cool roofs

Industry Gossip: Solar PV Roofing (IB-PV Roof) Failures

The word on the “roofing contractor street” is such that a large PVC roofing manufacturer has problems with their Roof-integrated Solar PV systems. Apparently, the way they designed and installed these solar roofs, the electrical wiring which connects Solar PV panels to the inverter and essentially to the Electric Grid, is overheating and poses serious risks of fire. Since this information is still in rumor stage, and I doubt there will be an official announcement or acknowledgment of this, I for many reasons cannot name the manufacturer, the specifics of the problems or the source. However, there is evidence that it is real. If you are a large roofing contractor in Boston, MA area or in the rest of New England, you are getting the roofing bid lists, such as the Blue Book. Large commercial and government roofing jobs are a little out of our league, and we get plenty of work without paying huge sums of money for these bid lists (it costs anywhere from $3000/year to get periodic updates). However, in the last 3 weeks I’ve been contacted twice by two different gentlemen from Suffolk Construction. Basically Suffolk is arguably the largest GC in Boston area with $1.57 Billion in sales in 2008, has over 800 employees and are rated #313 of America’s Largest Private Companies by Forbes.

The picture below, shows a Solar roof produced by IB roof systems. This roof does NOT have overheating problems, and is intended to demonstrate what Solar Roofing is.

IB SolaWise roof integrated PV System

In any case, the two gentlemen from Suffolk, asked me to bid a new job in the pipeline of roof bidding lists:  A 4,000 squares (400,000 sq. ft.) on the IRS building in Andover, MA, and also they wanted 500 KW solar PV system that would be roof integrated – essentially they were interested in our IB Solar Wise PV system, which in some ways is similar to the one above, but without the wiring overheating of course 🙂 Continue reading

CoolFlatRoof.com moved to Blog / CSM platform

Dear visitors, It is my pleasure to announce that our main site – www.CoolFlatRoof.com – is now officially running on the awesome WordPress Blog / CSM platform, which makes it run faster and offers you, our visitors great usability and ease of finding information about Flat roofing, Metal roofs, Green roof top gardens and Solar PV roofing systems. New website features include:

  • Extensive Site-wide search. With over 30 different articles about cool flat and metal roofing it used to be difficult to navigate to the right page. Now, all you have to do is type what you are looking for into the search box at the bottom of the side-bar, and you will find what you are looking for.
  • Comments & Feedback. You can now leave comments about every article that we have and also subscribe to those comments (you will get responses by email). I personally answer most of the comments you leave on our blog, and will do the same for the comments on our main site. As always, please respect us and our readers and do not post offensive commentaries. All comments are moderated by a human and all spam gets filtered. If you post a genuine comment or question, it will post and I will answer it as best as I can.
  • Blog Roll / Green blog links: If you are an author of a green or renewable energy related blog, I welcome you to add us to your blog-roll, and I will do the same.
  • Publish your green articles here: If you want to write about anything related to green construction and renewable energy, I welcome you to become one of our Authors / Contributors. You can post relevant links to your own site or blog, which will help you promote your site with search engines such as Google, Yahoo, Bing and others.

These are just few new options that a new platform offers to make your search for roof related questions easier and more pleasant. Just a few roof related articles you may consider interesting:

IB Flat Roof: “A good roof is the one you can forget about” – such is the moto if IB Roof Systems – a great roofing materials manufacturer, who’s single-ply membranes we use exclusively for ALL our flat roof installations. We use IB roofs, because we as a contractor know that once installed correctly, an IB roof will outlast any conventional flat roofing system by 2-3 times. With a proven track record of 30+ years of real life, leak-free performance, IB roofing systems have nothing else to prove. An IB roof is a cool, truly sustainable roofing system that can be used for Green Roof-top gardens, Solar roofing and conventional flat roofing application in both residential and commercial markets.

Flat Roof Repair: Learn what to do when your flat roof begins to leak, how to choose a roofing contractor, what a roof repair will cost you and whether your should repair or replace your roof.

IB Roofing prices: Learn how much it will cost you to replace your old roof with an IB Cool Flat Roof.

EPDM Rubber Roofing: Discover the truth about rubber roofing materials, scam contractors that install residential rubber roofs without proper training / experience, and why you should definitely avoid these “super roofers”, and the inferior rubber roofing materials all together.

Rubber roof repair: Learn DIY techniques involved in fixing your leaky EPDM roofing system. This guide includes a complete list of tools & materials you will need and step-by-step instructions for Do-It-Yourself homeowners.

Home Solar systems: Comprehensive guide to designing, implementing and installing a Solar PV System on the roof of your home or small business. Lear now to position your solar panels, which inverter to use and how to minimize power losses, maximize Solar PV efficiency, and make your solar system pay for itself in as little time as possible.

These are just some of numerous informative and practical guides that we have created to help you solve your flat or metal roofing problems, find information on roofing materials and contractors. Let us know what you think of the new platform, the design of this site, and how we could make navigation / usability better and more comfortable for you. Enjoy! Sincerely, Leo – CoolFlatRoof.com

Single-ply Flat Roofing Systems: PVC and TPO

If you are a building owner, facility manager or even a homeowner with a flat roof that leaks, and you are interested in or got a bid from a contractor to install a new flat roofing system called TPO (Thermoplastic olefin), this is a must-read article for you, because you will not find this information anywhere else.

From The Editor: – this post has 50+ VERY interesting comments from “both sides of the aisle” so to speak. We highly recommend you read these comments, after the post.

Foreword: TPO is a hot-air welded thermoplastic single-ply roofing membrane produced by numerous manufacturers. TPO was created to be better than EPDM Rubber roofing and cheaper than PVC roofs, while it would still provide all the benefits of hot-air welded seams. It was a good plan, and now TPO membrane covers billions of square feet of roofs and represents a multi-billion dollar roofing market, but there are some problems…

In it’s fairly short life (about 15-16 years) TPO went through at least 2 generations. 1st generation of TPO roofs began to fail in the late 1990’s and early 2000’s. Now, some manufacturers are on their 3rd generation (or major reformulation) of their TPO products. At the same time, TPO’s main rival – PVC roofing membrane such as IB Flat Roof, has not changed its formula in over 30 years.

The video clip above below a brand new TPO roof burning on a roof of a new office building that was built in Salt Lake City, and filmed by the Fireman crew.



Why you should not get a TPO roof – TPO roof on fire video

Whether you are a customer looking for a new flat roof or a roofing contractor, I recommend that you to do some serious research on TPO before investing in it. This will serve your own benefit.

To start, you may want to check out the WSRCA (Western States Roofing Contractors Association)  “TPO roof study” – http://www.wsrca.com/bookstore/index.htm.

WSRCA’s test roofs in Las Vegas, NV, Anchorage, AK, San Antonio, TX, and Seattle, WA demonstrate the product service life in diverse climates throughout the western United States. All have weathered past the four year mark, and the results are now published.



The problem is that for some reason they pulled off 2007, there is still no 2008 edition and only a 2 year old report from 2006 is available. But here is the “rumor” from trusted sources:

TPO roofs in the above study lose minimum of 1 mil of thickness per year and some TPOs lose as much as two mil per year (in 10 years that will be 20 mil – imagine that on a 45 mil membrane). The average top ply thickness is 15 mil – some are 12. Once you are down to the scrim, the roof is gone, and the UV will eat the scrim and bottom ply.



Also, there are problems with seam failures, premature curing, cracks along the seams, etc. These are TPOs made in 2001-2002 (second generation) Supposedly there is no 3rd gen. going into production, and I suspect that the reason for the 2007/2008 edition of this book not being available is because manufacturers pressured WSRCA to pull those off. I could swear that I saw an ’07 edition available on sale in January ’09, and now its not even listed.

Aside from the above, most TPOs and maybe some PVCs (to cut costs) come with a wicking scrim, so you need to do something about the edge of the weld – that is like welding twice, and there is still lots of room for error, and once the water gets to the scrim, it will delaminate the membrane… I don’t need to explain the consequences.

So, the bottom line – do you want your customers to have a 2nd/3rd gen. of repeatedly failing roof technology and put your reputation on the line for a gimmick created by greedy roofing manufacturers, who are looking for ways to reduce costs at the expense of quality (putting cheap fillers into membrane to create nominal thickness)? What is the difference between 45 and 60 mil TPO if weathering surface is 12-15 mil? Just a thicker bottom play that is made of junk in a first place.

Another thing that amazes me about TPO is the peel-n-stick seams. WHY?… The whole point of thermoplastic roofs (PVC & TPO) is the hot-air welded seam… EPDM rubber roof can be peel and stick… but TPO? All it does, is attract hacks into thermoplastic roofing market. Those who do not care about quality install, fly-by-night dudes, etc. I mean, if you as a roofing contractor go and spend $10-20K on the hot-air welding equipment you probably won’t disappear tomorrow, as you need to pay for that equipment and make some money on top of that. You as a roofing contractor are probably in it for the long run…

Instead of conclusion:

As I mentioned in the beginning of this article, the idea of a TPO roof is great. A cheap, naturally cool, long lasting flat roof system featuring hot-air welded seams is something of an ideal for the roofing industry to strive toward. However, the “cheap” part in TPO is why all these roof failures occurred, and will be happening on a wide scale in the near future. TPO’s problem is not the faulty design. In Europe, TPO has been around for decades and is considered to be a very good flat roofing system.

However, here in the US, roofing manufacturers put the bottom line in their accounting books above product quality and interest of their clients by manufacturing their TPO membrane using primarily cheap fillers and low quality wicking scrim, without proper testing or acquiring UL certifications. In the end, roof owners and to some degree roofing contractors become victims of corporate greed and irresponsible business practices.[PSGallery=1ondfvgxk]

Flat and Low Slope Roofing on Shed Dormers

Discover a permanent solution to leaks on shed dormers and other flat roofs

IB Flat Roofing on a shed dormer roof in Andover, CT

Many homes in New England have shed dormers, which are build to use otherwise unusable space in the attic, and greatly expand square footage of the home, without huge expenses of building an addition. However, the way these shed dormers are built, requires them to have a very low sloped roof, at times almost flat. These roofs are the first to leak, as conventional roofing materials cannot stand up to the Ice Dams build up and wind driven rain water, penetrating the roof between the seams in shingles and rolled roofing products.

This low slope roof had been patched many times around the chimney and along the eaves, and even with the Ice-melting cables, the Ice dams and leaks could not be stopped.

The problem with shed dormer roofs is that often asphalt shingles or rolled roofing materials are used, and the seams on such roofs are held together with adhesives – usually tar that melts under the sun’s heat and seals the seam. When asphalt shingle is used in such roof assembly, the joints between the shingles and the overlaps between them are an easy way for water to penetrate the roof. In the winter, moisture between shingles freezes, expands and breaks the seal. At this point, the roof leaks constantly, and no matter how many patch jobs you do, it will still leak. Also, a low slope on the roof greatly shortens the life of the shingles. Not to mention that when shingles are installed on a pitch of less than 3 in 12″, the warranty is immediately void on them.

While many roofing contractors will try to convince you that with the use of Ice & Water shield such as Grace (considered by many to be one of the best I/W shield products),  will make your roof water-tight and leaks free, real life experience shows that even on a steeper slope, such as 3 or even 4 in 12, the roof still leaks, and Ice dams leaks find their way inside your house.

This lake front home in Andover, Connecticut has a rolled asphalt roof that has been patched multiple times and still leaks.

A metal roof could be used to solve the constant roof leaks and ice dams on such low slope roofs, but in this particular case (the picture above), the pitch of the roof is too low for even a standing seam metal roof to work, and the best solution in this case would be an IB Flat and Low-slope roofing membrane. Besides, standing seam would cost double of what an IB flat roof cost would be.

Another solution commonly used by residential roofing contractors is the rolled asphalt roofing, or simply rolled roofing. Please keep in mind that most flat roofing systems come in rolls, but each type has it’s own trade name, such as Tar & Gravel, Rubber roofing, etc., and rolled roofing usually refers to a fiberglass membrane saturated in asphalt and asphalt, and coated with stone granules – very similar to asphalt shingles. Learn more about different types of flat roofing materials. Rolled asphalt was a popular choice for DIY roofing projects and many residential roofing contractors would use it, as it was fairly easy to install and easy to buy from a local roofing warehouse, without any special training involved. Unfortunately, these roofs only last about five years, and often begin leaking even sooner, causing expensive to repair structural damages, such as those shown in the picture below. Because the seams of rolled asphalt roofing are sealed with roof cement and fastened with roofing nails right through the membrane, the condensation below and the ice above the rolled asphalt quickly break the seal and the roof begins to leak. Patching such a roof will temporarily stop the leak, but it will actually create more damages, as in the meantime you allow water more time to destroy the roof decking and rafters.

Rotten wood damage to decking and rafters on a flat roof in Andover, CT

We recommend that homeowners with a flat or low-slope roofs avoid the cheap alternatives which may last you 5 years, and will cost much more the next time you have to replace them, as additional repairs of rotten wood replacement and tear-off / disposal fees add on to the total price tag. Instead, choosing a lifetime IB roof system will make your roof last for decades of leaks free performance and will reduce your cooling costs, as its Cool Roof surface will reflect almost 90% of the solar heat. You will also be eligible to receive up-to $1500 tax credit for installing an Energy Star rated Cool Roof, making your final price almost the same as that of a cheap leaky alternative.

Benefits of installing an IB Roof are many, but here are some of them:

  • IB Roofing membrane is a fully watertight system, utilizing hot-air fusion welded seams, which insure a permanent bond between the sheets, flashing and even the drip edge.
  • There is no glues or adhesives involved in the installation, as is the case with EPDM rubber roofs. Rubber roofs use splice tape or black glue to keep the seams together, and after just a short period of time the adhesives break down, and the roof begins to leak.
  • IB Roof is a complete roofing system with all the components made out of PVC / CPA material, which are welded right to the membrane, ensuring permanent watertightness. There is a flashing for every possible roof penetration, such as in-roof drains, inside and outside corners, air vents, pipe boots, etc.


IB roof flashing accessories

  • IB Roofing membrane does not cure over time, and remains weldable even 25 years after installation. What does this mean for you? If there is ever any mechanical damage to the roof, such as falling tree branches or accidental cuts, the roof is easily fixed by just welding a patch to the damaged area. No need for special cleaners or glue. Just wipe the dust off and weld.

As an additional benefit to the environment and to your wallet, an IB roof will outlast 2, 3 or even more conventional roofs, which would otherwise have to be dumped in a landfill.

As a certified IB Roof Systems Installer, we can install and IB roof for you in any part of Massachusetts, Connecticut & Rhode Island, as well as in southern ME, NH and VT. Schedule your flat roofing inspection / estimate today.

Metal Roofing Installation – Our Unique Approach

It is no secret that a metal roof, although designed to last a lifetime, is only as good as its installers. Additionally, metal roofing is a completely different animal than asphalt shingle roofs, cedar shake or even slate roofing, and to be able to install a metal roof correctly, you need a professionally trained metal roof mechanic.

Usually when a metal roof is installed by a seasoned roofer, who never worked with at least one of many types of metal roofing, the results are more than sad. The roof begins to leak with the first rain, the roofer’s reputation suffers and a very unhappy customer seeks to resolve the problems with the manufacturer, and files complaints with BBB, Angie’s List and other consumer protection organizations. Fortunately, all of these troubles can be avoided if a professional metal roofer is hired to do the job.

We understand the needs of home and business owners, and their demand for the highest quality of materials and installation. We hand pick the best materials and the most thoroughly thought-out roofing systems, and combine them with our unique installation methods, which in the end, provide you with a true lifetime roofing solution, and unmatched beauty for your home.

Examples of our unique approach to installation of metal roofing:



In the above video clip, you can see how we approach the installation of this residential metal roof in Revere, MA. As with most roofs, attic ventilation is crucial to the longevity of the roof, its wooden substrate and the health of the entire home, including its occupants. There are multiple ways to ventilate the attic space, but the most effective way is to utilize a ridge and soffit ventilation system, where the cold air enters the attic through the soffit vents, located along the eaves of the roof and escapes through the ridge vent.

However, the ridge vent is often the path through which the wind driven water can penetrate the roof, causing slow, but devastating damages to the roof’s framing. Since the amount of water coming through the ridge vent is usually insignificant, homeowners will not notice the leak for many years, at which point the damage has already been done, and repairs can cost thousands of dollars. It is very common that the wooden substrate is completely rotten along the ridge line, and so are the tips of the rafters merging at the peak of the roof.

The solution to ridge vent leaks:

Water-tight ridge vent system

Water-tight ridge vent system

We designed a special way to raise the ridge vent off the roof level by 3/4 of an inch. While insignificant in terms of aesthetics, this bump-out prevents the wind driven water to enter the ridge vent cut-out, while the ventilation still works just as efficiently as it would have otherwise.

Notice, that the custom flashing we use rests on top of a pressure treated 1×4 board. The flashing is inserted into the top lock of the last course of aluminum shingles, which makes it impossible for wind driven water to penetrate the roof. Just as an extra protection measure, we use commercial grade exterior caulking at the joins of top locks between every shingle.

Flat Roof Installation in Andover, CT

I will describe the roof problems that our customer in Andover, CT had, and what we did to eliminate the roof leaks, as well as give him peace of mind that his IB Cool Roof will protect his home, and provide real money savings on the ever-rising energy costs.

On the roof in Andover, Connecticut - with a happy homeowner after the IB flat roof installation was complete
On the roof in Andover, Connecticut – with a happy homeowner after the IB flat roof installation was complete

Roofing problems and our roof installation in the words of the homeowner:

In December of 2008 my wife and I awoke to a dripping sound in our master bedroom. Much to our dismay the drip quickly became a steady stream of water, as we were experiencing a rain storm that totaled 4″. We placed buckets under the stream to mitigate the damages. The next morning I opened up the Sheetrock ceiling which was sagging down. Upon opening the ceiling I could see that all of the insulation and plywood was wet. As I moved across the room I found that it wasn’t just that area that was leaking, but several places. Our flat roof measures 20′ x 34′ and has a 1 pitch covered with 5 year old roll roofing. We tarped the roof and called a water damage restoration company to come in and dry us out. Unfortunately, MOLD was discovered growing on the underside of plywood decking, framing, and sheetrock. An industrial hygienist was hired to do testing and determine the mold spore levels. We ended up having to demolish the entire area and having the mold professionally re-mediated. The insurance company did not like to hear about mold. Their limit on coverage was $10,000.00 and we were facing $24,000.00 in damages!
This is a very small amount when you see how much it can cost to remove mold. Insurance companies also will not pay to repair your roof. Especially a flat one. They will only cover the resulting interior damage. I was frustrated with the extent of damages that occurred all from what appeared to be a little leak. Often times, by the time water comes through your sheetrock it is too late and you have lots of mold and wood damage waiting for you. After settling with the insurance company I began to research possible ideas to make sure this never happens again. I investigated the idea of raising the roof pitch, which proved to be very expensive. Next I looked into flat roof systems, such as rubber. I found that the seams end up leaking after a while. Not to mention the fact that it is ugly, and retains heat making the inside of your home hotter in the summer. I also looked into metal, but no one could install it on such a low pitch and guarantee me that it won’t leak. Finally, I found Leo’s website talking about the IB Roof system. I was amazed by the fact that this product provided a lifetime guarantee for the product and labor. I also loved the fact that it is attractive looking and reflects the hot sun keeping my home cooler in the summer. As an added bonus, in the future I can add IB solar panels to my IB Roof and generate my own electricity. I’m told that in some places the cost for IB Roof may be a bit more than the alternatives. However, for me the cost of the IB Roof was actually less than my quotes to go with a rubber roof. Therefore, it was a no brainier. Leo and his crew were on my job-site within just a few days after our initial contact. It was impressive to see how the construction was performed and you can really see the quality of the product. Leo and his crew were very respectful of our home and they kept the property clean. I have already recommended Leo and IB Roofing to a few people that I know have up coming flat roof projects. If you are considering a flat roof project you can’t go wrong with Leo and IB Roofing. Do it once, stay green, and enjoy!

Alex from Andover, CT

Roof problems, causes of leaks, and installation of a new IB Membrane.

When I first met with Alex, the roof had an expensive, heavy-duty tarp on it and about 5 inches of snow. Although it was the time of a very cold arctic air front in New England, it was actually good for Alex’s roof as cold temperatures kept the snow from melting for a couple of weeks.

Flat roof covered with tarp to prevent more leaks
Flat roof covered with tarp to prevent more leaks

Alex planned to tear-off the existing rolled asphalt roofing with the help of his friends over the weekend and, put the tarp back on, until we would come to install our roof. All went as planned, but it snowed the day after Alex and his friends removed the old roof, and replaced rotten plywood decking and fixed some rafters. On Monday morning snow melted and the roof began to leak again. The heavy-duty tarp turned out to be damaged in few spots, and the roof was virtually unprotected.

We had to adjust our work schedule to quickly come out and make Alex’s roof watertight, to prevent any more water damages and additional repair expenses. Fortunately, the weather was dry for a few days, and on Wednesday we came to install our roof. Once on the roof, we found that there were numerous causes of leaks. The major contributing factor was due to roof rafters caving in, and creating a cavity for water to puddle on the roof.

It is known among roofing professionals that standing water causes the majority of flat roof leaks. Standing / ponding water easily breaks the bond between roof laps, and enters the house, destroying insulation along the way. If left unattended, or unnoticed, these leaks will create thousands of dollars worth of damages, as well as pose a health risk – mold causes and/or aggravates allergies, asthma and other respiratory illnesses.

My evaluation is that most water damages occurred were water ponded on the roof. Other leaks occurred due to Ice Dams, where ice slowly “traveled” between the seams, and melted under the rolled asphalt, causing slow, but steady rot of plywood decking and mold. Although Alex’s roof is not completely flat, Ice dams are known to affect roofs that are completely non-walkable, so this very low pitch roof was an easy “prey”.

Roof Installation:

We use IB PVC roofs exclusively, because in my opinion it is not only the best flat roofing product on the US market, but it creates a completely watertight blanket over the entire roof. With IB, I can look customers straight into their eyes and honestly say: “Your roof will not leak!”

New IB flat roof.

A new IB flat roof

The reason why IB is such a great roofing system is the hot-air fusion welded seams. Once we weld two sheets of IB roofing membrane, a permanent bond is created, eliminating the possibility of water penetrations. Additionally, IB manufactures all the flashing components, which speeds up the installation process, and minimizes installation error.

Alex’s flat roof is actually an addition and was added as a shed dormer to a pitched roof. When this roof was constructed, builders put in a soffit / ridge ventilation system, which is always a good idea to have for wood roof frame / deck. However, a ridge vent can create many leaks problems, as it is very easy for water to be blown in by wind past the vent, and into the attic.

Normally, roofing contractors would just cover the ridge vent completely to eliminate leaks, but this would take away the ventilation, causing the plywood deck to dry out, de-laminate and slowly “dry-rot”.

We have created a custom design ridge vent assembly for low-slope roofs and shed dormers, where the vent sits two inches above roof level, eliminating the possibility of wind driven water entering the roof. Although the installation of such assembly is tedious and consumes a lot of time, it is the right was to go to maintain proper ventilation and to preserve the roof deck.

Ridge vent assembly for IB flat roof eliminates wind driven water leaks.

Ridge vent assembly for IB flat roof eliminates wind driven water leaks.

As you can see from the picture, the ridge vent sits on top of a 2×4 wood, which is completely wrapped with IB membrane to create a water-tight barrier, and prevent leaks through the ridge opening.

In Conclusion

Overall, it was a straight forward installation which took 2 days to complete.

Special thanks to Alex for providing us with delicious hot chocolate, which made our work easier and warmer during these cold January days.

If you have a flat roof in Connecticut, Massachusetts or Rhode Island, you can fill our roofing estimate request form. You can also get an instant price quote with our online Roofing Price Calculator.

Eco-friendly Cool Roofing

Cool Roofs provide financial and environmental benefits and long-lasting protection from the weather.

Roofing represents only 3% of construction costs. Yet, many builders, architects / specifiers, roofing contractors and even home / building owners look to reduce their total construction and/or renovation costs, and all too often they find these savings in roofing. This cost cutting comes not only at the expense of installation quality, but also with the use of inefficient roofing materials. Two most common roofing choices are asphalt shingles for pitched roofs and EPDM ‘rubber’ for flat roofs. The former is made directly from oil, and the latter is made with oil by-products and other chemicals.

Cool Roofing

Cool Roofing

Are Cool Roofs for everyone?

In theory, every roof should be cool. If that was the case, our nation would greatly decrease its energy dependence and consumption. We would also improve our environment and air quality, and use less electricity to cool our homes and buildings. Bear in mind that over 50% of our electricity comes from coal-burning power plants and coal is the dirtiest source of energy; it pollutes air with, sulfur, lead, arsenic, CO2 and other harmful substances and greenhouse gases.

However, many people would argue that cool roofs are only for Sun-belt states, and that black roofs are better for northern states. This is completely wrong. Lets review the differences of Cool (white) roofs and black roofs in terms of energy savings and heat gain in the summer vs. heat loss in the winter.

First of all, let me point out that in the winter, heat does not escape the building (unless you open your windows), but rather cold air enters the building and lowers the inside temperature. With this in mind, lets compare the energy cost advantage of a black roof in the winter and a white roof in the summer.

Energy Costs Calculation

Roof heat gait chart: IB vs black surface roofs

Heat gain through the roofing surface: As you can see from the chart above, on an 85 degree F day, an IB cool white roof will only gain 6 degrees or about 8%, whereas a black surface roof, such as EPDM rubber or rolled asphalt or a tar roof will gain 87 degrees (!) or more than double in temperature, for a total of 172 F. If you get down on your knees, you will actually get skin burns. Imagine all this heat entering inside your home or place of business…

For comparison purposes we will use a White IB PVC roof and a regular EPDM black rubber roof. We will use DOE Cool Roof Calculator and with following parameters:

Gas will be used as a source of heat, but since gas rates differ from city to city, we will convert the BTU value of 1 gallon of oil to that of 1 therm of natural gas. The oil price used in this comparison is $2.39 per gallon, which is the average here in Massachusetts for oil customers with delivery contract as of January 8, 2009. Please note that the price of 1 barrel of Oil today is $41.89.

Calculation metrics:

  • Insulation R-Value: 6, 13 and 20 (6 is the average for existing residential building where we replace a flat roof)
  • Solar Reflectance: 85 for IB Roof and 6 for Black EPDM. Although IB’s reflectance is 87% the calculator will not let us use more than 85, and since with dust accumulation on the roof reflectance drops, it is safe to use this number.
  • Infrared (thermal) Emittance: 88 for IB Roof and 86 for Black EPDM.

Scenario 1 – Boston, MA.

Cost of electricity in the Metro Boston area is approximately $0.22 per kWh. The cost of heating the building we get by multiplying price of 1 gallon of oil by 0.71  = price of “1 therm of heating oil” – $1.70 / therm. Note, that this is not the price of one therm of natural gas, but rather a BTU conversion from oil to natural gas. I use oil as it is the most common source of heat in the north east and in New England in particular.

Scenario 2 – Los Angeles, CA.

I will assume the energy price in CA, as I do not live there. For electricity rates I will use 30 cents per kWh. This assumes peak rate (when most people actually use their air-conditioners) and all the surcharges, delivery charges, etc. This is the total cost per kWh.

Since gas prices in CA right now are just a bit higher as compared to Mass. we will use $1.80 as the price of therm of heating oil. Bear in mind that in California, they rarely use heating and it is mostly natural gas or electricity or propane for remote homes.

Other calculation metrics:

  • AC efficiency: We use an average of 2.0
  • Heating System efficiency: We use an average of 0.7 or 70%. My brand new Burnham closed loop hot-water radiator system is 86% efficient. The older heating system it replaced was about 50% efficient if not less. Also note that this is the burner efficiency and not the total system efficiency. Total system efficiency is greatly dependent on how well your house is insulated, the type of windows you have and the type of heat delivery you use: radiant, air ducts, steam or copper pipes with hot water circulating through the system.

Results – Net Savings per 1 square foot of flat roof area per year: Boston:

  • With 6-r insulation Net saving is $0.079 or almost 8 cents.
  • With 13-r insulation Net saving is $0.037 or almost 4 cents.
  • With 20-r insulation Net saving is $0.023 or almost 2.5 cents.

Los Angeles:

  • With 6-r insulation Net saving is $0.217 or almost 22 cents.
  • With 13-r insulation Net saving is $0.1 or 10 cents.
  • With 20-r insulation Net saving is $0.062 or almost 6.5 cents.

Let us now assume that you home is 2000 sq. ft. and has 6-r insulation value of the roof. In Boston, MA you would save $160 per year in electricity alone if you replaced your existing black roof, such as epdm rubber or tar & gravel, with a cool IB roof. Also, add leak free performance of IB roofs, no more roof repairs and other costs associated with roof leaks. In Los Angeles, you would save $440 each year! Also add the Energy Star tax credit for cool roof installation of $500. This is an actual tax rebate, and it equals to an average of $1800 worth of tax deductions. Overall, I would say that Cool Roofs are much more efficient in the southern states where there is a lot more sunshine and almost no snow. But even here in New England, a cool roof is a very attractive choice for people who are looking to get long term savings, lifetime leak free performance and/or are worried about the environment.

Cool roofs vs. Black roofs

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While asphalt shingle is the ‘de-facto champion’ of sloped roofing with its VERY low cost and severe price competition in both residential and commercial markets, when it comes to flat roofing, there are more choices. Old-timers will recommend a 3 to 5 ply Built-Up roof or a two-ply Modified Bitumen. With the abundance of these and other tar and asphalt roofs still in service, and some new roofs being installed (although each year there are fewer BUR, asphalt and bitumen roofs being installed, as the flat roofing industry is quickly transitioning toward single-ply roofing membranes), all of these roofs are destined to end up in our land-fills, as recycling programs for asphalt-based roofs are virtually non-existent. That is millions of tons and billions of square feet of oil waste going into the ground each year!

Another problem associated with the above-mentioned roofing materials is their color – most are black, which attracts and transfers tremendous amounts of solar heat into the building or a house. As a result, the air-conditioning system must work over-time to maintain a comfortable working and living environment. This causes overloads and power outages on electrical grids, increased cost of electricity, and as a result – higher electric bills.

To offset the above-mentioned high cost of electricity, many people choose to install a Solar PV roof system. This is especially true in California where $0.35 – 0.40 per kWh of electricity is a normal residential rate. We wholeheartedly support nation-wide deployment of small and large scale solar photovoltaic systems, but the first step, which many people should take before installing solar systems, is to reduce their average energy consumption. This is where Cool Roofs come in very handy.

Financial Benefits of Cool Roofs

1 – Energy savings of Cool Roofs

Cool roofs provide tremendous reduction in cooling cost by reflecting 85-90% of solar heat and keeping your residence or place of work cooler in the summer. This directly reduces your electricity costs. This also puts less strain on your HVAC equipment, which leads to less maintenance, reduced repair costs and longer life for the Air Conditioning units.

2 – Cool Roofs last longer and leak less than black roofs.

Cool Roofs generally outlast their counterparts by 50-100% and require much less maintenance and repairs than Rubber roofs, modified bitumen and tar / asphalt roofing systems.

For a flat roofing market, the two major players are PVC and TPO membranes. These are single-ply, thermoplastic roofs which are hot-air welded together to provide decades of leaks-free services. There are also acrylic and urethane cool roof coatings, which make existing black roofs cooler and increase their service life by 5-15 years.

Note: PVC and American-made TPO roofs are fundamentally different in terms of their chemical formulation and life expectancy, but both are considered cool roofs and ideally should last 20+ years. Learn more about the difference between PVC and TPO roofing.

While 40 years ago there was no real alternative to asphalt-based roofing materials in the US market, for over 30 years we have had cool roofs that are energy efficient, light weight and provide long-lasting protection with much flexibility to accommodate for any obstacle present on the roof. PVC Roofs were the first real cool roofs to hit the US commercial roofing market. Some US manufacturers of early PVC membranes (most notoriously Trocal) had problems with their product, such as membrane shattering in extremely cold temperatures. The problem was due to the membrane being non-reinforced with nylon scrim. All major PVC (and TPO) membranes on the market today feature reinforcing scrim.

IB PVC / CPA roofing feature a true Non-wicking scrim, which prevents the capillary water penetration between the two layers of the membrane. This is only one of many benefits of IB PVC Roofing which sets it apart from all other flat roofing systems.

3 – Cool Metal Roofs.

Residential metal roofing

Residential metal roofing

For large commercial / industrial applications, there is structural metal roofing, usually found on space metal buildings, aluminum reflective coatings, etc. Although these do not meet Cool Roof requirements, they still are more energy efficient than black rubber and asphalt-based roofs.

For residential and some commercial / retail / restaurant applications there are various styles of Architectural Metal Roofing. Usually coated with Kynar / Hylar high-performance coatings (paint) these roofs carry a Cool roof label and also greatly increase the energy efficiency of your entire home or building.

Even without a Kynar coating, metal roofs are always “cooler” than asphalt shingles. Since metals (especially aluminum) have a much lower thermal mass, they do not store heat, and cool off much faster than any asphalt based roof.

Environmental benefits of Cool Roofs:

IB Roofs as well as other Cool Roofing systems provide enormous benefits to the environment. From reduced CO2 pollutions to reduction of roofing material waste going into our landfills, the whole chain of benefits is too complicated to fit into a general theme of this article. Therefore, I will only list the basic environmental benefits here.

General benefits to the environment: Again, I’ll use IB PVC roof as the example, but most other cool roofs will “fit the bill”.

As a side note, I’ll mention that USA makes up about 5% of world’s population, yet we consume 25% of the world’s energy. It is also estimated that 30% of US energy consumption is just wasted. Therefore, we (Americans) waste 7.5% of the worlds entire energy.  And we wonder why gasoline / oil / electricity is so expensive….

  • PVC roofs last an average of 2 times longer than other flat roofing systems. PVC is extremely durable & versatile – therefore rarely needs replacement. When you hear that PVC is not recycled bear in mind that most Pvc-based products are still in service.
  • PVC roofs are 99% recyclable and will find use in other applications after they complete their life-cycle. PVC rarely ends up in our landfills, as it is cheaper to recycle it than to dispose of it. You will usually see it at landfill sites as a waterproofing liner that will prevent toxins and pollutants from entering the ground under large piles of junk and waste.
  • Although PVC roofs use fossil fuel as one of its basic components (natural gas – methane, to be exact), they also use chlorine as the 2nd major component – therefore PVC contains 50 % less fossil fuels than other plastics (such as TPO roofs) and  do not use and carbon / oil-based products in it. Therefore PVC is not directly dependent on foreign oil supply, unlike Epdm / Modified Bitumen / Asphalt / Other Thermoplastics and oil-based products.
  • Cool roof properties of PVC (and other cool roofing systems) reduce electricity usage of many commercial / industrial / residential buildings year after year. As a result, less pollution is emitted into the atmosphere. In fact, if all roofs in the US were cool, we would reduce our nation’s energy use by an average 10%, which is now just wasted!