silicone roof coating system

What Is the Process, Warranty, and Cost of Silicone Roof Coating Systems?

Greg PalyaSilicone Roof Coatings

Summary: The process is to determine eligibility and if a roof coating system is the right solution for the building owner’s problem. Silicone roof coating systems can be sprayed or rolled onto an existing roof. Warranties are usually granted for 10-20 years. There are many variables with cost, but it’s usually $4-$8 per sq. ft.

So, you’ve heard about silicone roof coating systems as an option to get your roof watertight and get a new warranty.

Perhaps now you have questions about how everything works?

In this article, we’ll answer:

  • What questions get asked in a discovery call?
  • What equipment is brought to the job site?
  • What prep work happens and how is it installed?
  • How long is the warranty?
  • What is the cost and what factors make the cost increase or decrease?

And just so you’re aware, West Roofing Systems has been in commercial roofing since 1979. We specialize in spray polyurethane foam roofing, which uses silicone roof coatings for protection from UV rays. Since around 2008, using silicone roof coating systems on their own has been an attractive, low-cost option for certain situations.

Every article written at West Roofing Systems is produced in-house and is reviewed and approved by a spray foam and coating expert with more than 30 years of experience.

Let’s get started!

If you’d like to see a video of a silicone roof coating project from start to finish, you can view the video here:

What questions get asked in a discovery call?

  1. How old is the roof?
  2. Is it leaking? How bad? How many different areas?
  3. Are the seams still attached or are they coming apart?
  4. What kind of roof system is installed?
  5. Is there routine maintenance on the roof?

All questions are geared towards eligibility and what’s the best repair option for the building owner.

For example, if there’s an unsmooth or ballasted membrane, the profile or texture of the roof will require an extraordinary amount of coating, making a coating system less cost-effective than other options. In this case, a spray polyurethane foam roof would be more cost-effective.

Or if the seams are completely blown apart, the seams are beyond repair and have also probably allowed a large amount of water to saturate the insulation. In this case, it’s probably beneficial to the building owner to completely remove the roof and install a new system.

Has there been routine maintenance on the roof?

If so, minor repairs (if needed) have been taken care of, leaving the roof in decent shape. If the roof has been neglected for 5 years, chances are the drains are clogged and tiny punctures or cracks have been allowing water to enter the roof insulation. If routine maintenance has been happening, it’s probably a great candidate to be restored with a coating system.

Let’s say there’s not too much leaking, the seams are in good shape, and the roof has been routinely maintained. It looks like it’s a great candidate to be restored!

Now you may think, what equipment gets brought to the job site?

What equipment is brought to the job site?

The only thing that comes to the job site is a box truck.

The box truck contains 55-gallon drums that store the coating.

The coating is pumped from the truck through a hose that goes all the way up the building and onto the roof.

The only thing on the roof is the hose, spray gun, and the roofers installing it.

If the coating is rolled (instead of sprayed), the coating will be pumped through the hose at low pressure, which we call “snaking out” the coating and then rolling it out.

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What prep work happens and how is it installed?

Clean existing membrane

The existing roof needs to be clean for the coating to adhere and cure correctly. This is usually done with power washing.

Any wet insulation is removed and replaced

Core samples or an infrared scan will identify wet insulation that’s underneath the membrane.

Damaged areas of the existing membrane are removed and replaced

For example, say there are cracks, cuts, or punctures in a TPO roof. These areas would need to be removed and a new TPO section would be installed.

Adhesion test

Tests will be performed to make sure the coating adheres and cures correctly to your roof’s membrane.


Sometimes a primer is needed to get proper adhesion for the coating.

Seam enhancements/reinforcement

Seam treatment is very important as the seams are areas that break down the fastest on any roofing system.

When a roof expands and contracts, it’s the seams that take the most stress.

To give the seams extra strength, a coat of silicone is applied, then a fibered mesh is installed into the wet coating to all horizontal seams. Some smaller penetrations will receive silicone sealants.

A heavy coat of silicone coating is then installed over the mesh.

Add the proper amount of coating to the rest of the roof

The proper amount of coating is dependent on the desired warranty length.

  • 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

What is the cost and what factors make the cost increase or decrease?

The ballpark cost of a silicone roof coating system is $4 – $8 per square foot. This range can change on a daily basis with fluctuating material costs, gas prices, and labor shortages.

Here are some factors that increase or decrease the cost:

Amount of tear-off

Some roofs have 20% of their insulation and membrane that needs to be removed and replaced. Others have 2%. The more tear-off and replacement, the more the project is going to cost.

Size of roof (economies of scale)

It’s like buying 1000 rolls of toilet paper at Costco. The cost per roll will be cheaper when you buy 1000 than when you buy 10. There’s a certain level of overhead that goes into any job that becomes less and less of the project cost as the size of the project increases.

Duration of warranty

A 10-year warranty requires 20 mils of coating, while a 20-year warranty requires 30 mils of coating. More material increases the project cost.

Location of the roof #1

Any roof location where overspray can become an issue (such as dealerships, airports, shopping malls), the coating will most likely need to be rolled instead of sprayed. The speed of installation is slower when rolling, so that could result in a slight increase in project cost.

Location of the roof #2

Travel costs increase the further away you’re located from the roofing contractor.

Would you like to learn more?

Hopefully, after today, you got a better idea of what the process, warranty, and cost of a silicone roof coating system are.

If you’d like to learn more about roof coating systems, here are some articles:

West Roofing Systems has been in commercial roofing since 1979. We’ve been using silicone coatings to protect spray foam roofs since 1979. And we’ve been using silicone coatings on their own as a source of roof restoration since 2008.

download the silicone roof coating cheat sheet

About the Author

Greg Palya

Greg Palya is the Digital Content Manager of West Roofing Systems, Inc. He has a B.S. in Marketing from the University of Akron and an MBA in Marketing from Walsh University. When he's not trying to teach others about spray foam roofing and silicone roof coatings, you can find him on the basketball court or golf course.