Water removal has become a pillar tenant for good roofing practices. The faster the water is off the roof the better. The old rule of thumb, "… it should be off the roof within 48 hours or it is considered ponding water." Why when I look at Google Maps satellite, do I see so many building with ponding water? Maybe the drains are plugged ? Really? I don't think so.
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?
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.
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.
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.
I am often asked what is the difference between XPS (extruded polystyrene) and EPS (expanded polystyrene) insulation? Which one is better and why?
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.
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.
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.
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.
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.
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.
Due to the manufacturing process, EPS and XPS provide a far different exterior surface. EPS cell structure provides superior bonding.
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.
ASTM E84 test method for burning characteristic show that typically EPS has a lower smoke development than XPS.
EPS, the safe insulation, has a lower Global Warming Potential than XPS. Transportation costs are usually lower also lowering GWP.
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.
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.
EIFS What To Know: Increase your knowledge and lower your risk.
The fastest way a construction contractor can increase their risk on a project is to not staying in control of knowledge of a building system - especially high liability systems.
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%.
This is one of those cases where a less expensive product is much better and can lower your risk.
Stopping Condensation in Metal Roof - What's the Secret?
Metal roofs over the past 10 years have exploded onto the construction sites. The ongoing problems and frustration for building contractors and design professionals of condensation in metal roofs has only increased exponentially. Solving this issue can be very difficult. Let's explore the benefits to rigid insulation and a secret, not known by many, in the building industry.
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.
The push for higher energy efficiency in commercial buildings is growing, driven in part, by the new energy codes. Another factor has been the Department of Energy studying of R-value in various wall systems and disseminating that information. The study called "Whole Wall R-value," has lead to a better understanding and promotion of Continuous Insulation.
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.
The Secret Moisture Control Leak - a dynamic new strategy.
The majority of recent technical discussions in building construction have been around Moisture Management. Many articles have been written on drainage plains, building enveloping and vapor retarders. The goal for moisture management is to keep a building lasting longer and performing properly. One area of moisture control or moisture management that has been neglected is foundation insulation.
Foundation insulation may be easy to overlook as many building professionals may be going under to old adage, "if it ain't broke, don't fix it." The serious reality is that in cold weather climates any structure that has a foundation that touch soil such as basements or frost walls needs to viewed differently in regards to moisture management.
Foundation insulation can be used for a variety of reason but the most important is R-Value. This is where it gets interesting - what does Moisture Management have to do with R-Value? Its all about building performance in real world applications.
We can explore permeability and the Laws of Thermodynamics and go very technical but for now most people know that when insulation gets wet, the R-Value of the insulation is reduced. This lowering of R-Value is a performance issue.
So now that we know what happens to insulation below grade how does that all tie back into Moisture Management? If you are not going to 100% envelope or water proof your below grade insulation or below grade wall system, EPS insulation should be used 100% of the time. Remember, the goal of Moisture Management - keeping a building lasting longer and performing properly - Its all about performance. If you want your below grade insulation performing properly and its going to be left "unenveloped," the best Moisture Management choice is EPS.
What Insulation is the Best in Roofing?
I get asked this question all the time, but the answer is much more complicated. Its fun to go back historically and look at why insulation was introduced into roofs in the first place. It was fairly simple back then, the waterproofing was to keep water out and the insulation was to keep people warm. Today, insulation is so much more and that is why to answer which insulation is the best, we need to look at the most important attributes of the two most popular roofing insulations - Polyisocyanurate and Expanded Polystyrene.
R-value is more than the R-value per inch. Polyisocyanurate (ISO), starts out with a higher r-value per inch, but then the blowing agents escapes and the R-value is reduced. (learn more) Expanded Polystyrene (EPS) has a lower R-value per inch but can be make thicker to match any R-value requirement. EPS's R-value increase in colder temperature while ISO decreases. Many would give ISO the edge because of R/inch, but taking into consideration overpaying for R-value that does not stay stable in lower temperature, the advantage has to good to EPS.
Roof design can be looked at in numerous ways such as thickness restrictions and tapered possibilities. ISO is very limited in thickness per board. High R-value systems make ISO more labor intensive as it need so many layer to comply. One EPS board can go up to 200 R. ISO is limited in tapered slope possibilities usually 3. EPS on the other hand is almost unlimited. EPS can use insulation shapes (example rounded) that ISO just can't match. Design flexibility goes to EPS.
Expanded Polystyrene, when compared to polyisocyanurate, certainly has more reason to be use in roofing. It seems over the last few years, many designer have lost sight of the purpose of insulation and the importance of R-value long-term. Some designer only considered combustibility and its superior importance, when in all likely hood this physical property will never ever be used. A feature such as long-term R-value, which performs daily in that system, or even moisture expelling capability, get lower considerations. When all of the major features of insulation are considered, EPS seems to be the clear winner.
Breaking away from the norm and thinking out side the box is what Lumber Sales & Products, Jackson, Wisconsin strived to accomplish. Using a wood stove and in-floor heating is beyond normal construction and took special design and engineering.
Instead of using the traditional pink or blue XPS insulation, Engineered EPS was used as the insulation beneath the concrete to dramatically help save energy. Not only does the EPS work better, but the cost savings was almost 30%. The cost savings for just the insulation was over $15,000. In addition, the saving on the supply lines, using EPS, was $7 per linear foot.
Do Roof Warranties Insulate You?
Building owners are constantly making decisions and risk assessment in regard to their facility. Roofing plays a huge role as it can impact so many factors.
When installing a new roof, (new construction or replacement) an owner is faced with the role of Risk Management. Many building owners believe the serviceable life of a roof is directly related to the warranty. Roofing Manufacturers' have seized upon these beliefs by selling "NDL (No Dollar Limit) Warranties" giving customers the euphoria of total protection. Are NDL Warranties worth it?
NDL warranties have a relatively high cost, at several levels. There is a cost per foot for the warranty and to qualify for the NDL, the "system" has to contain "everything" from the roofing manufacturer (screw, plates, insulation, etc.). Most roofing manufacturers do not make all the components in a roof system but rather put their name on them and mark them up.
According to Roof Warranty Research, roofs typically don't fail because of washers or insulation. So if insulation and other components, rarely if ever, cause roof failures, why bundle them into a warranty? Does the NDL warranty guarantee the R-value of the insulation when it declines or gets wet? Would you be surprised if I told you they do not?
Maybe bundling all these other components in a NDL warranty offers better cost? When the Roofing Manufacturers bundles the other components, it ultimately places a double margin on "all the other components" - 1st mark up from original manufacturer and the 2nd mark up from NDL Warranty Roofing Manufacturer. Does this double margin reduce cost or add extra profit for the roofing manufacturer?
Interest fact, the roof installers lose their competitive ability to "shop" all the other roof components, driving the prices higher. So, NDL Warranties really take Value Engineering away from the roofer and the building owner! In reality, it really hampers the free market system in some ways.
So are NDL worth it? It has long been said, that roof warranties are written to protect the manufacturer not the owner and that the best warranty is the one that you never have to use. What is a building owner to do? I suggest saving money and take the advice of the roofing experts, make sure the roof is installed properly, do proper maintenance and faithfully monitor the roof through inspections - this is how you get longer serviceable life, not through a NDL warranty.
What is your definition of long-term - 5, 10, 25 years? How should we judge the R-value of insulation long-term? LTTR (Long-Term Thermal Resistance) is a measure to quantify a comparative method of R-value in an attempt at trying to help architects, specifiers, builders, inspectors and owners. This measurement is achieved by the test methods ASTM C1303 or CAN/ULC-S770. I applaud the effort of developing these testing to quantify thermal performance, however a major adjustment may need to take place or at least the building industry need to understand these measurements - what they are and what they are not.
Early this year, the National Roofers Contractors Association, made a recommendation to it's members that Polyisocyanurate Insulation revise "its design in-service R-value recommendation to 5.0 per inch thickness." This declaration was the second time Polyisocyanurate's R-value was downgraded in the last 2 years. For some of us "Energy Aficionados," who understand the principles of insulation off-gassing, determined it was time to re-examine LTTR testing (View Technical LTTR Bulletin).
LTTR really looks at Long-Term Thermal Performance of insulation as 5 years. Do we expect a building to last only five years? How is 5 years a true quantitative analysis of R-value performance?
We do not replace insulation in a building every 5 years, why would we think that is long-term? Most building in the U.S. are built to last 50 years, some 100 years. Long-term R-value should be figured at 50 years… right? We know off-gassing continues to happen after 5 years. Let's re-evaluate what we are doing as an industry and modify Long-Term Thermal Resistance to at least 50 years.
The real question maybe why? and why another change after last year's change? The answer is independent testing. According to research conducted by BSC (Building Science Corporation) and others, "the thermal performance of some insulation materials changes as they age. The R-Value of Polyisocyanurate decreases as some of the gasses … diffuse out and are replaced by air." This is known by several names - Thermal Drift, Gas Replacement Process or Off Gassing.
What the research has shown is that unlike EPS (Expanded Polystyrene) Insulation that increases its R-Value when the temperature decreases, ISO Insulation R-Value actually goes down. Bottom line: In the north, when you need the r-value the most, its not there like we thought.
•	If you need to use ISO - the BCS Recommendation is to use it in a "hybrid insulation approach" with a cold stable R-Value insulation like EPS.
•	Try to substitute out ISO Insulation and use EPS or the New Neopor Plus Insulation.