Is the Roof Insulation’s R-Value Guaranteed?
Is it the BEST Value?
Many times Polyisocyanurate (Polyiso) roof insulation is specified because it comes standard in NDL (No Dollar Limit) Roof Warranties. No Dollar Limit Roof Warranties sound good but does it guarantee the R-value of the insulation? Would you be surprised if the answer is no, it doesn’t? This can provide a great “Value Engineering” opportunity for your project. NDL Roof warranties using Polyiso are not free. Some believe they are “overpriced extended warranties” that force you to buy all the components from one source, which in turn, drives up the cost of roofing. So ask your roofer what type of insulation he is using and then ask him to give you an option to use Engineered EPS from Plymouth Foam.
The technological advancement for Engineered EPS is truly amazing and the new research is showing why you should insist on using Engineered EPS Roofing Insulation on your project. The real secret is EPS is the best value in roofing. Not only is it less expensive, it is the best value in roof insulation for many reasons.
• EPS’s R-value stays consistent over the life of the product and we guarantee it!
• In cold weather, Polyiso’s R-value goes down, our Engineered EPS goes up.
• Safer product - no offgassing, no CFC OR HCFC and 100% recycable.
• Closed cell that resists moisture but has the ability to expel it faster.
• Compatible with other rigid insulations for mixed systems.
• Available in 12 various compressive strengths
Want to save money on a project? Ask your specifier to value engineer and use Plymouth Foam EPS. The saving will surprise you.
Need more help convincing the specifier that Plymouth Foam’s Engineered EPS is the best product? Ask us for our substitution package.
For more information contact us at
The most widely used green building certification program, LEED (Leadership in Energy and Environmental Design), recognizes buildings that contain products with favorable environmental impacts as determined through EPDs. Recognition as a preferred product requires that the product demonstrate an environmental impact less than the industry average in at least three of the following categories: global warming, ozone depletion, acidification, eutrophication, smog formation and total energy. For polystyrene foam insulation, EPS is less than the industry average in four of the categories, thus meeting the optimization requirement. From a LEED perspective, EPS is a preferred product in the polystyrene foam insulation category.
(Full Technical Brief)
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Bidding a project and Wondering why XPS 250 (R-10)
is specified for foundation insulation?
XPS (Extruded Polystyrene) and EPS (Expanded Polystyrene) are both closed cell rigid insulation that have the same compressive strength abilities. Many Specifiers and Contractors do not really understand the difference. You should! There is a BIG cost difference.
Many Specifiers and Contractors believe that XPS insulation provides a consistent R-value of R-5/inch in foundation insulation. Not even close. Two reasons: One, XPS uses a blowing agent that provides additional R-value that escapes and over time lowers the R-value. In fact, the federal government has now stepped in and mandated XPS rate their product using the R-value method of LTTR (Long-Term Thermal Resistance) as of October 2019 (see Full Disclosure Article). According to new research by the EPS-IA, XPS insulation’s 50 year age adjusted (LTTR-50) R-value is estimated to be 4.3 R-/inch. Two, research has shown that XPS placed below grade loses 48% of its R-value. This is due to the cell structure and manufacturing process of XPS. The study concluded that once XPS takes on water it has a hard time breathing it out.
Insist on Plymouth Foam Engineered EPS
The technological advancement for Engineered EPS is truly amazing and the new research is showing why you should insist on using Engineered EPS Foundation Insulation on your project. EPS’s R-value stays consistent over the life of the product and we guarantee it! EPS Type IX (250) has a R-Value of 4.35/inch. EPS is a greener product as it does not off-gas a harmful blowing agent and it is 100% recyclable. Want to save money on a project? Ask your specifier to value engineer and use Plymouth Foam Engineered EPS. The saving will surprise you.
Need more help convincing the specifier that Plymouth Foam's Engineered EPS is the best product? Ask us for our substitution package.
Plymouth Foam wants you to know the facts about Airpop® EPS so that you can sort through misconstrued information; looking at the environmental impact of any material requires considering all the facts. We need to look at how the material functions, what are the total energy costs to produce, and how the material is recycled.
Some people claim EPS is bad for the environment but they have not taken these facts into account:
- EPS is recyclable and recycling rates are climbing especially post-consumer recycling. Chemical recycling increases the ability to recycle contaminated EPS waste. There are more paper cups than EPS foam in landfills.
- Alternatives require more energy to produce, creating an even greater environmental impact. The American Chemistry Council sponsored a study showing the environmental cost of alternatives is 4 to 5 times more.
- EPS alternatives don’t function the same. You’ll see consumers “double-cup” hot coffee in paper cups or use an extra cardboard coffee sleeve. Businesses pay higher transportation costs for heavier packing materials that lack the same cushioning and impact resistance resulting in potential damage to the finished product. Perishable food would be wasted if not for the insulating benefits of EPS.
Contact Plymouth Foam when you need a collaborative solution for your delicate packaging and temperature sensitive storage solutions.
Contact GoPlymouthFoam for Construction questions or solutions.
Reprint from Plymouth Foam - July
Having trouble insulating a masonry wall. Gold-Wall to the rescue! This fast innovative insulation system offers high energy saving performance and does not promote mold, rot or thermal bridging. It is simple to use. Fasten the Gold-Wall through the built in metal furring studs to the wall, fasten the drywall (or other claddings) to the same stud... that's it, easy!!!
Ever since I saw my first bullt-up roof blister caused by off-gassing of Polyisocyanurate Insulation (1988), I have been analyzing and studying R-values in insulation. My major concern and conclusion was that R-value was not being stated correctly. This made predictive energy modeling and utility cost estimating not very reliable, not to mention over paying for overstated R-values. I believed that full disclosure through a method like LTTR (Long-Term Thermal Performance) would help with give a more accurate accounting. (LTTR - Read Article)
This October 2019, the US Federal Trade Commission will finally close a loophole in regard to Extruded Polystyrene (XPS) and their avoidance to “fully reflect the effect of aging” on their product. “The final rule, though not mandating a prescriptive LTTR method, requires that manufacturers publish R-values” that are more accurate.
The EPS Industry Alliance in a recently published paper, (Polystyrene Foam Insulation in Long-Term Building Applications, Effective R-Values) provided a method to estimate effective R-value for polystyrene insulation. This has started to address my two biggest issues with Effective R-values - 1) “Long-Term” and 2) testing temperature of 75ºF.
Long-term testing statements in insulation should not be 5-15 years (we don’t build building to last 5 years) but rather 50 years. So what is the average R-value over 50 years in a building? Fifty year testing is more reflective of homes and buildings insulation life cycles. Even though the Federal Trade Commission is mandating LTTR for XPS, they are still leaving a loophole by allowing “open” LTTR test methods and not requiring a 50 year prescriptive method. It will be interesting to see what the XPS industry comes up with for R-value. Will it be 4.3r/inch like the testing showed from the EPS Industry Alliance?
The issue of “Testing Temperature” has bothered me for years. Why test at 75ºF? Who needs R-value at 75º? In the Northern States, where heating is a concern, it is more realistic to look at R-value testing temperature at 40º, if not 25º in some states. The opposite is true in the South during summer where 90º may be a more reflective testing temperatures. Knowing the R-value performances of insulation, at various temperatures, is critical for designers to make important R-value decisions. They would have the ability, based on their climate, to select the most appropriate insulation. However, the current testing temperature approach of 75º is really a “one shoe fits all” approach and is not very helpful and leads to poor energy conservation decisions.
It has taken over 30 years to see a more accurate accounting of what the R-values of rigid insulation really is and I applaud the FTC for one more step forward. Just 2 more to go - 50 year LTTR and Variable Temperature Testing Disclosure. Accomplish that and we can finally focus on a really important issue — moisture in insulation and its effects.
John Calkins - JC Edison and Associates
A few weeks ago, I noticed an item in a foundation specification that I have been glancing over without any real thought. “Rigid, cellular thermal insulation with closed-cells and integral high density skin, complying with ASTM C 578.” What caught my eyes was integral high density skin. Are they trying to call out a specific for Extruded Polystyrene (XPS) Insulation because standard Expanded Polystyrene (EPS) would not naturally have a skin without adding it?
This triggered a technical conversation about skins on Rigid Insulation.
Does rigid insulation need a skin? What are the advantages or disadvantages of having a skin?
It is always helpful to go back and review the main function of insulation. Insulation’s main purpose is to insulate and provide R-value. Knowing the main purpose of insulation, do insulation skins provide more R-value? Skins can add R-value and skins can reduce R-value. A foil faced insulation could add R-value when it is used in the right circumstances such as a gap behind a masonry wall. Some skins like a clear poly laminated has no effect on R-value. Does an integral high density skin in XPS offer additional R-value? No, in fact according to newer research, it may have the opposite effect. How can this be? Why specified it as something important?
During a manufacturing process, XPS creates a type of skin during the extruding process and some call this an integral high density skin. This skin is maintained on the face and back of the board but the sides and the ends are trimmed during the manufacturing process. Many believe that trimming the sides actually expose and opens the board to moisture infiltration at a higher rate. The face and back have this skin but the ends and sides are open. Interesting, when you consider below grade insulation and how water moves down the foundation wall, water hits the top part of the insulation and water wants to enter in, however the top end does not have the integral high density skin. We know by testing, when XPS insulation is installed below grade, it takes in moisture and its R-value is reduced by 48%, from 5 R/inch to 2.6 R/inch. Some believe this phenomena is caused by water entering in easier at the edges and partially trap in by integral high density skin. So specifying this integral high density skin as a benefit, ultimately points out another reason not to use XPS below grade. Why pay a huge premium for XPS Insulation and get 1/2 of its R-value performance?
What about skins on EPS? Standard EPS does not naturally have a skin, however another advantage of EPS Insulation is that skins can be added. Many different types of skins with different properties can be added. A few examples of skins are ones that can be reflective, skins that allow permeability, skins that are vapor retarders and even skins that can provide high strength. In foundation insulation, where EPS is more effective, a permeable skin could be added to give even more strength. This skin could be even more effective against rough backfilling and fastener pull. This type of product would function great allowing any moisture that enters into to the insulation board to flow freely out and not trap the moisture in.
In this case, the specifier thought that XPS insulation with an integral high density skin would be a better product for below grade application. Unfortunately, it's not. With research showing that XPS insulation can loss 48% of it’s R-value below grade, Engineered EPS Insulation is a much better, safer choice.
Frequently asked questions. As an industry leader, we feel it is important to share our expertise as well as continue to educate and inform others of Plymouth Foam’s materials capabilities and industry trends.
Within the last few weeks, our industry has been in a negative light regarding the recent New York City ban of Airpop® EPS single-use containers. Store and restaurant owners can no longer use Airpop® EPS containers or packing peanuts. We want to remind our followers that Airpop® EPS is safe for you and your family. Here are a few details for you to read!
There have been many studies completed for different applications of Airpop® EPS. On FoamFacts.com, single-use food service packaging products are more sanitary than reusable china and glassware! Explained on FoamFacts.com, they share the following research; “ Las Vegas found 18 percent of reusable items tested had higher than acceptable bacterial counts. A similar study in Sacramento County found nearly 30 percent of reusable items tested had higher than acceptable bacterial counts. And a third study in Wisconsin discovered that unprotected tables and trays had up to 23 times higher bacterial counts than those with single-use place mats and tray covers.”
In the U.S., the federal Food and Drug Administration (FDA) strictly regulates all food packaging materials, including polystyrene. For every material used in food contact, there must be sufficient scientific information to demonstrate that its use is safe. The FDA has determined that Airpop® (EPS) is safe for use in food contact.
We would like to remind our followers, our Airpop® (EPS) material is made of 98% air and polystyrene does not carry harmful chemicals during use or disposal. Please keep in mind that the material has to be stamped with the #6 PS logo to recycle.
So YES! Airpop® EPS is safe for you and your family!
Reprint From Plymouth Foam
Many contractors have an impression that SIPs are hard to install or are expensive. Someone has given them bad information. Let’s explore the real truth about Structural Insulated Panels.
Expanded Polystyrene (EPS) SIPs account for about 90% of the SIPs market. EPS SIPs is one of the easiest and quickest energy efficient structural systems that is available and code approved in the United States. Notice, I said, “EPS SIPs.” EPS SIPs are easy to install.
What can make installing some types of SIPs more difficult? The difficulty of “field modifications” such as a window opening change. For the EPS SIP, modifying a window opening (example: moving it over 2 inches) is fairly simple. The foam and OSB is easy to cut and move. What makes EPS SIPs so simple is the that the foam is easy to manipulate and cut. Even installing electrical wiring through EPS SIPs is extremely easy. (Click to learn more)
The people that may say SIPs are hard to install are most likely talking about urethane SIPs - the yellowish insulation. Yes, this type of SIPs panel are harder to work with as the insulation is hard to manipulate and modify. Modifying electrical wiring is also very difficult. The bottom line is very few of these Urethane SIPs are sold. It is probably best to stick with EPS SIPs and avoid the hassle.
Finally, what about SIPS being expensive? EPS SIPs are not expensive, most of the time they are misunderstood. (Click and review the five elements of SIPs cost) No other structural energy efficient system on the market is faster to install and more economical. Studies have show that to get the same performance from other systems, many more steps are needed and they are never quite as good.
If you have never tried using SIPs before or it has been a long time, this may be the year that you discover what makes them so impressive.
Do you have plan that you want to explore, have a question or need panels, contact us.
Frequently asked questions. As an industry leader, we feel it is important to share our expertise as well as continue to educate and inform others of Plymouth Foam’s materials and capabilities.
Compressive strength is a crucial component for insulation and building materials. One of the most important mechanical property of Plymouth Foam's EPS is the resistance to compressive stresses, which increase as the density becomes higher. The compressive resistance is between 10 – 60 psi for most construction applications. Our Plymouth Foam product can be produced to meet your specific strength requirements per project needs.
Plymouth Foam DuraSpec Compressive Properties
Plymouth Foam DuraFill Geofoam Compressive Properties
Standard Specification Test Methods for Plymouth Foam DuraSpec EPS are as follows:
- ASTM C578, Standard Specification for Rigid, Cellular Polystyrene Thermal Insulation: types, physical properties, and dimensions of cellular polystyrene used as thermal insulation for temperatures from -65 to 165°F. ASTM C578 covers types of EPS thermal insulation currently available and the minimum requirements for the properties considered most important.
- ASTM C203, Test Method for Breaking Load and Flexural Properties of block-type thermal Insulation; flexural strength and compressive resistance values are included.
- C165, Test Method for Measuring Compressive Properties of Thermal Insulations and/or
- D1621 for Test Method for Compressive Properties of Rigid Cellular Plastics.
The EPS Industry Alliance shares Plymouth Foam DuraSpec EPS high resiliency and strength characteristics, expanded polystyrene insulation offers:
- Absorption of substrate and facing movement caused by temperature changes and structural deflections
- Absorption of substrate irregularities
- Thickness recovery following excessive construction load exposures
- Suitable subgrade reaction for effective load distribution
Recyclable and biodegradable are two terms that can get confused. We’re here to help understand the difference.
Let’s start off with the term: recyclable. The definition from dictionary.com states…
Recyclable: to treat or process (used or waste materials) so as to make suitable for reuse.
YES! Our material EPS (Expanded Polystyrene) is made of 98% air and is an inert material without harmful chemicals that off-gas or leach during its use of disposal. EPS is 100% recyclable. Many EPS users do not know of it’s recycling capability.
By The Numbers (2016 Domestic EPS Recycling):
The EPS Industry Alliance shares Airpop® (EPS) packaging recycling stats.
- 63 million pounds Post-Consumer
- 55.7 million pounds Post-Industrial
Biodegradable: capable of being decomposed by bacteria or other living organisms.
Biodegradable is a different concept. EPS breaks down slowly making it a non-viable biodegradable product. Common substances that are biodegradable include food scraps, cotton, wool, wood, human and animal waste.
Although EPS is not biodegradable, it can be recycled and reused. We are a proud industry supporter of this initiative in conjunction with our own sustainability efforts.
See our Video by clicking here!
We have been observing the approach of designers using the point load bearing calculation method and specifying insulation strong enough to carry that presumed load. Most of them used the triangular load path calculation. The thought process of the designers, were a conservative approach, the more PSI insulation strength the better - a type of “over engineering.”
Is this over engineering approach good? Does it have a detrimental effect on a structure? The Geofoam Industry (foam insulation beneath highways) learned the hard way and have adjusted their approach. They concluded that loads on slabs should not be look at as “Concentrated Triangular Point Load” but more in line with a slab that works more uniformly as a system as concrete slab distribute loads are more in an even fashion. The DOT and Geofoam Industry took a new approach to load issues. Use the least Compressive Resistant Geofoam Insulation that can handle the load.
How does this information translate to below grade insulation in residential or commercial construction? This is where it gets interesting. Everything we learned and accepted, in regard to, below grade insulation, by the XPS Industry, has been misguided. We have really only looked at half of the equation and most of the time, we have only considered point loads instead of slab distribution loads. We have been concentrating on loads from the top down only. In most ways, we have been ignoring what the soil is really doing below - not just what the soil can bear. Why you ask? Maybe because it gets too complicated. Not making this a forum on soil engineering, let’s just simply say soils are not always consistent and are constantly moving.
So this brings up many questions including - how does soil engineering effect below slab insulation? What are the effects of expansive soils on insulation? Is over engineering insulation compressive strength on slabs bad or harmful?
When we intersect structural engineering and geotechnical engineering, we find that in most cases - “Less is Best.” The lower the compressive strength, that still meet load requirements, is best. The insulation should act more as a stress cushion. Once the insulation has been in place for sometime, it should continue to act as a stress cushion.
The Theory of Plates on Elastic Foundations is a great way to calculate slab deflection and the resulting stress. The formula is (P/8)√(K/D). (Paper written by Timoshenko and Woinowsky-Krieger) We have been following these calculation in Geofoam for sometime now and have had less structural issues and have reduced Geofoam costs dramatically.
In regard to below grade insulation in residential construction, using products like XPS 250 with a 25 psi compressive resistance, as a standard, is not taking into account all of the factors in construction. This standard can be doing more harm than good. Because of the marriage of geotechnical and structural engineering, the industry has now began to understand this and revised its position on below grade insulation. It is time to move to these new standards.
Plymouth Foam is viewing this “Less is Best” change to run parallel with their research. We believe that this concept can reduce construction issues. Using products that are 10, 12 or 15 psi will have more advantages to the structure and in the end reduce cost. We call this the true definition of Value Engineering.
By John Calkins
Green Roofs continue to grow in popularity, especially in large urban areas. These areas can suffer from the “Heat Island Effect” which is caused by black roofs, black asphalt parking lots, concrete and lack of green space. Green roofs, also known as “living roofs” or “vegetated roofs” use plants to lower roof temperatures and create a biodiversity ecosystem encouraging additional habitats of plants and animals.
Plymouth Foam has been involved in numerous green roof projects and have noticed that Engineered DuraFill EPS (GeoFoam) has turned out to be the best solution. Here are the reasons we discovered:
- DuraFill EPS is a closed cell, yet breathable to expel moisture
- DuraFill EPS holds its R-value and does not leach chemicals
- DuraFill EPS can be manufactured formed to accommodate water flow
- DuraFill EPS has high compression resistance for loading
- DuraFill EPS has larger payback and lower costs
Plymouth Foam’s DuraFill Green Roof Products can help reduce cost by combining several products into one combination product reducing labor installation costs. Where most systems have insulation above the waterproofing membrane exposed to moisture, DuraFill can be engineered to move water more efficiently to the drains. DuraFill EPS can be designed to have predictable compression for walkways, loads and foot traffic.
Using your roof to create garden or outdoor living space can greatly reduce your heating and cooling costs. It can also help to reduce the Heat Island Effect.
A properly designed Geofoam Green Roof can increase the life span of the roofing system by improving water flow, reducing ultraviolet exposure to the roof membrane and reducing insulation below the waterproofing membrane which lowers thermal roof stress.
Before we delve into the “whys” we really should look at the effects of ponding water on the roofing system. Ponding water can have the following effects:
- additional loading to the structure
- additional time for moisture pathway to open and allow intrusion
- accelerated material degradation including reflectivity and sunlight magnification
- freeze/thaw pressure from moisture seeping into cracks
- insulation compression
- dirt and debris build up that can cause mold or plant growth
- safety issues - electrical or slipping and falling
- voids warranties
The effects of ponding roof can be a safety issue as well as a serious financial issue. If most roofers are aware of the hazards of ponding water then why are there so many roofs that do not drain well? What are the common causes for poor drainage?
- structural deck deflection
- weep hole’s on connected building sections too low
- no or poor structural slope
- poorly designed tapered insulation system
- cost cutting
- poor detailing
- drains/scuppers/gutters plugged
After walking and inspecting millions of square feet of roofing, I have come to the conclusion cost plays a sad, but significant role. I believe roofers feel cost pressure from owners that do not fully understand the ramifications. I will share some examples.
- A roof that has deck deflection issues, retrofitted for cost savings instead of torn off and the deflection was not addressed properly.
- I referred “poor detailing” but what I really meant was that the good detailing was too expensive and the standard detailing was used as it was ok in the book. (example of this, HVAC units that stop the flow of water drainage and needed to be raised and saddles installed to divert water around the unit - not done… not in bid or too expensive or a pain/time to disconnect.)
- Another one I hear is that Polyiso tapered insulation is to expensive and I can go with a 1/8” pitch, that should work.
- Weep holes, I can’t go above the weep holes, its too expensive to modify or change.
I understand the competitive world of bidding but I have some recommendations that can Keep Your Standards Up and Your Cost Down. I hear building owners constantly saying, “ I want things done right.”
RECOMMENDATIONS: Keep Your Standards Up and Your Cost Down
- Instead of using overpriced Polyiso, value engineer and use EPS for the tapered. - save money. Learn about cost saving in EPS
- Use 3/8” tapered as a minimum instead of standard 1/4” as it moves the water better and can overcome many of the detail or structural slope issues. Learn More
- Disconnect units and other projections for proper height requirements and proper water flow.
- Learn how to move weep holes which can offer the ability to increase insulation heights and have better drainage.
- Use EPS saddle and crickets to make sure water moves around units, projects and even between drains. Saddles can be a roofers best friend.
Many myths about rigid insulation have been spread over the years, especially concerning EPS. Some of these EPS myths refer back to an extinct product called bead board. Modern day Engineered EPS is so different and technologically advanced, it’s amazing some still get confused. EPS have made major advancements in chemistry, fusion, expansion, steam quality and TQM. Plymouth Foam, the leader in foam, has state-of-the-art proprietary manufacturing technology to make the product even better.
Lab and field research have lead to new conclusions about the two rigid insulations especially in below grade applications. EPS rigid insulation is certainly been found to be superior to XPS in so many ways. The following is just 12 reasons why.
1) Higher R-Value Retention:
EPS does not suffer from the same plight as XPS in regards to “Off Gassing.” XPS has blowing agents that initially give it a higher R-value, but these gasses escape over time, lowering the R-value.
Engineered EPS can be made in various densities and can achieve compressive strength up to 8,640 lbs/ft and flexural strength up to 10,800 lbs/ft. It is amazing that such a light product, that is 98% air, is so strong.
3) Moisture Management
EPS insulation is non-hygroscopic and does not readily absorb moisture from the atmosphere. Its closed-cell structure reduces the absorption of moisture into the insulation material yet it can readily expel any absorbed moisture.
4) 100% R-Value Warranty
Due to the R-value stability of EPS, Plymouth Foam offers a lifetime limited 100% R-Value Warranty. XPS offers a 90% R-value warranty.
5) No Harmful Chemicals
EPS does not have VOCs or other harmful chemicals in its product. XPS use of chemical HFCs has been deemed to have a high GWP.
6) Cost Advantage
R-value cost per inch is far less in EPS insulation vs XPS Insulation. Value engineering can be used to save $1,000s on projects.
7) Superior Bonding
Due to the manufacturing process, EPS and XPS provide a far different exterior surface. EPS cell structure provides superior bonding.
8) Made in USA - Made in Wisconsin
Plymouth Foam’s EPS is made in Wisconsin and brings jobs, reduces taxes and helps create a better economy for our state. Made in USA.
Engineered EPS is superior in customizing thickness, lengths, shapes, tapers, chases and can even have reflective laminates attached.
10) Smoke Development
ASTM E84 test method for burning characteristic show that typically EPS has a lower smoke development than XPS.
11) Lower GWP
EPS, the safe insulation, has a lower Global Warming Potential than XPS. Transportation costs are usually lower also lowering GWP.
12) Recycle Accessibility
With over 200 EPS recycling centers in the United States it is easy to see that not only is it 100% recyclable, but it easy to do.
(Learn More about these 12 reasons)
As EPS continues to grow even more popular and gain market share, competitors have continued to spread these old myths. The bad news for them is these myths have been BUSTED. Numerous studies done around the world are proving that EPS is not only “the safe insulation” but that it holds its R-value better, is extremely durable, great in freeze-thaw cycling, has great drying potential and outperforms all other rigid foam insulations.
(Get the 12 Reasons Brochure)
The most popular solution is adding some insulation and retrofitting a new roof membrane over the top. This is were roof insulation Flute Fillers play an important role. Not only do they add R-value to the system but they can transition a flat surface for a new roof retrofit system. I typically see flute filler level with the top of the ribs/seams and one additional layer on top of that smoothly bridging the top of the ribs/seams. The question is can this system be improved upon?
The one area of thermal weakness in this system is where the original metal roof has seams (connection point of the two pieces of metal roof) that allow heat loss at those points. By installing only one layer of insulation over these seams, it allows for the potential of thermal loss at these junctures were the insulation joints meet these metal roof seams. This thermal loss could cause condensation and stress the membrane disproportionately causing future issues.
Some may say, there is insulation under the metal roof system already, those joints don't leak heat. Really? Take an infrared camera and scan that metal roof and look at the seams, you might be surprised what you find.
There are two solutions to fix this potential problem with retrofitting over a metal roof. The first solution is to add another layer of insulation and offset the joints. The second solution is to use Plymouth Foams RetroDeck™ with a cover board. This system has a built in seam offset. No roofing system is perfect, but eliminating as many potential problems can help a roof system last longer creating better value for our customers.
You’re bidding on a project and EIFS (Exterior Insulated and Finish Systems) is specified in the building package. Who do you rely on that it specified, bid and installed correctly? Where does the buck stop?
EIFS has make huge advancements in technology, systems and installation details. The biggest advancement for our northern climates has been drainage or moisture management. Advanced design EIFS systems use a drainage cavity to move unwanted moisture out. This concept is monumental and removes many of the old design flaws with EIFS.
Here is where knowledge can lower your risk and pay off for you. Insist that your EIFS system only uses EPS insulation. Why?
Good building practices and todays advanced EIFS systems' goals are to discharge any stray moisture as quickly as possible. What about when that moisture finds its way into the insulation? Good Question! We know from studies that XPS (Extruded Polystyrene) insulation has a difficult time discharging moisture. Moisture in EIFS systems can cause serious system failures such as cracking, blistering, peeling paint, structural rotting and even mold. EPS (Expanded Polystyrene) insulation, on the other hand, has the ability to breath and release off moisture much quicker. In test situation, EPS also has the ability to hold most of its R-value, where XPS losses 48%.
EPS Moisture management is a great reason to insist on EPS insulation in your EIFS system but here are a few more:
- EPS can be made into a variety of shapes
- EPS can be made in various thicknesses
- EPS can be made in various densities
- EPS offers a consistent R-value
- EPS is the Safe Insulation - no harmful HFCs
- EPS is 100% Recyclable
- EPS is a Better Value and Lower Cost
This is one of those cases where a less expensive product is much better and can lower your risk.
Learn more about EIFS
I noticed this year, Home Depot is making a big deal out of trying to reduce EPS (“styrofoam”) out of some of they're packaging and just substituting other plastics. They think it is great, I think it is foolish. That new packaged Home Depot christmas gift that doesn’t have EPS but cardboard and plastic, where does that packaging end up? After Christmas this year, look though people’s trash and you will discover that much of the paper and cardboard that can be recycled is not. Why? What did Home Depot gain?
Let’s talk about EPS for just a minute. There are recycling centers all over the US just for EPS. In fact, there are over 200 EPS collection centers and growing. Last year in 2016, over 118 million pound of EPS was recycled. That is a ton considering EPS doesn’t weigh that much as 98% of the product is air.
They say, Americans are lazy and we need stuff that is biodegradable to put in the landfills. They don’t think we are smart enough or motivated enough to recycle EPS. I think Americans are smart enough but we certainly could do a better job of educating the public on all these EPS recycling centers. We could do a better job of letting the public know that EPS is a resource rather than garbage. That EPS is 100% recyclable just like aluminum cans. We need to push our local municipalities to add Number 6 to our recycle bins. (Click on the Video below, it is really eye-opening.)
So this Holiday Season, I am adding to the phrase “Peace on Earth” to Peace on Earth and please recycle your EPS.
Learn More Plymouth Foam Recycle Center
Nation Wide Drop Off Centers
Video Recycling EPS
The biggest concern of condensation and its effects can be quit worrying for building owners and construction professionals. Water that forms in a system can cause damage such as:
✓ Corrosion of metal panels and components which can structural weaken the system
✓ Degraded and wet insulation reducing thermal performance
✓ Mold and/or mildew growth that can increase health risks
✓ Insect infestation which can contaminate systems
Condensation tends to occur in noticeable quantities and cause problems at surfaces where there is a sudden change of permeance, which causes an increase in local relative humidity sufficient to create dew point conditions. Condensation in metal roofs can be caused by air leaks around units, holes in vapor barriers/retarders, gaps in insulation just to name a few and no system is bullet proof. “Moisture moves by several mechanisms, including bulk drainage, diffusion (absorption), surface diffusion (absorption), capillarity, osmosis and convection.”
Condensation can occurs on a hygroscopic surface, such as wooden sheathing or insulation, then moisture is absorbed, lowering the vapor pressure and increasing the vapor pressure gradient, driving more moisture toward that surface.
Picking an insulation that is resistant to moisture and help stop condensation is important, but no insulation is 100% waterproof. When Polyisocyanurate (Polyiso/ISO) or Extruded Polystyrene (XPS) gets wet, they dramatically loss their thermal effectiveness. Engineered Expanded Polystyrene (EPS) has the ability to resist moisture but when it get wet has the ability to expel moisture. Most metal roofing systems are not waterproof but rather watersheds. Therefore, air can travel and flow through the upper metal roof system allowing drying to occur. Learn More Here is the Secret: EPS is the BEST Insulation Solution for Metal Roofs because it can expel moisture caused by condensation. EPS's R-value will stay stable and be an overall better value.
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Continuous Insulation, is defined as, “insulation that is continuous across all structural members without thermal bridges other than fasteners and service openings.” More important is the fact that Continuous Insulation increases R-value performance due to the non-interruption of wooden or steel studs.
“Furring out” a wall with studs or furring strips and then filling in the gaps with insulation is still a common method used on interior and exterior walls. Every stud used, lowers the R-value and thermal loss and/or thermal bridging occurs at this intersections. Advancement in understanding performance R-value through continuous insulation has lead to the importance of Gold-Wall. The advantage of Gold-Wall is not only a Continuous Insulation system, but it has the built in ability to allow for finishing attachments. These finishing attachments can be interior drywall or exterior clad siding like vinyl or steel. The possibilities are almost endless.
Gold-Wall, with its built in surface attachment stud, can be installed easily to most type of masonry walls. Gold-Wall can also be attached to steel studs, wood framing or even OSB/Plywood surfaces. Gold-Wall comes with a high performance poly facer laminated to the moisture resistant EPS foam board which increases durability, fastener holding and impact resistance.
Gold-Wall may be perfect for your next Continuous Insulation project. Learn More