Roof warranty submitted for much lower wind speed than performance indicated

Specification & Product Discussions Construction Contract Administration Discussions
1

Has anyone else started to encounter this? Masterspec’s technical sections appear to be weak on tying warranties to performance requirements, so we are concerned this may be new feeding ground the industry is turning toward. Scenario:

A supplier argues that the warranty paragraphs in the roof membrane specification section only indicate a 20 year warranty period and failures to be covered, so they think the wind speed of the warranty (submitted with 55 mph limit) does not have to be the same as the wind speed indicated for the system (133 mph – however they are at least providing a system that is tested to meet the uplift rating indicated).

When does a “warranty” cross an invisible line and become no longer a warranty, and instead become a disclaimer that only takes away the rights the Owner would have with no warranty at all?! I think this one is crossing that line even more than the usual ridiculous disclaimers in the fine print. Couldn’t a 55 mph storm could easily be documented just about anywhere on the map? Future leaks might be attributed to that storm, thereby making the warranty of no effect. Is this simply a way they can say that leaks are no longer covered? Nice that it says “Warranty” in fancy letters at the top though! :wink: They appear to be claiming that any warranty will do. If that were true, someone could write “Warranty” on a napkin and submit it!

Of course we have rejected the submittal already on the basis of inadequate warranty, but I’m getting prepared to refute the likely follow-up C/O they might say is needed to upgrade to the right warranty and provide “system enhancements”.

Masterspec’s 016000 Product Requirements section helps us out some with this, but I am looking for something that also puts the manufacturer on the hook. It sounds here like it is just the Contractor: “Manufacturer’s disclaimers and limitations on product warranties do not relieve Contractor of obligations under requirements of the Contract Documents”. Several paragraphs go on to say more about special warranties and modification of forms.

Breaking this down, we could ask: Is the wind speed a requirement of the Contract Documents? Yes it is. The structural drawings give that information on Sheet S100. Therefore, it appears that the Contractor must provide a system and a modified warranty that fully meets the spec. If they do not, I suppose the Contractor, not the manufacturer, would have the liability on themselves if there is any failure in that roof for the next 20 years.

This is the only time I recall starting to prefer SpecsIntact/UFGS’s language. All of Masterspec’s 7 paragraphs seem to be summed up in one sentence: “Revision or amendment to standard full system membrane manufacturer warranty shall be provided as required to comply with the specified requirements.” If only they’d stop being so “shall-ow” (shall be this, shall be that), which is also dangerous because it does not say who shall. I guess even there we would still be in the same dilemma. Reading some other threads, and knowing how the real world works, I recognize there is normally not much attention given to warranties until closeout.

Just hoping to find clear grounds to ward off a C/O for this.

2

To my knowledge, the wind speed exclusion in roofing warranties has been historically at a much lower speed than the wind speed for which the system is designed. Of course, there is a wide range of possible damage before a total blow-off of the roof occurs, so repair costs are not necessarily extraordinary even in a very high wind event. Here in Boston, we have a design wind speed of 100 to 110 mph, yet we rarely have storms that even approach that speed. A storm with even 70 mph winds would be a really big event.

Manufacturers will often increase the maximum wind speed for the warranty, but there is a cost associated with that. I think if you were to request a warranty for the design wind speed, the owner may not want to pay the added cost of such a warranty. Insurance, depending upon the coverage the owner has, would also pay for replacing a roof. The point is, what do you expect the warranty to be? Is it insurance? Or is it only an assurance of a reasonable level of quality in the roof? I have always felt that the cost of an extended warranty would have a better pay-off if it went to installation observation services.

3

John as usual has it correct. The level of gale force winds (55 mph) is the typical threshold for roofing system warranty coverage. We sometimes amend this to the 74 mph hurricane wind threshold, after which it is assumed that the owner’s property insurance takes over. This should be considered before writing the specification, as the property insurance may be providing duplicate coverage above 55 mph.

The design wind speed is not typically the threshold for warranty coverage. Looking at the UFGS section Chris mentions, the warranty text merely references normal climatic and environmental conditions at the project site, and requires a warranty against failure due to material or workmanship failure, not roof blow off due to high wind conditions.

So even though the installation may be required to correspond to that assembly which has been tested to UL or FMG wind uplift standards or engineered to ASCE-7 standards, the manufacturer’s responsibility is limited in high wind events to failures that result from non-conforming materials or workmanship.

Chris’s idea of expressly writing to a higher wind level to avoid later disclaimers due to there having been a previous high wind event is worth considering. Very important here will be a typical manufacturer requirement that the roof be inspected following any high wind event, something owners often fail to do.

4

The building code has undergone a change in the way wind speeds have been defined. Under the UBC where I live was classified as 70 mph fastest mile. The IBC currently classifies it as 85 mph 3 second gust. Proposed changes for the 2012 IBC introduce maps that would show the ultimate design wind speed as 100 mph at my location. The wind has not changed it is just the way we define it.

Note that I live near San Francisco and we do not have hurricanes here.

My question is that when specifying wind speeds which of these ways of specifying wind speed are the roofing manufacturers and the property insurers using. It would not surprise me if they were lagging the current codes.

My concern is that the wind speed the Structural Engineer places on his drawings to satisfy regulatory requirements may not necessarily be in the form others need.

To further complicate things the wind uplift pressures can vary significantly for the same wind speed depending on the configuration of the roof, the height of the building, and the surrounding topography. Thus relying only on the wind speed to define the risk may give people a false sense of security.

ASCE 7-05 just specifies the wind speed and pressures to be used in design. ASCE 7 does not define how to attach the roofing assembly. Chapters 19 through 23 address how to design the structural elements of the roof but again not how the roofing is attached.

5

If using the FMG Approval Guide to establish roofing performance levels including wind uplift and several other characteristics, FMG Loss Prevention Sheet 1-28 is used to factor in those variables that Mark identifies: configuration, height of building, and surrounding topography. These variables are assigned coefficients that adjust the basic wind uplift pressure in order to arrive at the final FMG rating, which is not a direct identification of wind speed but a pure number.

Thus simply grabbing FMG 1A-90 may not be appropriate for a project in a location where design wind speed is identified as 90 mph. And Mark’s comments indicate that even identifying the design wind speed is not so simple, and subject to change. Design wind uplift pressures have a significant affect on the cost of the roofing system.

6

I also regularly write requirements for roofing warranties to 74 mph (since I do projects in hurricane country). However, in considering all of this, you should remember that at higher wind speeds, you are likely to have “stuff” blowing in the wind. This “stuff” can, and sometimes does, cause damage to the roof membrane in the form of tears and punctures. In this case, your client is not covered by warranty, but by insurince. You can get coverages for higher windspeeds (with much cajoling, whining, and a big enough 2x4), but it is highly likely that if your roof has been designed for the right uplift requirements and installed as designed, wind damage will be from debris, not from wind uplift. This will not be covered no matter how big your 2x4 is.

7

Am trying to find the source of the 74 mph number. On Wikipedia I found a table that related Beaufort scale to various wind classifications. In this table 74 mph was the start of Beaufort 12. Hurricanes start at Beaufort 11 which is 64 to 72 mph(73 mph is missing?). The only problem is that these wind speeds are defined as 10 minute averages.

76 mph (fastest minute) corresponds to 90 mph (3 second gust) Thus 74 mph (10 minute sustained wind) would be greater than 90 mph (3 second gust).

Thus if you specify 74 mph without clarifying the basis you may have only asked to be protected against a mid level tropical depression. Similarly the 55 mph may correspond to a tropical depression.

8

Thanks to all for the comments. I was called on to help interpret a specification someone else had written, with a short time-frame for getting back to our CCA, so I really appreciate the insight and perspective.

I have seen many project specifications that use the 74 mph threshold in a sample warranty at the end of the section, even though the design wind speed is considerably higher. I have also seen some projects that specifically use the design wind speed, ranging from 100 mph to 140 mph (depending on type of roofing), restating it in the sample warranty. Based on the amount of variation between warranty wind speeds and design wind speeds, and no direct requirement in the specifications, perhaps it will be better to go a little easy on them for submitting 55 mph, but it still seems ridiculous in this location.

To my recollection none defined the method of calculation. I will try to find out in upcoming discussions with Versico if they know what method they use.

9

Two of my most recent data center projects are insured by FMG. One is in GA and one in western WA. The GA project has absolutely no roof top equipment (all placed on grade), whereas the WA project is loaded (no room on grade).

GA has been affected by hurricanes that hit Florida. Both the Owner and FMG required the basic wind speed of 150 mph as if the project was in Miami/Dade County. Performance requirements for wind uplift list the raw pressure (NOA) for the field, perimeter, and corners and the FM equivalent for each location. Clients consider these essential facilities due simply to the massive liquidated damages incurred from down time.

The manufacturer’s Guarantee states: Prior to acceptance of work, furnish manufacturer’s written 20 year no dollar limit guarantee executed to the Owner. Guarantee shall cover FM Performance requirements listed above including materials and workmanship, and shall cover roofing membrane, adhesives, flashing, coverboard, insulation, and air/vapor barrier.

The projects are nearing completion. The wind speed and design pressure specified have never come into question by the manufacturer or GC or roofer.

In fact. the manufacturer assisted in the preparation of the roofing specs for each geographic location. The manufacturer calculated the anticipated wind uplift pressures based on their internal ASCE 7-05 calculator.
Building Height = 30 feet
Exposure Category = B
Importance = 1.15
Wind Speed = 150
Enclosure = Enclosed.

Wayne

10

The first step is to determine the frequency of the event you wish to design for. In Waynes case this translated into a basic wind speed of 150 mph (3second gust). In many cases I believe that people will default to the basic wind speed listed in the code.

Next you need to determine the wind pressures. I would be cautious of the manufacturer’s calculator since it may be too simplistic and miss some of the nuances. You need to have a dialog with your structural engineer.

Finally the roofing contractor/manufacturer needs to determine the roofing system and type of attachment that will comply. The roofing system and method of attachment needs to be qualified by testing. This approach will give you the best likelihood that the roof will perform as expected.

Specifying the wind speed may make it easier to hold the manufacture liable if there is a problem but it has a couple of problems. First you need to be specifying the wind speed clearly but it appears that there is a lot of confusion in the industry. Secondly the manufacturer will need to determine the wind pressures but I am concerned that they will have a tendency to use simplified calculations thus under estimating pressure in some locations.

11

Add one requirement to performance criteria for roof assemblies on projects insured by FMG and XLGlobal. Both require a RoofNav #. FMG was particulary sticky in this requirement. We learned not all manufacturers have RoofNav #'s for their various assemblies and some manufacturers are not willing to spend the time and $ to create a RoofNav # just because FMG demands one. This will not prevent the roof system manu from obtaining FMG approval but it does slow down the submittal process as the paperwork flows back and forth till FMG is happy. In the sticky case, FMG became the insurer after the fact and it strung out the process. At least one well known worldwide manu objects to providing RoofNav #s when all their permutations and combinations of product were FMG approved under the previous system. To the layman, RoofNav #'s look like gibberish.

12

Just out of an informative, but “messy” 3-hour meeting over all this.

Best advice-- get a roofing manufacturer person you trust and get them involved in navigating the whole of the FM process.

Not worth the time, anguish and risk involved in trying to do this alone, no matter how astute you are.

13

Was stung by this once. Had a roofing failure - membrane pulled off substrate. Warranty submitted and approved was for 55 mph. On the date that the blow off occurred, a nearby airport recorded winds up to 58 mph. One of the major roof manufacturer’s was involved and pointed to the +3 mph on the date of occurance. Got a good roofing consultant involved and ultimately the manufacturer contributed significantly to the replacement. However, in working with the roof consultant and manufacturer’s reps since then, it has been noted that if you want a warranty for more than 55 mph that it should be specifically specified. There is a std. for high wind speed, but I do not recall off hand what speed that covers. Most “master specifications” have the language “manufacturer’s standard warranty” which is the 55 mph.

14

FYI-- A few years ago we worked with a major roofing manufacturer, via a roof design seminar, and were advised to use the following in our warranty criteria.:

Provide warranty coverage for ground wind speeds of 72 mph, minimum, as measured at 10 meters above ground level.

15

Blast from the past - I think Ralph had it right on the 72 mph because I just arrived at the same thing. It is a several step process to get there. I’m hoping with a little more help I can see if I’ve done all of this right, so here goes. (In other words, this is just hashing things out on a forum - I am NOT an insurance or legal adviser, so don’t take any of this out of context!)

As an example, Firestone’s standard warranty exclusion is “Winds of peak gust speed at or in excess of 55 MPH calculated at ten(10) meters above ground using available meteorological data”. This is like I recall from Versico in 2009 that started this thread, and a couple other posts here so it must be fairly typical “standard” wind speed warranty, and of course you can pay for more. This led me to wondering, could I find out where insurance companies start covering, and how they measure wind speed in case there are any differences.

There may be a general consensus of 45 mph being when insurance could kick in but their measurement as well as weather reporting of storms generally goes by 1-minute average though, not 3-second gust like structural calculations and unfortunately not like the manufacturer’s warranty either. See these resources:

http://www.theinstitutes.org/MediaCenter/docs/articles/Kearney_WindstormHazards.pdf - Susan Kearney, CPCU, ARM, AU, AAI, Senior Director of Knowledge Resources for “The Institutes”, which is the Insurance Institute of America and the American Institute for Chartered Property Casualty Underwriters.

https://www.wmo.int/pages/prog/www/tcp/documents/Doc2.3_WindAveraging.pdf - World Meteorological Organisation - Guidelines for Converting Between Various Wind Averaging Periods in Tropical Cyclone Conditions

In the 2nd link, see page 13 of the PDF (marked page 4). They give an example of 1.36 for converting off-shore winds at a coastline, from 1-minute average wind measurement, to 3-second gust wind measurement. You can find this in the table. Then look up to see how you would convert in-land (open terrain is all they give us), which is a 1.49 multiplier! I suppose it goes up because at the coast and especially at sea, there are just about always windy conditions. Inland, things can be a lot more variable between 3 seconds or a minute of maximum wind speed in a storm.

So even though the insurance may start coverage usually at 45 mph, that is 1-minute average sustained wind. Multiply 45 mph by 1.49, and you find that in the peak gust terms that roofing mfrs use, the insurance wont kick in until approximately 67 mph and nobody has the weather data to say for sure thats what it was for the incident, but that leaves about a 22 mph gap! Maybe that is why engineers can even be needed for analysis of the damage in a storm. I hope I dont screw up the calculations, and they are only approximate but it is still way closer than not knowing and thinking it is all the same.

So if a 55 mph warranty leaves a 20 mph gap where the owner might not be covered either by a roof warranty or insurance, let’s see what warranty WOULD likely cover to where there is no gap. Looking at Firestone’s warranty pricing guide the first level of extended wind speed coverage is… 72 mph (like Ralph said). That’s just above the 67 mph we calculated earlier to express the weather reporting data used by insurance underwriters converted to the measurement used by the roofing manufacturers.

Now, what does it cost to bump it to 72 mph? Or put another way, how much could the owner save by not being covered in a medium-bad storm? And would they want to do this? The warranty pricing guide helps start to answer this. As an example, if you have a 20 year 55 mph warranty for the full roofing system (commonly used choices in specs) it comes out to 10 cents a square foot. If you bump it up to 72 mph, it is an additional 10 cents a sq ft. There are minimum dollar amounts though. So for a very small building it is a few hundred dollars, for a medium sized roof it could be a few thousand dollars, and on up.

It sounds like that is a lot of money. How about if the owner is unexpectedly stuck with the cost of repairs? Very few buildings do not matter if they leak, or you wouldn’t have a building. Maybe if it is a car wash!

The owner would have to draw their own conclusions based on project location, wind speed, size of the building, their budget, and their tolerance for risk.

Unfortunately because of the differences in measurement it is trickier than it seems like it ought to be. I guess it all comes down to what your definition of wind is. Another blast from the past: https://www.youtube.com/watch?v=-P8IYKxpqG0

16

I’ve always found it interesting that roof warranties are limited to windspeeds that are lower than the windspeeds required by the building code.

Per the 2009 IBC, the 3-second gust is 90 mph for most of the US, with a coverted fastest mile at 76 mph–both are higher than most typical roof warranties. In the 2012 IBC for Risk Category II buildings (common for most structures), the 3-second gust increases to 115 mph with a converted windspeed of 89 mph.

17

The wind speeds typically called out in a roof manufacturer’s limited warranty are related to the National Weather Service’s adaptation of Beaufort Wind Scale definitions for wind speeds classified as “Storm” (>55 mph), “Violent Storm” (>64 mph), and “Hurricane” (>74 mph). Damage due to sustained winds under those classifications ought to, by definition, be covered by property insurance as storm damage. If the warranties didn’t limit coverage beyond those wind speeds, insurers could come back to manufacturers under subrogation. Roofing manufacturers aren’t trying to stick it to their customers, they’re just trying to limit their risk to what is necessary to protect the original purchaser. When we insist on higher covered wind speeds, we are just giving additional protection to the insurer at the owner’s expense.
In contrast, wind speeds in building codes are set to protect lives by making buildings sturdier. We ought to set the bar higher for that goal.

18

I am going to repeat myself by noting that at the higher windspeeds, you are more likely to incur damage from wind blown debris (especially less than 50 feet above the ground). No one’s warranty will cover that type of mechanical damage; you have to go to the insurer.

19

Rick I would go with that and it would be simple, except for that multiplier of 1.5 between how the NWS measures (1-min average) and how the manufacturer’s measure it (peak gust, same as 3-second gust?)

This is significant, and is why I still suspect there is a 20 mph gap where in some cases neither the insurance nor the warranty covers a 55-mph warranted project. Hope I’m wrong!

The debris is an interesting point too Peter. Lots of factors, none of which make it easier.