Roof Talk 101 The Best Educational Roof Blog In America: January 2014

Tuesday, January 28, 2014

Roof Talk-101 What Is Polyiso Insulation and How Does it Help My Roofing System?

Polyiso is a closed-cell, rigid foam board insulation consisting of a foam core sandwiched between two facers. The facers are composed of various organic and inorganic materials, usually paper and fiberglass. It is widely used in residential and commercial markets for both roof and side wall applications.

What are the attributes of Polyiso insulation?

Polyiso insulation has many attributes. Polyiso provides:

The most thermally efficient rigid board insulation available in the marketplace - it has the highest R-value per inch of thickness.
A moisture-resistant foam core.
Compatibility with most solvents used in construction adhesives.
Excellent dimensional stability
Superior performance in fire tests – Polyiso meets the strict standard of both FM Class 1 Approvals (FM 4450/4470), UL 1256, and CAN/ULC S126M
A wide range of service temperatures
Long Term R-value (only roof insulation with third party certification)
A CFC- and HCFC-free product with zero ozone depletion potential
Recycled content in most products (see manufacturer for details).
Negligible global warming potential.
Availability throughout the U.S. and Canada.

Does Polyiso have a high R-value?

Polyiso has the highest per inch R-value of any insulation available. Because of its superior R-value, buildings that use Polyiso have lower heating and cooling costs than buildings insulated with other materials of the same thickness.

What is LTTR?

Based on consensus standards in both the United States and Canada, Long Term Thermal Resistance (LTTR) is a scientifically supported method to calculate the 15-year, time-weighted average R-value of roof insulation. All Polyiso manufacturers of the Polyisocyanurate Insulation Manufacturers Association (PIMA) have adopted the LTTR method as the exclusive means to measure thermal performance of permeable-faced Polyiso roof insulation. PIMA Polyiso manufacturers have certified LTTR-value products verified by the QualityMarkcm Program.

What is QualityMark?

The PIMA QualityMark Certification program is a voluntary program that allows Polyiso manufacturers to obtain independent, third-party certification for the Long Term Thermal Resistance (LTTR) values of their Polyiso insulation products. Polyiso is the only insulation to be certified by this unique program for its LTTR value. The program is administered by FM Global and was developed by the Polyisocyanurate Insulation Manufacturers Association (PIMA) based on work done at Oak Ridge National Laboratory and CAN/ULC- S770.

What are the environmental benefits of Polyiso insulation?

Polyiso insulation is an ideal choice for green building design, offering:

Reduced fossil fuel consumption.

Well-insulated buildings reduce the need for energy, thereby reducing air pollution and greenhouse gas (GHG) emissions. BOMA currently represents roughly 9 billion square feet of roofing area. Reducing energy consumption by just 10 percent in these roofs is equal to planting 344,922,103 trees - a huge reduction in atmospheric CO2. The planting of these trees would also :

Generate 10.7 trillion dollars of oxygen

Control 10.8 trillion dollars worth of soil erosion

Recycle 12.9 trillion dollars worth of water

Provide 21.4 trillion dollars worth of air pollution control

It would also be the equivalent of removing 42.7 million cars off the road for one year.

Highest Thermal Efficiency

Polyiso is the most thermally efficient insulation available in the marketplace, as determined using Long Term Thermal Resistance (LTTR) values, a 15 year time-weighted R-value. In addition, members of PIMA participate in a third party certification program – QualityMark – to validate these predicted thermal values. QualityMark is a voluntary program administered by FM Global, one of the nation's most dependable testing organizations

Zero Ozone Depletion Potential

All PIMA Polyiso manufacturer members produce rigid foam board with third-generation, zero ozone-depleting blowing agents. All Polyiso products are now HCFC-free and CFC-free.

Zero Global Warming Potential

All PIMA Polyiso manufacturing members produce rigid foam board with zero global warming potential blowing agents. This quality is critical as the impact of climate change is acknowledged as a worldwide environmental concern.

Recycled Content

Virtually all Polyiso insulation is manufactured using recycled material. The percentage of the recycled material by weight depends on the individual manufacturer and the thickness of the product. Many facers on Polyiso products contain up to 100 percent recycled materials.

ROOFTEC-LLC has been installing commercial roofing systems for over 30 years. We have the solutions you are looking for if you desire a new commercial roof or need a re-roof. ROOFTEC-LLC only uses the best products and installation practices to insure you have a worry free commercial roof. For more information visit us at. www.rooftec-llc.com.

Friday, January 24, 2014

Roof Talk-101 What Is A PVC Commercial Roof

Roof Talk- 101 What Is A PVC Commercial Roof?

PVC (Polyvinyl Chloride) is a thermoplastic polymer roofing material to provide protection against the elements and energy efficiency.

The Pros and Cons of PVC Roofing

PVC roofing is specially designed to withstand ponding water, because it is welded together with hot air to remove all seams, which prevents the passing of moisture. Also, plastic roofing is able to reflect approximately 90% of UV and other rays. This will lower the absorption of heat and, in turn, heavily reduce your cooling costs. Additionally, plastic roofing is fire-safe and highly suited to low slope roofs. However, plastic roofing has low strength, which means that it is not capable of holding high weight. Plastic roofing also tends to shrink which eventually causes leaks. Contact Roof 101 today to receive lasting plastic roof repair and maintenance services.

PVC Corrugated Roofing and PVC Roofing Sheet

PVC corrugated roofing is the most common profile for PVC roofing. Corrugated PVC roofing sheets are available in an extensive range of sizes, thicknesses, colors, and designs. Thinner plastic roofing sheet is used for domestic garage and small industrial buildings, and is an inexpensive roofing option. Although the thinnest plastic sheet is 200 times stronger than glass, its lifetime is significantly shorter than thicker plastic roofing sheet. Corrugated plastic roofing sheets that are combined with Micro Sealant technology have a life span of up to 35 years, and can expand/contract according to temperature fluctuations. And like all corrugated sheets, plastic corrugated roofing allows efficient water run-off.

ROOFTEC-LLC has been installing commercial roofing systems for over 30 years. We have the solutions you are looking for if you desire a new commercial roof or need a re-roof. ROOFTEC-LLC only uses the best products and installation practices to insure you have a worry free commercial roof. For more information visit us at. www.rooftec-llc.com

ROOFTEC-LLC

Tuesday, January 21, 2014

Roof Talk-101 Is A Metal Roof Better Than An Asphalt Roof?

After dealing with asphalt shingles, many people consider the wisdom of upgrading to metal come the inevitable replacement time. Here are four popular misconceptions that pop up when people compare asphalt shingles to metal roofing:

1. Weight

Even though many people think they must be heavier, metal roofs are usually a lot LIGHTER than asphalt composition shingles. On average, metal roofs weigh 1.4 pounds per square foot, while composition averages 2 to 5 pounds per square foot. A bonus of this extreme light weight is that many types of metal roofs can be installed over existing roof materials (like asphalt and wood shingles, for example) without compromising the roof structure.

2. Lifespan
Metal roofs will usually outlive composition roofing by a factor of 4 – or more. A lot of folks believe that just because most roofers prefer to install composition shingles, this is a reflection of their reliability and permanence. The truth is, it's an easy material to install and it doesn't take much training so just about anyone can do it. Another certainty for anyone installing a composition shingle roof: It WILL be replaced, and LONG before it's warranty expires. Because the integrity of a metal roof is not compromised by heat and sun like an asphalt shingle roof, it will perform its job many decades longer.

3. Warranty
It's shocking to many that the lifespan of an asphalt composition shingle has little to do with the warranty period of the shingles. But it's true that they have little relation. A 50-year warranty on a shingle is NOT an assurance that the product will last that long! If I had a dime for every time I've heard some homeowner say, “I'll take one of them 40 year shingle – that's more than long enough for me!,” I'd already be retired. Those folks just don't (or don't want to) believe that anyone could put that on the label if it “weren't true.” But a quick read of any asphalt shingle warranty will reveal that the manufacturer is making a distinction between the lifespan and product defects (they're NOT the same) and that the warranty is about defect – not deterioration. That 40 year shingle will need replacing in most parts of the country in 15-20 years, and the warranty won't have the least value to whomever owns the house at that time. Just look at these pictures of “50 Year” roofs that were less than 20 years when they required replacement. A metal roof won't let you down like that.

4. Aesthetics
Almost anyone who's looked at houses in North America would know what you meant when you said, “asphalt shingle roof.” They've been the cheap, fast roofing solution for nearly 100 years and they look like what they are – asphalt shingles. What amazes many outside of the roofing business are all of the shapes, styles, and colors that are available in metal roofing. Many folks only think of “rib roofs” when the topic of metal roofing is broached, but did you know that metal roofing offer more appearance options than any other type of roof material on the market? It's true – from shingles, tiles, diamonds, ribs, panels, and custom shapes, the appearance of metal can compliment any style of architecture – while lasting as long as the building itself.
It all adds up to making the extra
investment of a metal roof terrific value for anyone who cares about the longevity, appearance and performance of the roof they're buying. It only takes a little research to learn why so many people are choosing metal as their next roofing purchase.

ROOFTEC-LLC has been installing commercial roofing systems for over 30 years. We have the solutions you are looking for if you desire a new commercial roof or need a re-roof. ROOFTEC-LLC only uses the best products and installation practices to insure you have a worry free commercial roof. For more information visit us at. www.rooftec-llc.com

rooftec-llc.com

Thursday, January 16, 2014

Roof Talk-101 What Are The Benefits Of A Cool Roof

A high solar reflectance—or albedo—is the most important characteristic of a cool roof as it helps to reflect sunlight and heat away from a building, reducing roof temperatures. A high thermal emittance also plays a role, particularly in climates that are warm and sunny. Together, these properties help roofs to absorb less heat and stay up to 50–60°F (28–33°C) cooler than conventional materials during peak summer weather.¹

Building owners and roofing contractors have used cool roofing products for more than 20 years on commercial, industrial, and residential buildings. They may be installed on low-slope roofs (such as the flat or gently sloping roofs typically found on commercial, industrial, and office buildings) or the steep-sloped roofs used in many residences and retail buildings.

Through the ENERGY STAR program, EPA and the Department of Energy (DOE) help consumers and other purchasers identify the most energy-efficient roofing products. Roofing materials with the ENERGY STAR label have met minimum solar reflectance and reliability criteria. Based on 2006 data from more than 150 ENERGY STAR partners, shipments of cool roof products have grown to represent more than 25 percent of these manufacturers' commercial roof products and roughly 10 percent of their residential roof products.

Benefits and Costs

Cool roofs provide a number of benefits beyond urban heat island mitigation, including:

Reduced energy use: A cool roof transfers less heat to the building below, so the building stays cooler and uses less energy for air conditioning.

Reduced air pollution and greenhouse gas emissions: By lowering energy use, cool roofs decrease the production of associated air pollution and greenhouse gas emissions.

Improved human health and comfort: Cool roofs can reduce air temperatures inside buildings with and without air conditioning, helping to prevent heat-related illnesses and deaths.

Cool roofs deflect some desired heat gain during the winter. In general, though, cool roofs result in net energy savings, especially in areas where electricity prices are high.

Although costs will vary greatly depending on location and local circumstances, cool roof coatings on a low-slope roof might cost $0.75–$1.50 per square foot, while single-ply cool roof membrane costs vary from $1.50–$3.00 per square foot. The cost premium for cool roofs versus conventional roofing materials ranges from zero to 5 or 10 cents per square foot for most products, or from 10–20 cents for a built-up roof with a cool coating used in place of smooth asphalt or aluminum coating.²

A California study found that cool roofs provide an average yearly net savings of almost 50 cents per square foot. This number includes the price premium for cool roofing products and increased heating costs in the winter as well as summertime energy savings, savings from downsizing cooling equipment, and reduced labor and material costs over time due to the longer life of cool roofs compared with conventional roofs.

Federal tax credits are available for ENERGY STAR qualified metal roofs and reflective asphalt shingles that are installed on existing homes. For details, please visit ENERGY STAR’s Federal Tax Credits for Energy Efficiency page.

ROOFTEC-LLC has been installing commercial roofing systems for over 30 years. We have the solutions you are looking for if you desire a new commercial roof or need a re-roof. ROOFTEC-LLC only uses the best products and installation practices to insure you have a worry free commercial roof. For more information visit us at. www.rooftec-llc.com

Tuesday, January 14, 2014

Roof Talk-101 Don’t Ask If A Product Is Fire Rated, Ask If The System Is Fire Rated

Joel King
Director of Technical Services / Product Development

US Ply, Inc.

Over the years, I have made several trips to Underwriters Laboratory in Chicago, to construct roof system configurations and test them for fire resistance. It is amazing to watch how intense a fire can be and to appreciate the seriousness of life safety. Even standing behind the glass in the safety room, you can feel a portion of the heat radiating from a fully engulfed specimen as it is consumed by the 1400°F fire. After ten minutes has elapsed the gas is turned off and quickly the fire is extinguished. “Did we pass?” I have asked sheepishly – “yes, you did well,” is the response. How can that be? The answer is in understanding what a fire rating really means.

So when the question comes up, “is this product fire rated?” An answer without much explanation might leave the wrong impression or lead to choosing a system that does not meet the criteria for the desired “fire rating”.

First of all, most roofing products are “fire classified”, but not many products carry a class A, B, or C fire rating as a “stand-alone” product and for good reason. Fire classifications of A, B, or C are intended to be system ratings and not individual product ratings. Thus every product used within a rated system has a classification for specific inclusion within certain systems, but does not necessarily yield a certain rating by itself. To be more clear; the composition of a material may have certain ingredients that adds “fuel contribution” and certain ingredients that do not add fuel but rather “resist” burning. Anything that either resists burning or can effectively slow the rate of burn/spread is advantageous within achieving the goal of a particular rating.

For example, organic and petroleum based products are fuel contributors. Put another way: asphalt, polymers and other poly______ (fill in the blank) will burn! Other materials which comprise a given product may either burn at a slower rate or do not burn. Some of these materials are ceramic granules, metal clad materials, fiberglass mats, fillers such as limestone and other proprietary fillers. The general idea is to assemble the system in an effective combination that will sufficiently resist a fire within the specified time frame.

So how does that work? Before I answer that question, here is some useful information about fire rating classifications:

Fire rating classifications are determined by testing a roofing system in accordance with ASTM E 108, “Standard Test Methods for Fire Tests of Roof Coverings”. This test method is used by Underwriters Laboratory (UL Standard 790) and Factory Mutual within their own test protocols. The result is that the successful passing system is given the rating as tested as a system, not as a product.

To achieve a Class A fire rating there are two sets of criteria. One is for an assembly over “combustible” decks (plywood, oriented strand board and wood plank or wood board) and the other is over “non-combustible” decks (steel, concrete, gypsum, lightweight concrete and structural wood fiber aka Tectum®). Note: Factory Mutual only publishes Class 1 non-combustible decks and which also include an additional calorimeter test.

The criteria over non-combustible decks is more straight forward – the system must successfully pass a “spread of flame” test which measures how far the fire spreads in a given time period (Class A is tested with a 1400°F flame with a 12 mph wind and cannot exceed a spread of 6 feet in a 10 minute span, Class B is tested in the same manner and is limited to maximum spread of 8 feet in a 10 minute span, and Class C is tested with a 1300°F and a 12 mph wind and is limited to maximum spread of 13 feet in a 4 minute span.)

For combustible decks, there are two additional tests that are applicable; one is a “burning brand” test which measures the depth of the fire penetration in a given time. This is to ensure that the fire will not burn through to the deck during the test period. The other is known as an “intermittent” test, in which the fire is cycled on and off for an hour to also determine if the combustible deck becomes inflamed. That said, Class A is more resistant than a Class B and Class B is more resistant than a Class C.

The other factor is the slope. Fire spreads more rapidly as the incline increases, therefore; each rating has a slope limitation unless the rating specifically indicates it is for an unlimited slope. For low sloped roofs, it is more common to see ratings up to a maximum incline of ½” per foot, once the slope goes beyond ½” per foot, the system combinations get more difficult to pass with standard roofing materials.

The next time, you hear the question regarding whether a product is fire rated – the answer in short is probably yes – but whether it can be included in the desired system combination over a certain deck type on a given slope? That is the more appropriate question and the answer is listed in the Underwriter’s Laboratory Fire Classification Directory or online at www.ul.com. Additionally, the manufacturer usually has an index card file of system classifications which they have successfully tested.

Thursday, January 9, 2014

Roof Talk-101 TPO Maintenance Best Practices

When it’s in good condition, a thermoplastic polyolefin (TPO) roof reflects harsh UV rays and resists heat and chemical damage. Like all roof membranes, however, over time, TPO’s integrity can be affected by structural stress and environmental exposure, resulting in surface degradation, thinning and shrinkage. No roof lasts forever, but with a good maintenance plan, you can greatly extend the life of your TPO roof.

The Cost of Neglect

In the absence of visible leaks, many facility managers adopt the old “if it ain’t broke – don’t fix it,” motto. Unfortunately, by the time leaks show up, damage to the TPO membrane, the insulation layer and the roof deck could result in the need for costly repairs or complete roof replacement.

The expense to maintain a TPO roof is much less than the cost to replace it. Neglect can result in added expenses if leaks cause structural damage, inventory or equipment damage, operational downtime or financial loss due to health claims arising from exposure to mold.

Lack of maintenance is one of the biggest causes of premature TPO roof failure, ranking right up there with misuse and abuse, faulty workmanship and improper design. The best time to adopt a maintenance plan is right after the installation of the new membrane but older roofs will also benefit.

Get Your Records Together

Accurate records are essential for documenting roof-related events. Keep a file that contains the following:

Initial TPO roof specs and related construction documents
Roof modification records (such as rooftop equipment installation)
Detailed bid sheets, estimates and change orders
Manufacturer’s warranty documents
Inspection records (including photos and videos)
Repair and maintenance records

Initial Evaluation

A good maintenance plan starts with a comprehensive evaluation of the membrane’s current condition by a reputable roofing professional. Request a written report that includes a detailed survey of known problems, potential issues, recommendations and a cost estimate for repairs. A professional evaluation should include a visual inspection of the membrane’s surface, seams, fasteners and flashing. An infrared thermography survey can locate tiny penetrations that aren’t visible to the naked eye.
The inspector will look for voids or signs of deterioration in sealants around coping joints, coping ends and penetrations such as skylights and rooftop units. He’ll also be looking for inadequate or blocked drainage, ponding water and the condition of roof/wall tie-ins and parapets.

Taking the Guesswork Out of TPO Maintenance

ROOFTEC-LLC will check and repair sealants, seams and fasteners as necessary. Because certain products, like roofing cement, are not compatible with TPO, avoid do-it-yourself fixes, which can cause more damage.

At ROOFTEC-LLC, we know that inspecting, repairing and maintaining your TPO roof can be a daunting task for the typical facility manager. That’s why we developed the ROOFGUARD Maintenance Program, which allows managers to focus on their daily business without worrying about scheduling the inspections, maintenance and repairs necessary for keeping the roof in good shape and for keeping the warranty in effect.

ROOFTEC-LLC has been installing commercial roofing systems for over 30 years. We have the solutions you are looking for if you desire a new commercial roof or need a re-roof. ROOFTEC-LLC only uses the best products and installation practices to insure you have a worry free commercial roof. For more information visit us at. www.rooftec-llc.com

Tuesday, January 7, 2014

Roof Talk-101 What Is A Standing Seam Metal Roof?

Roof Talk-101 What Is A Standing Seam Metal Roof?
There are three general categories of metal roof systems used for steep-slope roofing applications: architectural metal panel, structural metal panel and metal shingle/shingle panels. Generally, architectural metal panel roof systems are water shedding and are intended for use on steep slope roofs. Structural metal panel roof systems are used on low and steep slope roofs. Structural metal panel roof systems can be used on low slope roofs because of their hydrostatic, or water barrier, characteristics.

Because architectural metal panel roof systems typically are designed to be used on steep slopes that will shed water rapidly over the metal panels' surface, the seams typically are not watertight. Many architectural metal roof systems are well suited for use on roof slopes of 3 inches per foot (14 degrees) or greater. One exception to the general slope guidelines for architectural metal panel roof systems is the traditional flat seamed, soldered or welded metal roof system, such as copper. It may be specified on slopes less than 3 inches per foot (14 degrees). Solid roof sheathing, or decking, is required for architectural metal panel roof systems, and NRCA recommends using underlayment.

Example of an architectural metal panel roof system

Most structural metal panel roof systems are designed to resist the passage of water at laps and other joints, as sealant or anti capillary designs can be used in the seams. Structural metal panel roof systems possess strength characteristics that allow them to span supporting members.

Example of a structural metal panel roof system

Metal shingles and shingle panels are available in numerous varieties for use as steep-slope roof coverings. Most of the metal shingles are press-formed during the manufacturing process to provide a variety of shapes. These products can take the shape of individual or multiple asphalt, tile, slate or wood shingle configurations.

Seam types

There are many categories of metal panels. The term standing seam often is used as a generic description for a class of metal roof seams. The name standing seam is derived from the fact that the seams are joined together above the panel flats. The term also is used to refer to a panel profile that includes a standing seam: the vertical leg/flat pan and the trapezoidal seam. The trapezoidal standing seam is more commonly associated with structural metal panels. Other panel types are batten, flat, bermuda and shingled.

The original batten seam consisted of vertical leg panels placed between wood batten strips and covered with a cap. Today, many batten seam panels are constructed entirely of metal. Because they are designed to shed water, batten seam panels primarily are used in architectural applications.

Example of standing seam profiles

A flat seam is created with individual panels applied in a shingled application. One panel edge is folded back on top of itself; the other panel is folded under, and the two panels are hooked together. Again, because flat panels are considered watershedding, they are more commonly found in architectural installations. Some flat seam panel systems, such as copper, are commonly soldered, which allows them to perform on less steep slopes.

Example of a flat seam

Roof deck

Architectural metal panel roof systems and structural metal panel roof systems are installed over a large variety of substrates. There are two general categories of substrates: continuous or closely spaced decking that provides solid support for the metal roof panel, and the other is composed of spaced structural supports (such as purlins) where the metal panels must span between supports. Most structural metal panels are used over spaced structural supports without being supported by a solid roof deck.

Metal shingles and metal shingle panels should be installed over continuous or closely spaced wood decking, furring strips, or metal or wood purlins using a batten or counter-batten system. These roof coverings typically are considered to be watershedding roof systems, so the roof slope should be 3:12 (14 degrees) or greater.

Underlayment

Underlayment (or "felt paper" as it is frequently called) is installed over the roof deck before the application of a metal roof system. An underlayment performs two primary functions: it provides temporary weather protection until the metal roof system is installed, and it provides a secondary weatherproofing barrier if moisture infiltrates the metal roof panels.

Asphalt saturated, nonperforated organic felts are among the most common underlayments; they commonly are designated as Type 15 and Type 30 or referred to as No. 15 and No. 30, which are reflective of a once used pound per square weight designation. The terms Type I and Type II now are used within the industry in lieu of No. 15 or No. 30, respectively.

For metal panel roof systems, metal shingles and metal shingle panels, NRCA recommends a minimum of one layer of No. 30 asphalt-saturated felt applied horizontally in shingle fashion on roof decks having a slope of 4:12 (18 degrees) or more. For roof decks having slopes of 3:12 (14 degrees) up to 4:12 (18 degrees), a minimum of two layers of No. 30 asphalt-saturated underlayment should be applied horizontally in shingle fashion.

Underlayments typically are not used with structural metal panel roof systems when intermittent supports are used to carry the roof systems. However, if there is a continuous or closely spaced roof deck, NRCA recommends an underlayment be installed.

In locations where the average temperature for January is 30Âº F or less, NRCA suggests installation of an ice-dam protection membrane. An ice-dam protection membrane generally is a self-adhering polymer-modified bitumen membrane.

An ice dam protection membrane should be applied starting at a roof's eaves and extending upslope a minimum of 24 inches from the exterior wall line of a building. For slopes less than 4:12 (18 degrees), a minimum of 36 inches is recommended. See Figure 1.

Figure 1 - Example of ice damming

NRCA also recommends a slip sheet be installed over the underlayment for metal panel roof systems. A slip sheet is a layer of smooth building paper, such as rosin-sized or unsaturated building paper. Its purpose is to protect the underlayment from damage, as the panels can adhere to and tear the underlayment.

Vapor retarders, insulation and ventilation

Condensation should be expected to develop on the undersides of metal roof panels. Careful consideration should be paid to vapor retarder, insulation and ventilation issues. Because every building is in some way unique, building owners and designers may need to consult moisture-control specialists.

Material standards

NRCA does not make any recommendations about which product or manufacturer to use; however, NRCA does recommend that metal roof systems meet standards established by ASTM International.

ASTM E1514, "Standard Specification for Structural Standing Seam Steel Roof Panel Systems"
ASTM E1637, "Standard Specification for Structural Standing Seam Aluminum Roof Panel Systems"