how durable is a spray foam roof

How Durable Is Spray Foam Roofing and How Long Will It Last?

Perhaps this is the first time you’ve considered a spray foam roofing system?

Like many others, you have lots of questions about it.

And we don’t blame you.

What good is a roofing system if it’s not durable to your conditions and climate?

And how long is it going to last?

In short, spray polyurethane foam has a compression strength of 50-60 PSI. That’s equivalent to the pegs that your refrigerator sits on. A sharp object (like heels) can crack a foam roof. If you’re expecting lots of foot traffic, a double broadcast of granules can be embedded into the top coat of coating for extra strength.

And a spray foam roof can last 50+ years.

A typical scenario is that someone gets a spray foam roof that comes with a 10, 15, or 20-year warranty. Once the warranty is over, the roof is cleaned and recoated, and then a new 10-20-year warranty begins.

West Roofing Systems has been a company since 1979 and there are roofs that our owners’ grandfathers sprayed 40 years ago. They still have the original foam on them. They are still going strong today because they have routine maintenance, and they did the recoats as soon as the warranty expired.

Here are some other questions related to durability that we’ll answer below:

  • What if your roof experiences lots of foot traffic?
  • What happens if the roof gets a crack or puncture?
  • Can the roof handle hailstorms?
  • Can animals damage a spray foam roof?
  • Can the roof withstand high heat and cold winters?
  • Explain how much it will cost for a spray foam roof to last 50 years?

What if your roof experiences lots of foot traffic?

Some companies need constant traffic on their roofs.

For example, a larger company may need constant maintenance on its HVAC units.

Would a spray foam roof hold up to that?

If you’re familiar with TPO, which uses walkways to handle excessive foot traffic, this is a little bit different.

A spray foam roofing system is installed in four different parts, they are:

  1. Spray polyurethane foam
  2. Basecoat of coating (needs to be installed within 72 hours of the foam installation)
  3. Topcoat of coating
  4. Embedded granules
spray foam, coating, granules

On a spray foam roof that needs a little extra protection, a double broadcast of granules can be embedded over dedicated areas, like this walkway below:

Walkway on a spray foam roof

What happens if the roof gets a crack or puncture?

Here’s something you may not know, every single roofing system available can get cracks and punctures.

Hail, flying debris, dropped tools. These are just some of the items that can damage a roofing system.

The difference between spray foam roofs and traditional roofing systems that use polyiso board for insulation is open and closed-cell properties.

Polyiso board has open-cell properties. This means if it’s exposed to water, water will travel throughout, saturating a large area.

Open-cell insulation, such as polyiso board.

Spray foam has closed-cell properties. This means if it’s exposed to water, water will sit in the crack and not move.

closed cell spray foam holds water in place

Closed-cell insulation, such as spray polyurethane foam.

If a spray foam roof gets a crack or puncture, a contractor will cut around the exposed foam, dry the area, and fill it with silicone sealants. Then smooth the area out.

It’s a simple repair.

The problem comes when these repairs are ignored for long periods of time. This is why it’s important to have routine maintenance with any roofing system you install.

Getting timely repairs extends the life of the roof and reduces future expenses.

NOTE: Routine maintenance on a roof is exactly like routine maintenance for your car. Would you rather pay $50 to replace the oil in your car twice per year? Or would you rather ignore the oil changes and pay $5000 for a new engine every few years?

Can a spray foam roof handle hailstorms?

hail damage on spray foam roof

Example of hail damage on a spray foam roof

Like any roofing system, if hail comes down with enough force, it can damage any roofing system. Because spray foam roofs are protected with coating and granules, it produces a rigid surface.

The rigid surface can still be damaged by hail, but the roof will not leak.

This is because spray foam has closed-cell properties.

If a hailstorm happens in your area, walk the roof the next morning and see if there are any cracks like the photo above.

If so, contact a spray foam contractor and they will repair them.

While no roofing system is 100% resistant against hail, spray foam has a few advantages:

  • SPF is usually installed 1.5 inches thick – thick enough to remain watertight from damage by large hail
  • Easier and cost-effective to repair than most other roofing systems
  • Closed-cell, meaning water cannot penetrate the foam even with hail damage

Can animals damage a spray foam roof?

There have been rumors of birds pecking a foam roof, or animals digging into the foam.

This used to be a problem many years ago. But with the addition of granules into the topcoat of coating, this is no longer an issue.

The granules create a rigid, tough, and undesirable surface for animals to peck or gnaw at.

Can a spray foam roof withstand high heat and cold winters?

Yes.

West Roofing Systems has installed spray foam roofs in the coldest climates including Canada, Minnesota, and upper Michigan.

We’ve also installed spray foam roofs in the warmest of climates including Florida, Alabama, Georgia, and even in Iraq!

In 2008, West Roofing Systems went over to Iraq to improve the living conditions for American soldiers. The barracks had leaking roofs, most barracks did not have much insulation value making the HVAC units inefficient, especially in 100+ F degree weather.

With spray foam being fluid-applied, it sealed all the leaks. And with spray foam offering the greatest R-value per inch of thickness, HVAC units were efficient, enabling a more comfortable environment.

How much will it cost for a spray foam roof to last 50 years?

Perhaps you’ve gotten this far, and you think spray foam might be a great product for you.

So how much does it cost?

While every scenario is different, the ballpark cost for installation is $4 – $6 per square foot.

There are a lot of variables that go into pricing, such as:

Your building’s location

The closer you are to a spray foam contractor, the less overhead there will be. It costs money to transport materials and labor to a job site. There is a difference if your roof is close to a contractor, or if you’re 2 states over.

How much material will be needed?

If there are no minimum R-value requirements, a minimum of 1” of foam can be installed (any less and the foam will not perform correctly).

Other roofing situations may need a certain R-value to target, like in some cases a roof may need to be an R-20.

With spray foam having an R-value of 6.5 per inch, more than 3 inches of foam would need to be installed.

More product = higher cost.

How long of a warranty are you seeking?

If you’re unaware, the length of the warranty is in direct correlation to the amount of coating that’s installed.

This is because the coating is sacrificial, meaning it’ll naturally wear away over time.

The more coating that protects the spray foam, the more costly it’ll be.

In most cases, here are the coating thicknesses and the warranty associated:

  • For a 10-year warranty, 20 mils of coating are installed.
  • For a 15-year warranty, 25 mils of coating are installed.
  • For a 20-year warranty, 30 mils of coating are installed.

More variables?

Learn more about the variables that influence the cost of a spray foam roof in this link.

Here’s a 50-year cost breakdown of a spray foam roof.

  • We’ll assume an average installation cost of $5.50 per sq. ft.
  • We’ll also assume the roof is 20,000 sq. ft.
  • We’ll assume the roof gets a 10-year warranty.

Year 0 (installation) – 20,000 x $5.50 = $110,000

Year 10 (warranty expires, need to perform a recoat, which is around $3/sq. ft.) = 20,000 x $3 = $60,000

Year 20 (recoat) = 20,000 x $3 = $60,000

Year 30 (recoat) = 20,000 x $3 = $60,000

Year 40 (recoat) = 20,000 x $3 = $60,000

TOTAL = $350,000

Now you’re at year 50!

NOTE: Most spray foam roofs come with a service contract. This will get a spray foam contractor on your roof twice per year. The cost is around 3 cents per sq. ft. For a 20,000 sq. ft. roof, the cost would be $600. Two service appointments per year would be $1200.

What are your next steps?

Here are some other posts that answer the most common questions about SPF roofing:

West Roofing Systems has been installing, servicing, and recoating spray foam roofing systems since 1979. Since then, there have been changes to the formulation that makes the foam, the introduction of granules that go into the top coating, more efficient equipment, and many other advances.

One thing that we always say is that any roofing system will perform right if it’s installed correctly.

The spray foam roofing cheat sheet - download now
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