Waterproof – The continuous solid surface does not require joints or seams, removing the most vulnerable area for leaking.
  • Environmentally Friendly – In most cases, there is minimal stripping of the original roof – eliminating the need for costly roof tear-offs and waste.

Disadvantages

Single-Ply Membrane Roofing

While the advantages of a single-ply membrane roofing system outweigh the disadvantages, there are a few things you should keep in mind. Here are disadvantages of single-ply membrane roofing systems:

  • Durability – Single-ply membrane roofing does not have a hard top layer to protect the synthetic rubber from dropped tools, gravel or loose screws from being pushed into the rubber membrane.
  • Seams – Although these seams are sealed either mechanically or with melting adhesives, they are still areas that are more vulnerable to leaks than other roofing systems.
  • Roofing Accessories – Penetrations such as skylights or vents need special attention during installation.
  • UV Rays – UV rays that shine directly on the roof can degrade the adhesives quickly over time.

Spray Polyurethane Foam (SPF) Roofing

While the advantages of an SPF roofing system outweigh the disadvantages, there are a few things you should keep in mind. Here are disadvantages of SPF roofing systems:

  • Hire the Right Professional – The contractor needs to be precise with the application and have a solid understanding of the chemicals they are using.
  • Limited Installation Window – Installation of an SPF roofing system cannot be performed during cold, windy, or rainy weather.
  • Overspray Potential – Since the SPF is installed by a spray application, there is a risk of the wind carrying overspray onto surrounding cars and other surfaces.
  • Limited Colors – The silicone coating that is applied to the foam comes in two colors: white and gray.
  • Maintenance – SPF roofing systems need to be inspected twice a year at least.

As you can see, both Single-Ply Membrane and SPF Roofing Systems have their benefits and drawbacks. Choosing which one is best comes down to a customer-by-customer basis.

 

Chapter 8: Spray Polyurethane Foam vs Silicone Restoration Membrane

Which roofing option is better for your building?

The best answer will always come after a roof assessment. But other factors matter too, such as:

  • Which roofing option provides a better opportunity for energy savings?
  • Which roofing option provides waterproofing?
  • Which roofing option is more cost-effective?
  • Which roofing option is easier to maintain?
  • Overall, which roofing option is better?

 
Let’s get started…

SRM vs SPF – Which roofing option provides a better opportunity for energy savings?

SRM

One reason building owners transition from a rubber roof (TPO or EPDM) and choose a Silicone Restoration Membrane roofing option, do so because of the gray/white color of the coating.

With rubber being dark, it absorbs the sunlight’s rays and is always so dang hot! In an SRM roofing job this year, we noticed a temperature of 192 degree (F) on rubber, and 142 degree (F) on the SRM area ten feet over.

Using white silicone coating can decrease your building’s energy use by 15 to 35%.

SPF

Spray polyurethane foam provides the greatest R value of any roofing solution. R value is the capacity of an insulating material to resist heat flow, thus keeping the cool/heat from escaping your building.

Industry standards suggests that a spray foam roof can pay for itself with energy savings in 5-7 years.

That number can go up or down depending on your current roofs condition.

EDGE = SPF

SRM vs SPF – Which roofing option provides waterproofing?

SRM

A silicone restoration membrane is spray or rolled over an existing roofing system. It’s smooth and covers all seams and holes from a previous system. Therefore, since SRMs are monolithic (just on the top layer though), they are considered waterproof.

SPF

Spray polyurethane foam is sprayed as a monolithic layer over an existing system. SPF will also, cover all seams and holes from a previous roofing system. SPF is closed-cell and therefore impenetrable by water.

EDGE = SPF

SRM vs SPF – Which roofing option is more cost-effective?

SRM

An SRM involves less materials than a SPF. An SRM is also less labor intensive. The process of how an SRM roofing system gets done is:

  • Identify wet areas
  • Make repairs
  • Power wash entire roof
  • Reinforce seams
  • Lay down silicone

Overall, a ballpark price for an SRM roofing solution is $2-$3.50 per square foot.

SPF

A SPF involves all the steps the SRM does, except you might have to lay down cover board so the foam adheres properly. Then you need to add in the cost of the materials and processes to create and distribute the actual foam.

Overall, a ballpark price for a SPF roofing system is $4-$7 per square foot.

SRM vs SPF – Which roofing option is easier to maintain?

SRM

Maintenance on an SRM system is quite minimal. Since the SRM is restoring and strengthening the existing membrane, you may have penetrations that vibrate and pull apart, but it’s highly unlikely.

SPF

More maintenance issues can happen on a spray foam roof, such as:

  • HVAC contractors who aren’t careful (jabbing panels) can penetrate the foam
  • Other workers dropping screws and stepping on them, breaking the foams membrane
  • Animal damage can occur. Raccoons can dig holes, birds can peck at the foam.

 
Although more issues can happen on a spray foam roof, repairing these problems is very simple. It usually includes a knife, cleaning/drying, applying sealant and smoothing.

EDGE = SRM

Overall, which roofing option is better?

According to Greg “Barney” Haas, a 30+ year veteran in the roofing industry, Spray Polyurethane Foam is a better roofing option.

The #1 reason is that on an SRM, you’re relying on the underlying insulation. Also, the boards you have underneath the SRM are not monolithic, so if it’s not done correctly, you could be losing R value.

You’re getting more R value with spray foam because you have a 1.5”, pure monolithic, closed-cell and waterproof layer.

Silicone Restoration Membrane vs Spray Polyurethane Foam Roofing Systems

Chapter 9: How Long Will a Spray Polyurethane Foam Roof Last?

One of the first questions we get asked by property managers is, “How long will a spray foam roof last?”

The answer is that a spray foam roof will last indefinitely if you keep up with the maintenance and recoat schedule.

We have proof. One of the first spray foam roofs we ever did was at Playhouse Square in Cleveland, OH in 1972.

spray foam roof on playhouse square

Foam was sprayed over Playhouse Square’s State Theatre Auditorium Roof in Cleveland, OH 47 years ago and it’s still performing as it did year #1.

How Does Spray Foam Last Indefinitely?

So, when we install a spray foam roof, they can come in a 10, 15- or 20-year warranty.

For example, when you get a 10-year warranty, you’ll get 10 years’ worth of silicone coating overtop of the spray foam, usually 20 mils thick.

During years 1-10, we came out 2x/year to perform simple maintenance on the roof. This maintenance is recommended but not required to maintain the warranty terms. Tasks performed are:

  • Visual roof inspection
  • Cleaning of drain, strainers and gutters
  • Cut out any defective areas, make sure they are clean and dry
  • Apply caulk/sealant to defective areas and smooth out
  • Provide a roof inspection report

But on year 11, when the warranty has run out, the original 20 mils of silicone coating, you might be down to 9 or 10 mils, maybe even less. It depends on where the roof is located at, the harshness of the weather that has occurred and the amount of foot traffic.

On year 11, there’s no need for a roof tear off. All that needs done is to pressure wash the roof, provide simple repairs and install new coating.

You also have the option of choosing a new 10, 15- or 20-year warranty, whichever works best for you.

What Happens During the Spray Foam Re-coating Process?

Step 1: Pressure wash the roof

Step 2: Walk the roof and fix any mechanical damages, such as blisters, holes or areas of wet foam

Step 3: Apply the new coating

How Much Does a Re-coat cost?

The average recoat will cost about 1/3 to 1/2 of the original cost of installation in today’s dollars.

The cost can vary depending on distance from our locations and how much repair needs done before the re-coat. Performing preventative maintenance ensures your re-coat will be on the lower end of the re-coat price range.

 Sample Lifetime Cost of a Spray Foam Roof
 
TOTAL*150,800
Sq. Ft. = 20,000
YearWork PerformedCost
1Installation in Fall 2019 ($5/sq. ft)100,000
2Maintenance in Spring or Fall (0.03/sq. ft)600
3Maintenance in Spring or Fall (0.03/sq. ft)600
4Maintenance in Spring or Fall (0.03/sq. ft)600
5Maintenance in Spring or Fall (0.03/sq. ft)600
6Maintenance in Spring or Fall (0.03/sq. ft)600
7Maintenance in Spring or Fall (0.03/sq. ft)600
8Maintenance in Spring or Fall (0.03/sq. ft)600
9Maintenance in Spring or Fall (0.03/sq. ft)600
10Maintenance in Spring or Fall (0.03/sq. ft)600
11Recoat ($2/sq. ft.) in Spring40,000
12Maintenance in Spring or Fall (0.03/sq. ft)600
13Maintenance in Spring or Fall (0.03/sq. ft)600
14Maintenance in Spring or Fall (0.03/sq. ft)600
15Maintenance in Spring or Fall (0.03/sq. ft)600
16Maintenance in Spring or Fall (0.03/sq. ft)600
17Maintenance in Spring or Fall (0.03/sq. ft)600
18Maintenance in Spring or Fall (0.03/sq. ft)600
19Maintenance in Spring or Fall (0.03/sq. ft)600
20Maintenance in Spring or Fall (0.03/sq. ft)600

Spray Foam: the last roof you’ll ever have to put on

In short, a spray foam roof should be the last roof you ever have to put on. After initial installation, it’s basically a maintenance item that can always be under warranty.

Throw in the energy savings with having a spray foam roof and it instantly becomes a cost-effective option.

 

Chapter 10: How Is a Spray Foam Roof Repaired or Maintained?

With a spray foam roof, you can simply do a recoat, and/or add sealant to the visible damage and you’re good to go. The level of repair depends on frequency and depth.

Here is a chart from the SPFA on mechanical damage and repair recommendations:

chart-showing-recommended-repair-for-spray-foam-roofs

A spray polyurethane foam roof is maintained (usually twice a year) by a:

  • Visual roof inspection
  • Cleaning of drain, strainers and gutters
  • Cut out any defective areas, make sure they are clean and dry
  • Apply caulk/sealant to defective areas and smooth out
  • Provide a roof inspection report

After 10 years of routine maintenance, your original 20-30 mils of silicone will probably be reduced to 7-9 mils.

At this point, it’s time to restore your roof with silicone coating to get you back to the original millage of material.

Once that’s done, it’s back to 10 more years of simple maintenance listed above in the bullet points.

 

Chapter 11: Common Questions to Ask a Commercial Roofing Contractor

Can I re-roof or do I have to tear off my existing commercial roof?

If you only have one roof on your building that is in good shape, chance are you can save money by installing a new roof without removing the existing roof. Unfortunately, there are instances where a roof tear-off is required:  

  • Your facility already has two roofs: According to law, commercial buildings may not have more than two roofing layers. This is to prevent excess weight and stress on the structure of the building.
  • Your facility has an unsafe roof: If your roof is damaged, saturated or unstable, your contractor will need to strip the existing roof to install a new working roof.

How do I know if my business needs a new roof?

Our experts will perform a free roof assessment to determine the quality of your existing roof. Internal damage you may spot such as roof leaks or mold, are indicators that your commercial roof could be unstable and need replacing.    

When should I schedule my roof survey?

The earlier the better! As soon as warm weather comes, contractors are up on roofing starting projects. It’s best to contact a contractor in The later summer to schedule a survey as soon as the spring comes to your area. That way, they can start your project as soon as roofing season starts.    

How much will my new roof cost?

Each situation has its own unique challenges that cause the prices to fluctuate. We compete with all the viable and high performing commercial roofing systems. There are many factors that contribute to the price of your new commercial roof.   Some of these factors include:

  • The size of your roof
  • Condition of the existing roof
  • Roof access
  • Insulation choice
  • Membrane choice
  • Installation choice
  • Roof penetrations
  • Type of Warranty

How long can I expect my commercial roof system to last?

The longevity of your commercial is dependent on many factors, from weather conditions to roof type.    There are averages for common roof systems:

  • Spray Polyurethane Foam: 30 – 50 Years
  • Single-Ply Membrane TPO: 15 – 20 Years
  • Single-Ply Membrane EPDM: 20 – 25 Years
  • Metal: 30 – 45 Years
  • Built-Up: 10 – 15 Years

How long does it take to install a new commercial roof?

The time of the project is dependent on a variety of variables such as the type of roof, the size of the roof,  existing damage, weather, inspections, and permits. Each job is truley unique and could take form a few days to a few weeks. When you talk to a roofing expert for an assessment, they should be able to include a proposed timeline in the survey report.    

How do I know which type of roof is right for my business?

Our roofing experts will work with you to determine the best roofing system for your facility based on climate, energy costs, and facility needs.   There are many roofing options for your commercial facility:

How can I choose the right commercial roofing contractor?

Choosing the right commercial roofing contractor to trust can be daunting. There are databases with accredited companies such as the Better Business Bureau or the National Roofing Contractors Association. In addition, ask your contractor what kind of training they do with their crews and what certifications they hold with suppliers and industry organizations.  

At West Roofing Systems, our teams hold many certifications: PCP Certified Company, OSHA 500, 510, 7500 Certified Trainer, NRCA Certified in Fall Protection among others, in addition to belonging to industry organizations such as The Spray Polyurethane Foam Alliance and The National Roofing Contractors Association.  

Is there anything I need to do to maintain my commercial roof warranty?

When you install a new roof on your facility, you will have a variety of warranties to choose from. The coverage of your warranty depends on the type of warranty you purchase. The most common warranty options include Contractor’s Warranty, Manufacturer’s Warranty, and a Manufacturer’s Full System Warranty.   These warranties can cover a variety of roofing issues such as:

  • Roof leak repair
  • High winds
  • Hail damage coverage
  • Roof puncture coverage

Most roof warranties require or recommend regular roof inspections and maintenance. In addition to a proper maintenance program, Roof Restoration is a great way to renew your roof warranty.  

What should I do in the case of an emergency commercial roof leak?

If you find that your commercial roof is leaking, Your first priority is to protect what is in your facility first. This could mean moving furniture or covering equipment to protect from water damage. When your property inside the facility is protected, mark the leak area to show a professional later.   If your roofing contractor has an emergency contact number, this is the time to utilize their services. If they don’t have emergencies, contact them the next day during business hours.  

 

Chapter 12: Examples of spray foam roofs from the 70s, 80s and 90s

Since the early 1960s, spray polyurethane foam roofs have been installed and re-coated, strengthening the popular phrase “A spray foam roof is the last roof you’ll ever have to install”.

Multiple roofs that have been installed decades ago are going on their 2nd or 3rd recoat.

In fact, our first example, Brian Chavalia (now in sales and ownership of West Roofing Systems, Inc.), was the master sprayer on a job he did 27 years ago. Now he’s going back for a recoat. Check out the video on Central Village below:

Central Village Apartments in Amherst, Ohio

Initially Installed: 1992

Number of recoats: 2

Playhouse Square in Cleveland, Ohio

Initially installed: 1972

Number of recoats: 3

Sandusky Schools in Sandusky, Ohio

Initially installed: 1980

Number of recoats: 3

Are You Ready to Talk About Your Roof?

 

The goal of this page is to give you the complete guide on everything spray foam roofing-related.

We just wanted to help you by giving you all the information available in one area, in hopes that you can use this to make the best possible decision for your building.

At West Roofing Systems, we’ve been installing spray foam roofs for over 40 years and have helped thousands of buildings stay leak-free, while providing the best possible insulation (hello energy savings).

After installation, all you have to do is worry about the recoats every 10-15 years (which are about 1/2 to 1/3 of the original cost of installation) and you’ll have a roof that will maintain leak-free well past retirement.

In fact, the quote we always use is “a spray foam roof will be the last roofing system you ever have to install.”

Thank you reading our extensive article! If you’re interested in hearing from us, please click the button below and we’ll be happy to answer any and all of your questions within 48 hours.

 

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