What is RoofNav and how does it assist roofing professionals?

RoofNav provides easy access to the most up-to-date FM Approved flat roofing-related information and installation recommendations from relevant FM Global Property Loss Prevention Data Sheets.

It allows a range of roofing professionals including contractors, specifiers, procurers and installers to search for flat roofing assemblies that match the particular criteria required by their project. This is a quick and easy way to focus in on those systems that demonstrable performance and make selection of the final specification reassuringly simple.

The flat roofing build ups undergo very thorough testing. This is designed to satisfy the requirements of the insurance industry, where the focus is on selecting robust and resilient roofing specifications to reduce the potential financial loss to a business. This is different to building regulations/code, as they focus on safety and performance and are not so concerned with the impact of business interruptions.

This means that assemblies listed in RoofNav have been tested to generally higher standards than would be the case for regulatory purposes. This gives extra reassurance to those professionals who use RoofNav to specify flat roofing assemblies for their projects as they can choose from a list of robust and reliable roofing build-ups for their project.

How do assemblies get listed on RoofNav?

Roofing assemblies only get listed on RoofNav after they have undergone extensive testing by FM Approvals. This assessment is carried out on the whole assembly to see how well the roof will cope against a variety of threats that could compromise its function and performance.

The roofing assemblies are tested for their resilience to:

1. Fire from outside the roof
The external fire test uses the ASTM (American Society for Testing & Materials) test ‘E108’ where a fire on the outside of the roof is simulated with a wind blowing at 12 miles per hour. Roof assemblies can be tested either on combustible or non-combustible decks and there are several tests that can be carried out:

1. Spread of flame test
2. Intermittent flame test
3. Burning brand test
4. Flying brand test

The tests required are determined by the nature of the deck, either combustible or non-combustible, and the type of waterproofing chosen. Once testing has been completed the assembly is awarded one of these 3 classifications:

• • Class A – effective against severe fire test exposure
  • Class B – effective against moderate fire test exposure
  • Class B – effective against light fire test exposure

2. Fire from inside the roof
This is an exclusive test used by the FM Global insurance company to determine the contribution that the roof would make to attack by fire from inside the building. The possible classifications for the roof assembly are:

• • Non-combustible (concrete deck)
  • Class 1 – ‘limited combustible’ roof assembly
  • Class 2 – ‘combustible’ roof assembly

3. The Effects of the weather
There are several ways in which the effects of the weather on the roof could cause damage that may affect its ability to offer vital protection to the building below. Wind blowing across the roof creates areas of low pressure that effectively try to ‘suck’ the roof up – usually referred to as ‘wind-uplift’ and roof assemblies listed in RoofNav all undergo wind-uplift testing.

If a roof is damaged by wind, this can expose the contents of the building to the elements. An FM Global survey over a ten-year period, showed that failure of the roof was the root cause in 80 per cent of the losses to businesses due to wind damage.

Other weather-related testing carried out by FM Approvals includes water ingress through the assembly, damage to the waterproofing layer by hail and the resistance of any metal components to corrosion.

Once all the testing we have just looked at has been completed, the assembly will get listed onto RoofNav with details of how it has performed. This enables roofing professionals to use RoofNav as a useful tool to select only those roofing assemblies that meet the particular criteria required for their project.

4. Damage caused by foot trafficking or falling objects
Damage to the roof can be caused by the weather, where objects blown by a storm hit the roof. However, much of the testing that the assemblies undergo in this case is also to test for resistance against damage from self-inflicted sources when the roof is maintained or repaired. Frequent foot trafficking can compress the waterproofing layer and compromise its integrity. Any dropped tools or equipment when work on the roof is undertaken can puncture the surface and potentially cause damaging leaks. Therefore FM Approvals test for both resistance to foot trafficking and damage by puncturing as part of the suite of tests.

Once all the testing we have just looked at has been completed, the assembly will get listed onto RoofNav with details of how it has performed. This enables roofing professionals to use RoofNav as a useful tool to select only those roofing assemblies that meet the particular criteria required for their project.

What does a product listing in RoofNav tell you about the manufacturer?

If a manufacturer has a product listed in a roofing assembly, it shows that it has contributed to the overall rating of the roofing system when tested. The scale of that contribution will depend on the nature of the product.

In the case of roof boards and roof cover boards they can enhance the fire resistance, wind uplift resistance and water proofing abilities of the roof. Searching RoofNav will show that they appear in many listed roofing assemblies. As an example, of the 1,231,5351 different roof assemblies with all types of waterproofing finishes, over 59 per cent contain a roof cover board.

Can manufacturers have individual ‘FM Approved’ products?

Yes, there is a separate process for manufacturers where they can put an individual product through a FM Approvals testing and verification procedure to allow it to become ‘FM Approved’. These ‘FM Approved’ products may also appear as part of tested assemblies in RoofNav.

It is important to note that products that appear in a listed RoofNav assembly cannot themselves claim to be ‘FM Approved’. They form part, along with the other assembly components, of a rigorously tested and approved assembly, however, that does not mean that they would pass the testing required to gain individual approval.

At Georgia-Pacific our DensDeck® Roof Board range of products are both individually FM Approved and are also listed in RoofNav assemblies. In fact, DensDeck® Roof Boards are the leading brand of listed roof and cover boards in RoofNav with 398,868 entries¹.

Our products have been rigorously tested both individually and as part of many assemblies giving maximum peace of mind when selecting DensDeck® roof or cover boards for your projects. If you have any questions on how to use RoofNav or about our FM Approved products, please contact one of our team today.

¹ Audit carried out on 16th August 2023