Flat roof materials

Spray Foam Roofing – Cost Effective and Eco-Friendly Flat Roof

Posted on September 16, 2010 by Leo - CoolFlatRoof

Whether you are considering getting a new roof for your home or business because you’re tired of patching leaks, or because you have heard how much you can save on energy bills with an eco-friendly roof, consider a spray foam roof.

What was that? Spray foam?

Spray foam roofing goes back more than 30 years, and its popularity has been growing exponentially because of its advantages over traditional roofing systems. What advantages, you ask? Consider this:

It’s monolithic, meaning it is one piece with no seams, which equates to no leaks
It insulates extremely well, and can lower the temperature of a roof by up to 100 degrees!
Long lifespan with periodic maintenance*
Pays for itself!

Spray Foam Roof Installation Process:

Installation is simple and relatively inexpensive! There are several reasons why this particular brand of roofing is so much less expensive than traditional methods. One of the main features of SPF is that the foam itself can adhere to nearly any kind of existing roofing material, with the exception of atactic polypropylene bitumen. This means that you don’t have to pay for the roofer to remove your current roof and pay landfill fees.

Usually, two 55 gallon drums, one with an isocyanate and the other with a resin, are hooked up to a machine that heats the liquids and combines them at the best ratio for effectiveness. Then the liquids are piped into a special spray gun that combines them upon application.

Once applied to the roof (after it has been cleaned to ensure the most adhesive strength), the combined liquids begin to form bubbles on a microscopic level, expanding to 20 or 30 times their original volume, all within about ten seconds, and you can walk on it in under a minute!

The final part of the installation is to apply a UV and weather protective coating to the foam. The type of coating really depends on your budget and how much energy you want to save, as well as how much additional durability you would like the roof to have. The color of the coating varies, but white is usually the best choice from an economical perspective. White will deflect the most sunlight, thereby reducing the amount of energy absorbed by the roof, and in the end lowering the cost for cooling the interior of the building.

Gravel and stretchy, elastomeric coatings are among the more popular options for protecting the foam roof. Other options include acrylic, silicone, butyl rubber and different types of urethane spray coatings. One more coat is applied on top of this spray coating, in order to help prevent physical damage from the elements, including ultraviolet sun rays. This final coat has gravel-like granules sprinkled on or embedded.

What’s in it for ME?

Well, for starters, you will begin seeing a dramatic decline in the cost of heating and cooling as soon as the roof is installed. Don’t believe me? What if I told you that when Texas A&M switched roofing systems in 1975 they switched to spray foam roofing. By making the switch to SPF, they saved so much money on energy savings that they were, on most occasions, able to pay off the construction costs within four and a half years, sometimes just two or three!

Durability and longevity are other major advantages for SPF roof systems. Excluding major weather incidents, there are usually no repairs or maintenance necessary for at least 10 to 15, maybe 20 years, depending on the type of system you have installed. When the time comes for maintenance, the existing roof will be cleaned and recoated, simple as that. A well-maintained roof can easily last 50 years or more. Talk about return on investment!

Cost of Spray Foam Roofing

Speaking of return on investment, how much will this investment set you back? Naturally it depends on a lot of variables including where you are, what kind of foam you prefer (as in density, thickness, etc.), what protective coatings are used, the building itself and the intricacy of the job. For average SPF systems you will probably be looking at starting prices of approximately $6 per square foot and up.

I hope this article has helped you in choosing a reliable, inexpensive and green roofing solution. All that’s left is choosing the right roof repair or replacement company for you. Overall, spray foam roofing is a great flat roofing choice. That, and enjoy saving up to 50% on energy bills for years to come!

This article was provided by Freedom Exteriors, LLC – premium roofing contractor in Arkansas. This article may not represent the opinion of CoolFlatRoof.com

Article commentary from from CoolFlatRoof Blog editor:

Spray for roofing is a highly energy efficient flat roofing material, which combines the roof insulation with the waterproofing layer. However, spray foam roofing or SPF, requires regular maintenance and complete re-coating every 10 years to maintain the protective layer over the foam. Without that protective layer, the UV rays of the sun will quickly destroy the SPF roof. It is best to coat the SPF roof with a urethane coating rather than with cheaper acrylic coating, and to add stone granules to the coating for longest performance.

One thing we want to mention is that SPF is a very popular flat roof material in the southern US, whereas up north, you will rarely see a spray foam roof (though I know of at least two large roofing contractors installing SPF roofs in the northern US with great success). Here in New England single ply membrane roofing is a more popular choice for a flat roof.

Another thing for you to consider is the situation with ponding water and how well the SPF roof will handle it. Rubber roofs for example will leak under ponding water, whereas a PVC roof with hot air welded seams will remain watertight. Although it’s best not to have ponding water at all, in many retrofit roof installations, you just can’t avoid it, so make sure that you get a ponding water guaranty from your reputable roofing contractor.

Flat Roof Installation

Posted on July 6, 2010March 13, 2016 by Leo - CoolFlatRoof

Flat roof installation sequence and the way different components are put together can oftentimes be quite confusing. We also get many questions about particular aspects of how roof details work in different situations. Our Roof Installation Guide will answer these questions and demonstrate the step by step process of installing an IB PVC flat roofing system. We welcome any questions you may have – you can ask them in the comments section at the end of this article.

IB PVC Flat Roof in Massachusetts

Average 1500 s.f. Roof Prices in US

Asphalt Shingles $5718	Flat Roof $9869	Metal Roof $14711
See costs in your area Start Here - Enter Your Zip Code

Installing a flat roof (PVC single ply roofing membrane in this case) can be a pretty straight forward process, or a very confusing endeavor, because each component must be installed in a particular order. Otherwise the system may not work the way it should. Of course there is an installation spec manual from IB roofs, which we always keep handy, and actually had to use once or twice. However, this manual only shows particular flashing detail or a general way of how the membrane and insulation ought to be installed. It can’t possibly cover all the specifics of the roof installation that come up in the field.

Flat roof installation – prep work – insulation, wood nailer and penetration flashing

Lets start looking at the prep work, and the order in which things actually happen:

PVC Roofing is a very durable and long lasting flat roofing material. However it should never be in direct contact with any oil and asphalt (also oil) products. Since most other roofing materials are made with oil or asphalt, we always install a protection layer between PVC membrane and either old roof or the roof deck. We usually use insulation to protect the membrane from being in contact with asphalt and also from deck fastener punctures. Roof insulation also serves its primary purpose of improving thermal insulation properties of your roof.

Before we install insulation though, we first install a perimeter wood nailer that serves as a rigid nailing base for the PVC-coated drip edge. Once wood nailer is in place, we lay out the insulation sheets and fasten them to the roof deck, using FM Global 60 or 90 mph wind rating standard – 8 or 10 plates + fasteners per 8×4 feet insulation board (although this is unnecessary, since it is a mechanically attached system). Once the wood nailer and insulation are in place, we install one or more rows of perimeter half sheet, which is a 3 foot wide roll of membrane, vs a standard 6 feet width for field rolls. The perimeter half sheet is installed to prevent wind uplift, and is fastened either 12″ o.c. or 6′ o.c. (for high wind areas).

Flat roofing – tapered insulation

Average 1500 s.f. Roof Prices in US

Asphalt Shingles $5718	Flat Roof $9869	Metal Roof $14711
See costs in your area Start Here - Enter Your Zip Code

If there is a ponding water situation, the fastest and most cost-effective way to solve the ponding is to install a so called tapered insulation system, which creates slight roof pitch, which helps divert the water in a required direction and improves roof drainage.

Tapered insulation is basically the same thing as extruded PolyISO insulation with a fiberglass facing. The only difference is that tapered insulation is wider along one edge and narrower along the other. A tapered insulation system can have a roof slope ranging from 1/8″ per one foot run, to 1/2″ rise per one foot run or more.

Flat roof installation – mechanically attached assembly

A reinforced PVC single ply roof allows installers a choice of installing the roof in a fully adhered assembly (sheets of membrane glued to the insulation) or a mechanically attached assembly, where each sheet or roll of the roofing material is screwed to the roof deck substrate with heavy duty, corrosion resistant fasteners, and barbed plates. Each roll is screwed to the roof deck on one side, and then the next roll, overlaps a row of screws, and is welded to the first roof, right next to the screws. Then the process continues in the same manner, until the whole roof is covered by the membrane.

As you can see in the roof installation picture above, the narrow roll of membrane is installed around the roof perimeter and wider rolls are in place, and are ready to be installed. However, before you get to this point, there is a lot of prep work that has to be done first, and the actual membrane installation is the easy part.

Normally, we use a 1/4″ tapered insulation system which raises roof level 1″ for every 4×4′ insulation piece.

Drip edge detail

As we mentioned the perimeter half sheet is installed along roof edges, and fastened on the inside with screws and plates – what is holding the half sheet along its outer edge? Well, this is the question that homeowners often ask me. The way IB PVC roof system is designed, allows us to attach the outer edge either directly to the drip edge or run in over the roof edge by a couple of inches, nail it to the fascia board and install a drip edge metal over the membrane.

Both ways are acceptable, but most of the time we use the second method – especially in high winds area. Once the roofing material is installed and flipped down, over the edge of the roof, we install 10 foot sections of 22 ga PVC coated galvanized or stainless steel drip edge, and fasten it to the deck with the roofing screws, either 12″ or 6″ o.c. Then we weld a 5″ wide cover strip of the membrane to the roof and to the drip edge, to seal the screw holes and bake the whole detail water-tight.

Check out our video on how drip-edge metal is installed:

Once the 10-foot sections of drip-edge are installed, the joins are sealed using an aluminum tape and a PVC patch to mack the joint water-tight and protect the patch from metal expansion and contraction. After the joints are complete, the cover tape is welded to drip edge starter and the roof itself, and its now time to do the rest of the roof.

As a side note, there are many options for drip edge detail. Although the most used drip edge is the 2 or 3″ wide face, white starter, you can also choose it to be as much as 8 or more inches wide, as well as in gravel stop style (if you need to divert the water flow or prevent it from going over the edge of the roof.

Gravel stop drip edge has a 1″ bump-out, which stops water from spilling over, and makes it run down the roof – toward a drain or a gutter. Drip edge comes in two colors – white and dark bronze, and also can be painted any other color with acrylic paint. IB roofs also offers 16 oz. copper drip edge, with PVC material adhered to the flange, and can produce any style drip edge, with different angles, kick-in or kick-out face and in various widths.

Flat roof installation – field sheets, roof penetrations and roof to wall termination:

After all edge detail is complete, we install the field rolls of membrane and all penetration flashings, such as pipes, drains, HVAC / Skylight curbs, roof hatches, chimneys, etc.

IB Roof Systems produces a wide variety of flashing accessories, which allow installers to quickly and easily flash almost any roof penetration. Since all roof components are made of PVC, they are all welded together, and the use of any adhesives or glues is completely eliminated, as well as most installation errors by roof mechanics.

All curb and up-the wall flashing is installed using a two-step process. First, the roof is terminated that the wall, and then a separate piece of membrane is installed up the wall and welded to the roof.

After the flashing is installed and welded to the roof, the inside or outside corner flashing is welded to make a permanent watertight joint.

All IB flashing accessories are made of 60-mil non-reinforced flashing membrane and can stretch to perfectly adhere to any shape of a penetration on the roof. Pipe flashings and drains have a reinforced flange to be welded to the roof.

Bellow is a video demonstrating the curb flashing installation around a skylight:

As you can see in the video, the roof penetration flashing is a very clean process, and a chance of a leak is minimal to none. Unlike flashing details on a rubber roof, where a membrane cannot and should not be terminated at the base of the curb, due to high possibility of a leak caused by adhesive failure, the hot air welding process used in sealing overlaps and seams on a PVC roof, eliminates leaks, as well as membrane pull-out caused by contraction of the roofing material in cold weather.

Special flashing details

IB roof spec manual does not cover all installation details, as in the real world you often run into situations where you have to “improvise”, while your roof must still be watertight. One such example is the ridge vent detail on flat / low slope roofs such as shed dormers. While many low slope roofs are considered “flat”, they were built as sloped roofs with ridge / soffit ventilation in mind. However, many roofing contractors that install EPDM rubber roofs, block the ridge vent opening completely to prevent roof leaks.

We’ve developed a special assembly method, which allows us to still use the ridge vent, and keep the roof watertight. We run our roof up-to the ridge opening, weld additional strip of membrane, install a 2×4 wood to raise the level off the roof, flip the strip of membrane back and wrap the 2×4 with it. This prevents wind driven water from penetrating the roof, and ridge vent + ridge cap is installed on top, 2 inches up.

As you can see, IB PVC roof can be adjusted to virtually any type of flat roof, and roof penetrations. We recommend that you check out more roof installation videos on our Roofing Videos channel on YouTube.

You can see more examples of flat roof installations that we have done all over New England: Roofing in Massachusetts and roofs in Connecticut. We provide residential roofing and commercial roof installation services in all New England states. However most of our work takes place in MA, CT and RI.

Also, if you have a flat roof deck that is leaking, check out our roof deck section, to learn more about IB roof installation on flat roof decks, patios and balconies, using special slip-proof roofing material called IB DeckShield.

Residential Flat Roofing – Forget About Your Roof Leaking With IB Roofs

Posted on June 23, 2009 by Leo - CoolFlatRoof

Does your low-slope roof leak due to Ice Dams problems? Does your ridge vent leak, or did you have to completely remove the ridge vent to stop leaks? Poor ventilation and attic insulation is causing your ice dams, but now you can solve this problem efficiently and economically.

An IB PVC Membrane is a solution that will keep your home, probably your biggest investment, watertight and ice dams free for decades to come!

Residential IB Cool Roof in Wallingford, Connecticut. This 80-mil grey roof perfectly blends with the house, keeps the water out, and homeowners happy. No more patching or repairs, no more worries!

Ice Dam leaks and Poor Ventilation

Most low sloped roofs in the northern United States have Ice Dams, which cause roof leaks and expensive roof repairs as well as cosmetic interior repairs of ceilings, walls, carpets and wooden floors. Those are the damages that you can actually see.

Ice dams also create invisible structural damages, which you can’t find until you open up ceilings and walls. These damages are extremely expensive to repair, as it would require hiring interior remodelers to fix structural damages, outside and inside walls, electrical systems, plumbing, etc.

Ice Dams in a Nutshell

Ice dams are caused by poor attic ventilation and heat loss from the inside of your living space. Large piles of snow will accumulate on your roof after a snow storm. If your attic is improperly insulated and ventilated, the warm air escaping from your living area into the attic, will melt the snow. The water from melting snow will run down the roof and refreeze, usually along the eaves of your roof. These are Ice Dams. The more snow is melting the bigger Ice Dams you have. After some time, the ice dams become so big, that the melting water cannot travel downward anymore, so it starts to travel upward underneath the roof shingles or rolled roofing seams. As it freezes under the roof, warm air melts it, and it slowly starts to drip inside the attic, causing all of the above and below mentioned problems.

It becomes a vicious cycle were more heat loss creates more ice dams, which cause more damages to structural walls and insulation, destroying your home from the inside, increasing your energy-related expenses, and causing more heat loss, which creates bigger ice dams…

One negative effect caused by ice dams, and which many homeowners neglect to address is the wet insulation in the attic and inside walls. When insulation gets wet, you loose insulating value, so your energy costs increase, as heat loss in the winter drives up your heating bill. The same happens in the summer with cooling. Also, mold begins to grow in the attic and inside walls, which cause and/or aggravates allergies, asthma and other respiratory illnesses.

IB Membrane Solves Ice Dams Problems

An IB membrane is a perfect way to eliminate Ice Dams on a low slope roof, as it is a seamless blanket over the entire roof. Hot air welded seams prevent water from backing up and re-freezing, as is the case with shingles and rolled asphalt roofing, therefore eliminating the effects of Ice Dams. Also, most of the snow will actually slide off the IB roof, thus there will be a minimal Ice and Snow accumulation along the eaves.

Additionally, we’ve designed a special Ridge Vent system, which we use on every low-sloped roof with ridge/soffit ventilation in place. This system prevents the wind driven water from entering your attic space through the holes in the ridge vent, while allowing the warm air to escape the attic. Check out our special Low-Slope roof ridge vent assembly, which improves your attic ventilation and eliminates leaks!

Ridge ventilation system for low sloped roofs

Rubber Roofing (EPDM) – Pros and Cons of Using Rubber Flat Roofs

Posted on June 15, 2009April 21, 2020 by Leo - CoolFlatRoof

Rubber roofing (EPDM single ply membranes) is the most common flat roofing system in New England (MA, CT, NH, RI, etc.) and the rest of US flat roofing marker. Most people refer to a flat roof as a “rubber roof”.

The main reason for such popularity of rubber roofs is the lower initial price tag. However, rubber roofs have many inherent problems.

These problems cannot be solved by technology, because of their design, as well as issues with unprofessional contractors claiming to be “rubber roofing pros“.

However, you can do the repair yourself, saving hundreds of dollars, and avoiding shady, unqualified contractors. Here is how to do it:

You can source the materials and tools from local suppliers (you will have to buy in bulk though, and have tons of extra material), or use a DIY Rubber Roof Repair Kit, specially designed for DIY homeowners, small businesses, maintenance personal, etc.

What You Need to Know About Rubber Roofing

Homeowners with flat roof homes often find themselves in a situation where their roof starts to leak rather unexpectedly – i.e. only after a few years since it was installed.

This for the most part happens to homes that have a rubber roof on them. While most flat roofs will only last 10-15 years, older systems such as Tar & Gravel, BUR (built-up) and in some cases Modified bitumen roofs.

These roof types are usually installed by roofing contractors that are somewhat specialized in their field of work – these are “the old-timers”, or former union guys that decided to try their luck working for themselves, and they actually went through special training and have years of experience.

Incorrectly installed EPDM roof in Quincy, MA – rubber glued right over shingles:

The problem is that roofing systems they install do not last long for many reasons outside the scope of this article. By contrast, most rubber roofs are installed and repaired by roofers that have no special knowledge or training, they take on EPDM roofing jobs, because they are seemingly easy, inexpensive to install and require no special expensive equipment.

If you have a leaking rubber roof in Massachusetts, Connecticut or Rhode Island we can give you a roofing price quote to replace your roof with our flat roofing material of choice – a new, lifetime PVC Flat roof manufactured by IB Roof Systems. We can also repair your rubber roof at a relatively low cost, using only the best materials that rubber systems have, and extend the life of your roof by a few years. One example of such materials are peel-and-stick flashing and seam tapes. We do not use black rubber glue as it is outdated, and leaks much faster.

BAD Rubber Roofing Video – this is why you don’t want to have a flat rubber roof:

Why Are Rubber Roofs So Popular?

Rubber roofs (EPDM) are the most used flat roofing products in the US / Canadian commercial roofing market. They we first put in service over 40 years ago, and since gained popularity among roofing contractors and their customers. The reason for such success lies in the condition of the flat roofing market at that time and the available alternatives.

Back in 1960’s oil was still very cheap, it was more than a decade before the oil crisis of the 70’s and there wasn’t that much demand for oil. The oil refining process was far from being efficient and the industry was looking to get rid of many by-products of the oil refining process.

At the same time, the flat roofing industry was the same as at the turn of the 19th century, and the most common product to use on a flat roof was either a BUR (built-up roofing, using multiple layers of tar paper, saturated in hot tar or hot asphalt) or Tar & Gravel roofing, which was essentially a BUR roof with gravel added for additional protection. Flat roofing technology has not changed for 100 years and contractors needed a new, easier to install and cleaner product, hence, EPDM rubber roofing system was born.

EPDM consists mainly of oil based by-products with some modifiers and stabilizers added to extend its service life. Rubber roofing was cheap to produce, easier to install than conventional (BUR) roofs, did not require any special equipment to put it down and the membrane could potentially last for decades, as it was UV stable and did not break down when exposed to the weather.

Because rubber roofing was cheap, quick to install, and offered a potentially long service life, and with lack of any opposition from better roofing products, it quickly became the king of flat roofing and the pioneer of the single-ply flat roofing market.

Useful resources:

DIY epdm rubber roof repair – Our original article on how to fix a rubber roof with EPDM rubber adhesive (no peel-n-stick tapes)
Rubber roof repair guide – A part 2 of our Do-it-yourself guide teaching you how to fix EPDM rubber roofing systems with primer and seam tape.

PART 2: Avoid using “roofing pros” who do not specialize in flat roofs:

Below we will explain that one of the major problems with rubber roofs is the poor workmanship of roofing contractors who install and repair them. We will demonstrate how many roofers are “trained” in installation of EPDM single ply roofing systems, as well as results of their work (our Horrible Rubber Roofs series).

The Truth About Residential Flat Roofing Market and Contractors

Rubber Roof Contractors: It is unfortunate, but most residential flat roofs are installed by roofing contractors that specialize in asphalt shingles. Since they can easily purchase rubber roofing materials from their roofing supply warehouse, and are not required to be certified installers, nor do they need any special training or equipment, they will often undertake such projects to keep their crews busy.

Horrible Rubber Roofs Videos:

Horrible rubber roof part 1.
Location: Brockton, MA
Date taken: Summer, 2011

Horrible rubber roof part 2.
Location: Revere, MA
Date taken: Fall 2011

Horrible rubber roof part 3.
Location: Country Club in Central MA
Date taken: Summer / Fall 2011

These are just some roof inspections that we did in the summer / fall of 2011. Look – even commercial roofs are not immune to hack roofers and faulty materials (like rubber roofing), but in residential, this is much more common.

Contractors’ Lack of Knowledge and Lack of Training

To get a quality rubber roof installed, it usually has to be done by a commercial roofing company that specializes in flat roofing. However, it is often the policy of such companies not to work with residential customers, for which there are many reasons. These contractors work with large commercial and institutional customers, employ union workers who are trained roof mechanics, specializing in their particular niche. For example, a commercial roofing contractor will have separate crews doing metal roofing or slate – these guys are “roofers”, and yet another crew doing flat roofing ONLY – these are “roof mechanics”.

A residential roofing contractor usually employs just roofers, who are good at what they do all day long – install asphalt shingle roofs, and often do not have a clue about how flat roofs work. When they get a potential client with a flat roof, they go to their supplier, ask what supplier has for flat roof, and the salesman at the supply warehouse TEACHES the roofer how to install EPDM rubber. This is not creative fiction or a product of my imagination – I see this happening nearly every time, when I come in to the supply store to get something.

“Trained rubber roofing installers”: If you are lucky, you may get a roofer that has received some sort of training about rubber roof installation. For example, one of my suppliers, provides installation training programs for their roofing contractors who install only asphalt shingles. The idea behind such training seminars is to increase awareness and solicit sales of more roofing products. A manufacturer technician provides a sample installation on a 8×8 feet demo stand.

Below is an example of such “hands-on rubber roofing training”.

epdm rubber roof installation

As you can see, the roofers just sit around the demo stand while the MFG Installation technician shows them what to do. The whole demonstration took about an hour and a half, and covered thing like installing flat roofing insulation (ISO), adhering rubber to the ISO board, flashing a sky-light / chimney penetration with un-cured flashing material, installing the membrane up the vertical wall, cleaning & priming seams and installing seam tape, installing drip edge and a tape to seal the drip edge fasteners, and installing termination bar. In the same 1.5 hours we’ve also “learned” how to correctly apply yellow glue – membrane adhesive, seam primer – seam & flashing glue and how to install these systems in the winter, while violating manufacturer’s installation specs.

rubber roofing

Out of 25 or so roofing contractors present, there were about 15 or so questions particular to the installation details. 7 of them were asked by me! Bear in mind that I already knew how to install a rubber roof and attended the event to talk to my salesman, representatives of the metal roofing manufacturer and for free refreshments 🙂

In any case, each one of those 25 or so roofing contractors, willing to learn a new, and very complicated roofing system, asked an average of 0.3 questions about this system.

Rubber Roofs for Residential Customers: It was clear that my supplier and the roofing representatives were selling to Residential Roofing Contractors. Not once did they mention roof-top HVAC units, roof hatches, elevator shafts, gas/electrical pipes, roof drains, etc. They did however insist that the rubber is a good choice for a low slope shed dormer (without mentioning the poor low slope roof ventilation and ice dam prevention associated with shed dormers). They also mentioned that rubber is a good choice for a flat roof decks and patios.

Single-Ply Flat Roofing Membranes – PVC, TPO & EPDM Rubber Roofs

Posted on June 15, 2009 by Leo - CoolFlatRoof

In our overview of Flat Roofing Technologies: Part I – BUR, Tar & Gravel and Modified Bitumen, we discussed the older and in many ways inefficient types of flat roofs, that are not only outdated by today’s standards, but also have a short life cycle expectancy. Moreover, they pose numerous obstacles when it comes to repair, as discussed in our Flat Roof Repair guide.

In Part II, we will take a look at the newer, more advanced roofing technologies, and explore the advantages and disadvantages of each single-ply roofing technology commonly used today.

What is single-ply flat roofing?

There is a lot of confusion about single ply membrane roofing. Many people think that any ‘single ply’ is the answer to their flat roofing problems. This however is far from being the truth. In reality, single-ply roofing membranes have only one thing in common – that is: they are single ply, or just one layer of membrane that is a waterproofing barrier. The similarity stops there.

IB Flat Roof installation in Weston, MA

Membrane formulation, or the components a membrane is made of, marks the biggest difference between different single-ply products. Single ply membranes come in various widths, ranging from 6 to over 18 feet. In theory, the wider the membrane is, the less overlapping seam you have, thus reducing the possibility of leaks. The reality is different however, and most commonly used membranes do not exceed 10 feet in width.

The most crucial aspect to the reliability and longevity of single ply roofs is the method of attaching overlapping seams together. That is where 99% of flat roof leaks occur. Therefore, having permanently attached seams is the most important factor in the longevity of a flat roof installation. We will discuss it in more detail as we review different single ply roofing technologies.

Single-ply Membrane Installation Methods

Single ply membranes are installed either as fully adhered or mechanically attached systems, depending on each roof’s condition, installer’s preferences, and other factors. Underneath the membrane, there is usually a separation barrier and/or some sort of insulation board. Most common insulation is ISO or EPS foam board. Both types have an R-value ranging from 4-R to 6-R per 1 inch of insulation thickness.

Mechanically attached IB CPA/PVC Membrane on a roof of residential house in Providence, RI.

Mechanically attached IB roof with hot-air welded seams, ensures that your roof will be leak free for many years to come, and high wind uplift will not cause damage to your building. Mechanically attached installation uses heavy duty screws and barbed plates to hold the membrane down tightly, and is not affected by possible ISO de-lamination. The membrane is attached using 12″ O.C. pattern with perimeter sheets attached 6″ O.C. This ensures that even the hurricane-type wind will not tear off your roof. Mechanically attached installation method does not require the use of heavy and expensive ballast, and is a preferred choice, if your building is located in a high-wind area, such as along the coast line or on a high hill.

Fully adhered single ply membranes are glued to the fiberglass sheet, laminated to both sides of the ISO insulation, which is in turn attached to the roof deck. While quick and simple, the fully adhered method has one serious disadvantage. If condensation forms underneath a roofing membrane, which often happens and may be caused by improper ventilation of the roof deck, it will ‘de-laminate’ the ISO board and/or adhesive that is holding membrane in place. If the membrane becomes loose, it is prone to wind blow-off, which will leave your roof unprotected. Results of such blow-off will be catastrophic not only to your roof, but to the entire building. While this is rarely the case, it is still a possibility – a gamble you might not want to take.

More common problems with fully-adhered single-ply flat roofing systems (Mostly EPDM rubber) are defects in glue/adhesive application that cause bubbles, badly glued seams and as a result, a very unpleasant view and more often then not, roof leaks. The image bellow demonstrates a defective EPDM rubber application.

Find out more information on why you should avoid installing EPDM rubber roofing on you home and how residential roofing contractors are trained to install rubber roofs.

Three most common single-ply roofing systems

Today, when it comes to flat roof replacement, single ply roofing is the top choice. More and more contractors are switching from old systems, such as BUR, Asphalt, and Tar & Gravel to single-ply membranes, which are easier, safer and faster to install. Single ply roofing installation does not require torching, used in Modified Bitumen installation, and therefore there is no fire hazard/possibility to burn down your home / business.

There are 3 most-used single ply membrane systems present on the market today: PVC/CPA, EPDM rubber and TPO. Bellow, we provide a brief summary of each of these systems.

PVC (CPA) Roofing

PVC – Polyvinyl Chloride – a thermoplastic membrane, utilizing a reinforcement scrim between the two plies of equal thickness (IB roof only). Top ply contains Cool Roof pigments, UV stabilizers, and other components to extend the life of the membrane. Bottom ply contains PVC ingredients to provide consistent weld of top and bottom plies and fillers. Material Warranty Period: Up to 25 years Commercial / Lifetime Residential. PVC life expectancy: 30+ years. The reason for PVC’s superior durability and longevity are the seams, which are hot air welded and as a result will be impervious to leaks and will never come apart.
Special Notes: For a complete overview of IB flat roofing products for residential, commercial and restaurant use, as well as installation method and roofing accessories refer to our IB Roof products page.

Learn more about IB’s outstanding single ply flat roofing membrane, its advantages, and many choices for Residential, Commercial and Restaurant use.

TPO Roofing

TPO – Thermo Plastic Olefin – a thermoplastic membrane utilizing a reinforcement scrim between the two plies. 35/65 % thickness for top & bottom ply respectively. Top ply contains Cool Roof pigments, UV stabilizers, and other components to extend the life of the membrane. Bottom ply contains TPO ingredients to provide consistent weld of top and bottom plies and fillers. Note that the top ply is about half the thickness of the bottom ply. Yet, the top ply is the one that makes the roof long-lasting. IB PVC has a 50/50 or equal thickness of top/bottom ply.
Material Warranty Period: Up to 20 years Commercial / None for Residential. TPO roof system life expectancy – 7 to 20* years. Like PVC roofs, TPO systems also use the hot air welded seams technology to make the roof durable and leak free. However, problems with the membrane formulation, are a source of many issues. You should know that there is not a single TPO installation in existence in the USA, that was produced in North America and is older than about 15 years. Therefore it is unknown how long a TPO system will perform without any leaks*.
Special Notes: * TPO roof systems are under continuous development by numerous manufacturers, who constantly change the TPO formulation to achieve the lowest cost with acceptable performance. While it is understandable that businesses always look to save money and to reduce costs, this ongoing TPO development process is being conducted, often at the expense of the roof owner. A TPO roof from the same manufacturer will most likely NOT be the same as the one produced a few years before or after. Also, the quality of different batches of TPO membranes may be questionable, as some TPO producers release the product to the end user without getting the UL and similar approvals/certification, as the formulation changes too often. Refer to our comparison article of PVC vs. TPO to find out more about the TPO problems / short-comings.

EPDM Rubber

EPDM Rubber – Ethylene Propylene Diene Monomer – a rubber-like black membrane, usually non-reinforced. Most common application method is a fully adhered (glued down) membrane with glued seams / flashings.
Material Warranty Period: Up to 40 years Commercial / None Residential. EPDM roof system life expectancy – 10 to 15 years. Although the material warranty goes up to 40 years for a 90-mil Epdm from some manufacturers, it does not cover the seams. Failing seams are the main cause of EPDM roof leaks, followed by ponding water, for which EPDM has no warranty either.
Special Notes: EPDM is the least expensive single ply roofing type and requires no special equipment to install it (unlike PVC and TPO which require hot-air welding equipment) and thus is the first choice for contractors entering the flat roofing market and asphalt shingle roofers, who ‘install rubber here and there’. Although many commercial roofing companies also use EPDM, they usually do not perform Residential installations so many times a home owner deals with a Part-Time flat roofing company.

Badly installed Rubber Roof:

EPDM roof bubbles - what happens when a wrong adhesive is combined with wrong roofing membrane and a wrong installation method.
Please note that there are many manufacturers of all three types of roofing, and each has their own formulation / manufacturing process / warranty conditions and periods, etc. Therefore we only provide a general summary for each of those roof types. Also, since our specialty is installation of IB roofs, when we use the term PVC or CPA we refer to IB PVC Roofs (CPA or Co-Polymer Alloy is the way IB Roof Systems refers to its PVC product. IB membranes are 100% ‘compatible’ with other PVC products).

Flat Roofing Materials – EPDM rubber, BUR, Tar & Gravel & Modified Bitumen

Posted on June 15, 2009June 17, 2016 by Leo - CoolFlatRoof

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Flat Roofing systems: The purpose of a flat roof or any roof for that matter is to keep your home or building safe and dry. The roof MUST protect your investment from the elements such as rain, snow, and even the sun’s heat.

However, many flat roofing technologies on the market today have some major, inherent drawbacks that have origins in their design. In fact, most flat roofs fail to serve their main purpose just a few years after they are installed.

You are presented with so many choices for a flat roof and every roofing contractor will tell you their product is the best.

But which one do you choose and how do you know that you are getting the best deal? Here we have summarized the most common and ‘popular’ flat roofing choices. You can be the judge and decide which is best for you.

Benefits of flat roof construction:

There is a common misconception among many home-improvement contractors and residential builders / architects that flat roofs = problems.

The truth is that flat roofs are very convenient, easier to build, and cost less than pitched / sloped roofs. In some cases, a flat roof is the only way to go, for example, when you have a large size building.

Building a reliable pitched roof in those cases will require extra engineering to accommodate for additional structural weight.

IB roof replaces two sections of this textile factory roof located in Central Falls, RI. These two sections had the most leaks, which were damaging expensive machinery.

Flat roofs are also convenient for installing large HVAC equipment that otherwise would have to be installed on the ground. You can also use flat roof as a roof-top deck, patio or penthouse. Green roofs are also gaining popularity with environmentally conscious companies and organizations.

When you compare all the construction costs and environmental benefits, flat roofs by far surpass any sloped roof, for which the roof products of choice are oil-based asphalt shingles. These asphalt shingles end up in our landfills every 12-15 years, and yet more and more of them are produced.

Limitations and Disadvantages of flat roofing:

Flat roofs also have a number of disadvantages. The main one is the fact that there is no slope and all the water/snow sits on the roof. While water can be taken care of with proper drainage, snow will sit on the roof until it melts. This requires the engineers / architects to implement building components with a higher structural load. Another disadvantage that haunted flat roof installations for over a century is ponding water. Until the invention of single ply membranes such as an IB roof, there was no effective and economical way to eliminate the leaks caused by ponding water. That had to be taken care of in the initial design/construction stage. Creating a slight pitch and multiple drains was required, and still ponding water caused over 75% of all flat roof leaks.

Now the ponding water problem is solved by either implementing a slight pitch to the roof – such as in ‘space metal buildings”, using tapered insulation to direct water flow toward drains and with the creation of IB PVC / CPA roofing with hot-air welded seams, ponding water is no longer a problem in small quantities. It is still necessary to have adequate drainage system, since a lot of ponding water can cause structural damages to your house or building.

Types of flat roof: Modern and Outdated roofing technologies.

Outdated (Multiple-Ply Roofs) – some are over 100 years old:

Build-Up Roof (BUR)
Tar & Gravel
Bitumen (Modified Bitumen)
Rolled Asphalt (usually a “single-ply” install, sometimes uses tar-paper as base ply)

Modern (Single-Ply Membranes)- created within last 30 years:

IB Roof (PVC roofing) – IB PVC roofing membrane is one of the best low-slope and completely flat roofing products available, and that is precisely the reason why we only install IB roofs. With over 30 years of spotless reputation and leaks-free performance in many different climates – from Alaska’s frigid north-lands to Hawaii’s tropical paradise, IB roofs are protecting the buildings and everything inside, without a single material failure since 1978.

IB roofs still feature the same chemical formula as its original design, and with hot-air welded seams, will maintain complete water-tightness over your roof.

Epdm Rubber Roof – a widely used flat roofing material, mainly popular among contractors because of its low price and no special equipment needed to install the rubber roof. Still, rubber roofs are very prone to leaks, as the seams are glued together, and adhesive tends to break down within 5-7 years. Also in the residential roofing market (and not so much in commercial) there are too many contractors who will install rubber roofing products without proper knowledge and training. As a result, we often go to rubber roof repair service calls to fix problems caused by poor workmanship, often on fairly new roofs.

TPO Roofing – a single ply thermoplastic roofing membrane similar to PVC roofs from a first glance. But as you start digging, you’ll find numerous problems with TPO roofs, mainly as a result of manufacturers skipping on adding important ingredients into formulation of the TPO membrane, and as a result, quietly scrapping as many as three major generations of the product.
SFR – Sprayed Foam Roofing (not a single-ply)

Part I: Inferior and outdated flat roofing technologies

These are very common on older buildings, although many newer buildings also have these systems installed. They are rarely installed on any commercial building today. However, they continue to be produced, and many roofers still install them on residential and small commercial roofs. This is particularly due to their low cost of material, and roofers’ lack of experience with BETTER solutions. It is sad that there are some decent roofers offering such an inferior product to their customers. I often hear something along the lines of: “I’ve been doing ‘torch-down’ for 20 years, and it is the best” – very sad – so we will briefly describe them, without getting into details.

BUR / Tar & Gravel / Torch-down: Multiple-ply roof where each ‘tar-soaked’ ply is applied with a torch (yes, open flame on your roof!), or hot mopped (preheated tar transported to the roof and applied with a mop). Gravel goes on top of this ‘sandwich’ mainly as a protection layer from foot-traffic and sun’s devastating ultraviolet rays. There are many deviations from the above procedure, but they are all within a close range of similarity.

Two layers of Tar & Gravel fail to keep this roof watertight

Modified Bitumen: It is also applied with a torch in a similar manner described above. It is however a different material than tar. Modified bitumen has rubber and elastomers added into the formula, so it is stronger and more flexible.

Rolled Asphalt: Similar to asphalt shingles – tar paper is saturated in asphalt, with crushed stones glued on top of it. Rolls are installed in an overlapping pattern, with cold-mop application and nails to attach it to the roof deck. Overlapping seams are sealed with tar.

Rolled asphalt flat Roof in Providence, RI is failing prematurely - seams coming apart, seam adhesive fails, nails backing out, and as a result: roof leaks inside the house.

Problems associated with flat roofs:

The nature of flat roofs’ problems is just that they are flat. Water does not run off the roof. Proper drainage must be in place to get rid of water accumulating on a roof. Usually older roofs are not leveled, so water puddles will appear here and there after every rain, and just sit there until it dries out. This is called standing or ponding water. Most roofing systems were not designed for ponding water. In fact, most manufacturers of the roofing systems on the market today, will void out the warranty if there is ponding water on the roof (we will get to this issue later). Other major problems for flat roofs, are penetrations such as skylights, vent or exhaust pipes, chimneys, roof hatches, drains, etc. However the biggest problem with flat roofs is the seams, because they are the most common areas where leaks occur.

Seams:

Seams exist on every flat roof (except tiny ‘6×10 porch-type’ roofs, which can be covered with a single sheet of roofing membrane), and are usually put together with some sort of adhesive. After a few years the adhesive breaks due to severe weather changes (here in New England, temperature can change 25 degrees or more, in a matter of one day). Another major factor affecting seams’ adhesive is condensation, which always occurs underneath the roof covering. Condensation expands both in the winter and summer. The most dramatic expansion of condensation happens in the winter time when water freezes, expands and breaks the seam. The same happens to our roads. Think of all the potholes you drive over. Those too were caused by water freezing. In the summer water heats up and also expands. When you see bubbles on the roof surface, it is the water vapor lifting the membrane. The third major factor is actually quality of workmanship and the adhesive itself. For different roofing systems the process is different, but most of them share the same shortcoming – the need for using adhesives, be it glue, hot tar, liquid resin, etc. Adhesives are also required to flash any roof penetrations listed above, but here the workmanship is actually more of a factor than the adhesive.

Conclusion – let’s get real.

It is a shame that in the 21st century we are still using 19th century technology. Even more so, because nearly 50% of roofers in the on-line construction forums will advise you to choose a clearly inferior roof. These heavy and dirty roofs, heat up to 170 degrees and make your AC run like crazy in the summer. These very roofs start leaking prematurely and are impossible to fix. Why would some one acting in good faith actually recommend these? The answer is obvious – they don’t know any better. Fortunately there is ONE modern, technologically advanced flat roofing solution available on the market today – IB Roof. In fact, this solution has been around for a few decades now, and has a proved track record of 30 years of leak-free service!

Read more: Part II – Single-Ply Roofing Membranes – PVC, TPO & EPDM Rubber Roofing.