Below Grade and Under-Slab Building Insulation

Originally posted in Modern Contractor Solutions Magazine, June 2014 issue

Modern Contractor Solutions Magazine, June 2014 Digital Issue

MC_june 2014

Modern Contractor Solutions, June 2014

Three tips for choosing the right material for your project

Which insulation is best for use on buried building foundations and under concrete slabs? Sales reps, naturally, will tell you that their company’s product is best. But, what does independent testing and research say?

These three tips will help your firm select a cost-effective and high-performance rigid foam insulation type for your next below-grade insulation job.

1.  CONFIRM LONG-TERM THERMAL PERFORMANCE

Two of the rigid foam insulations most commonly used below grade and under slabs are expanded polystyrene (EPS) and extruded polystyrene (XPS). Although both are closed cell insulations, they perform very differently over the long term.

XPS has a higher initial insulating R-value than does a similar thickness and density of EPS, but the R-value of XPS degrades over time. EPS does not experience such “thermal drift,” and the reported R-value remains the same throughout years of installed service.

This is a crucial point when selecting insulation, as a decreasing R-value means lower thermal performance over time, and thus increased heating and cooling energy and costs for the building owner.

Below Grade

Rigid foam insulation is increasingly common in below-grade and under-slab applications.

A simple way to confirm an insulation’s long-term thermal performance is to review the warranty. Established EPS manufacturers typically warrant 100 percent of the published R-value for 20 years. By comparison, most XPS warranties typically cover only up to 90 percent of the published R-value, to account for the R-value degradation that occurs in the field.

2.  ENSURE MINIMAL LONG-TERM MOISTURE ABSORPTION

In addition to R-value stability, rigid foam insulations differ in their rates of moisture absorption and their ability to dry. Wetted insulation provides lower thermal resistance and can degrade over time. Since insulation installed below grade frequently contacts wetted soil, rates of moisture absorption and the ability to dry is key in these applications.

Independent laboratories have conducted extensive tests of moisture absorption rates for both EPS and XPS. Although XPS often rates better in laboratory short term, fully submerged tests, real-world long term tests show that EPS performs much better. The reason is that EPS has the ability to dry much faster than XPS. This ability to dry at a fast rate helps EPS remain drier during conditions of repeated exposure to moisture.

A 15-year in-situ test of EPS and XPS dramatically demonstrated this point. Stork Twin City Testing evaluated the moisture content of EPS and XPS buried side-by-side for 15 years on a building foundation in St. Paul, Minnesota. At the time the insulations were removed, the EPS was much drier than the XPS—the EPS had only 4.8 percent moisture by volume, compared to 18.9 percent moisture content for the XPS. After 30 days of drying time, the EPS had only 0.7 percent moisture by volume, while the XPS still contained 15.7 percent moisture.

The high moisture absorption rate of XPS in real-world settings is further seen in a 2012 report from the U.S. Dept. of Energy’s Oak Ridge National Laboratory (ORNL). Their researchers found that XPS insulation installed below grade for 15 years had absorbed 67 percent or more moisture.

3.  TARGET AN APPROPRIATE COMPRESSIVE STRENGTH

EPS insulation resists moisture better than XPS, including on buried foundations where it is in regular contact with wetted soil.

EPS insulation resists moisture better than XPS, including on buried foundations where it is in regular contact with wetted soil.

One of the best ways to save money on rigid foam insulation installed under concrete slabs is to ensure the material is not over-engineered. A common design assumption leads to specification of rigid foam strengths that are many orders of magnitude higher than necessary, which can double the insulation material cost.

Without getting into extensive technical details and mathematical formulas, the problem is engineers often use an overly conservative approach for insulation under concrete slabs. Many designers assume that point loads applied to a slab, such as those from the wheels of a forklift, transfer to the insulation in a triangular load path. Yet, concrete slabs distribute loads more uniformly than this, which means the insulation does not need as high of a compressive resistance as when one assumes a concentrated triangular load path.

An overly conservative design approach often results in specification of a high compressive resistance XPS product, when a more cost-effective EPS would offer sufficient strength. Since XPS typically costs more per inch than EPS, this is wasted money that comes off the contractor’s bottom line.

A simple solution for contractors is to ask the designers if they are using a formula from the Theory of Plates on Elastic Foundations, which take into account how slabs and insulation behave together. A resource to point them to for example calculations is the article “Right-sizing Under-slab Insulation,” in the April 2014 issue of Structure magazine.

CONCLUSION

With building owners’ growing desire to save money on heating and cooling costs, and increasingly stringent energy codes, contractors will be installing below-grade and under-slab insulation on more of their projects. EPS insulation out-performs XPS for both long-term thermal resistance and long-term moisture absorption, and EPS comes in a variety of compressive strengths suitable for nearly all building projects. With the highest R-value per dollar, EPS is the cost effective insulation choice.

Modern Contractor Solutions Magazine, June 2014 Digital Issue

EPS QUESTIONS?

 

Ram Mayilvahanan

Ram Mayilvahanan

Contact Ram Mayilvahanan, Insulfoam’s Product-Marketing Manager

Ram.Mayilvahanan@insulfoam.com

Connect with Ram on LinkedIn  |  Follow Insulfoam on LinkedIn

Read more on Insulfoam.com

 

Project Profile: Target Retail Store Saves 25% Cost Savings in Insulation with EPS

Target  |  King of Prussia, PA  |  View Project Profile (Pdf)

R-Tech Below Grade provided 25% cost savings in insulation on the project without sacrificing performance.

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The Target store located in King of Prussia, PA was constructed different than most and was not built as a slab on grade.  The bottom level of the building is a parking garage while the retail space is located on the second level.  Target used InsulGrade R-Tech as a between slab insulation as a way of insulating the floor of the retail space and providing a thermal barrier between the concrete planks and the floor slab.

DOW XPS was initially specified on the Target project, however; R-Tech was substituted and provided a substantial cost savings while providing both long-term stable and non-degrading R-Value.

PROBLEM & SOLUTION

Space was a challenge for this Target project as the parking garage is on the ground level and the actual retail floor is on the second level.  Concrete planks were installed as the base substrate.  R-Tech was then installed over the plank to insulate the interior of the retail space from the open parking garage underneath.  A topping slab was then poured over the R-Tech to create the retail floor.  The R-Tech insulation has a long-term stable R-Value and is eligible for an Insulfoam 20-Year Thermal Performance Warranty … a warranty that’s not prorated or limited to a percentage of the published R-Value.

InsulGrade R-Tech features a premium factory-applied laminate polymeric facer that is virtually impervious to moisture, keeps water from entering the insulation, and away from concrete foundations and slabs.  Available in 4′ x 8′ panels and thicknesses starting at 3/8″, with compressive strengths from 10-50 psi.

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View Project Profile (Pdf)

PROJECT DETAILS:

EPS vs. XPS

  • Both EPS and XPS are closed-cell insulations
  • EPS and XPS below grade insulations are covered under the same standard- ASTM C578
  • EPS has a more stable R-value and less long-term moisture retention than XPS
  • XPS is 20-40% more expensive for the same compressive strength

Cost Effective

  • Highest R-value per dollar
  • 100%, 20 year R-value warranty
  • 10-30% less than XPS insulations

Green From the Start

  • Up to 20 LEED points possible
  • 100% recyclable
  • contains up to 15% recycled content
  • Minimal job site waste
  • No thermal drift
  • Helps preserve energy and fossil fuels

R-Tech Uses

R-Tech has been used successfully for numerous commercial, industrial and residential applications:

  • Below grade insulation
  • Waterproofing protection board
  • Cavity walls
  • Interior walls
  • Cold storage & freezers
  • Sheathing
  • Concrete panel insulation
  • Concrete slabs
  • Radiant heated floors

PROJECT OR EPS QUESTIONS

Jason Myers

Jason Myers, Insulfoam Territory Sales Manager

Contact Jason Myers, Insulfoam Territory Sales Manager

Cell:  609-385-8930

Email:  Jason.Myers@insulfoam.com

Connect with Jason on LinkedIn  |  Follow Insulfoam on LinkedIn

 

New Mexico Schools Save on Construction Costs with EPS Insulation

 

APS

APS Food & Nutrition Services Kitchen & Storage Warehouse, R-Tech Installation

Albuquerque Public Schools (APS) in New Mexico have been undertaking a massive classroom and educational rebuild and remodel.  All new construction has been designed using sustainable materials and energy-efficient principles with LEED certification as the end goal.

As part of new buildings under construction is a 108,000 sq. ft. central Food and Nutrition Services Kitchen and Storage Warehouse.

Originally specified XPS was replaced with Insulfoam R-Tech VI 40 psi over the sub slab freezer floor.  The project utilized 2 lifts of 3″ R-Tech instead of 3 lifts of 2″ XPS ultimately saving the  concrete contractor approximately $20,000 in material costs.

(More photos below)

Useful industry publications references on specifying EPS in below grade or under slab applications:

APS

APS Food & Nutrition Services Kitchen & Storage Warehouse, R-Tech Installation

APS

APS Food & Nutrition Services Kitchen & Storage Warehouse, R-Tech Installation

APS

APS Food & Nutrition Services Kitchen & Storage Warehouse, R-Tech Installation

PROJECT DETAILS

Questions on this project or application?

Travis Montgomery, Insulfoam Territory Manager

Travis Montgomery, Insulfoam Territory Manager

Contact Travis Montgomery, CSI, Insulfoam Territory Manager

Email: Travis.Montgomery@insulfoam.com

Connect with Travis on LinkedIn | Follow Insulfoam on LinkedIn

Read more on Insulfoam.com

 

New Below Grade Data Released: EPS vs. XPS Insulation

The EPS Industry Alliance (EPS IA) has released NEW moisture absorption data regarding XPS, moisture absorption and the effects on R-Value through the latest Technical Bulletin, EPS Below Grade Series 105:   XPS Insulation Extracted After Field Exposure Confirms High Water Absorption & Diminished R-Value, March 2014 (pdf)

EPS IA March 2014

EPS Below Grade Series 105, March 2014

A test program conducted in August 2008 evaluated the field performance of expanded (EPS) and extruded (XPS) polystyrene foam insulation in a side-by-side, below grade application following a continuous 15-year installation period.  When water and R-value retention were compared between EPS and XPS, the results demonstrated that EPS insulation outperformed XPS insulation with better R-value retention and a lower moisture absorption.

In 2013, an independent testing laboratory was again commissioned to evaluate the R-value and water absorption from XPS insulation samples extracted from several field locations and applications. A summary of the 2013 test results reconfirm there is no correlation between the results from standardized laboratory test methods and actual field exposure for XPS water absorption.  Further, the significant loss of R-value associated with XPS water absorption is shown in the summary.  

Read Full Technical Bulletin Summary (pdf)

“Studies show that as much as 25% of energy loss from a structure can be attributed to a lack of insulation. Insulation R-value is directly correlated to maximum energy efficiency in a building envelope; higher R-values translate into increased savings. It is important to understand that in-situ water absorption can diminish the thermal performance of building materials and designers must account for this when evaluating different insulation choices.”

 

Read more on the technical background expanding on the moisture resistance comparison between EPS and XPS conducted in the 2008 test program:

Insulation Choices: EPS or XPS?

Originally posted in Concrete Construction

As a specifier, architect and contractor….you must make well-informed decisions when it comes to below-grade, under slab, and cavity wall insulations in your projects.  Below are two informative articles listing the similarities and differences between both EPS (expanded polystyrene) and XPS (extruded polystyrene) insulations.

Insulation Choices:  Whether to use EPS or XPS can be a matter of cost.

Originally posted in Concrete Construction, November 2013, written by Mayilvahanan, Insulfoam’s Product-Marketing Manager

EPS insulation helps reduce heat loss through concrete foundations and floor slabs.

EPS insulation helps reduce heat loss through concrete foundations and floor slabs.

What’s the difference between XPS insulation and EPS insulation, other than a single letter? For installation on concrete foundations and under floor slabs, the rigid foam insulation you choose can make a difference of tens of thousands of dollars on a project. A careful evaluation of these materials’ performance attributes against the project’s needs can dramatically shrink labor and material costs. The savings could mean the difference between a profitable job and one you just have to chalk up to experience.

When it comes to concrete and insulation, contractors tend to be most familiar with extruded polystyrene (XPS). Yet, expanded polystyrene (EPS) performs as well or better than XPS, and at a substantially lower cost. Below are three important factors to consider when comparing these two insulations for any belowgrade or under-slab applications, read FULL article to see more side by side comparisons of EPS and EXP for these insulation factors:  1.) Compressive strength  2.) Moisture retention  3.) Insulating capability.

Full Article:  Insulation Choices

EPS vs XPS:  Insulation industry advances with EPS developments

Originally posted on Concrete Construction, February 2014, written by Frank Keisecker, ACH Foam’s VP of Sales and Marketing

There is much competition among polystyrene insulation manufacturers for the below-grade, under slab, and cavity wall insulation market. Claims made by the XPS (extruded polystyrene) industry are conflicting with that of EPS (expanded polystyrene) manufacturers. The validity of some claims is debatable. Specifiers, architects, and contractors must make well-informed decisions.

Read FULL article to thoroughly understand the similarities and differences between EPS and XPS insulations.  Key differences include: 1.) Moisture resistance 2.) Environmental impact  3.) Long-term R-value  4.) Compressive strength   5.) Panel sizes  6.) Cost per R-value.

Full Article:  EPS vs XPS

EPS QUESTIONS

Ram Mayilvahanan

Ram Mayilvahanan

Contact Ram Mayilvahanan, Insulfoam’s Product-Marketing Manager

Energy Efficient Construction at World of Concrete

EVENT:  World of Concrete, Las Vegas   |   DATE:  February 5-8th   |   BOOTH:  N2915

ABOUT INSULFOAM

The future of architecture and construction is not only going to expand and grow at a rapid pace this New Year, but it is also becoming one of the r-tech_blog copybest industries in regards to saving the environment. When it comes to ultimate respectability in the industry, two names have come together to form one truly amazing ‘gift’ for all the building-owners and contractors out there. The name, Insulfoam, is synonymous with the creation of quality polystyrene-based engineered insulation products that have become even better than before. In addition,Carlisle Construction Materials has been known in all areas of architecture and construction for single-ply roof systems and waterproofing products that are unmatched in quality, durability, and savings. With Insulfoam, the largest manufacturer of expanded polystyrene in all of North America, being a part of Carlisle Construction Materials for several years now, these two powerhouses have shown the rest of the industry that they are not only still among the most respected names in construction, but are also constantly looking out for everyone from architects to building owners to contractors. With this ‘team,’ everyone has the ability to purchase and utilize energy-efficient construction products that are a ‘must-have’ in this ‘greener’ world. Insulfoam’s products insulate buildings, from the foundation to the roof and everything in-between. Versatility is a key word when it comes to these products. Not to mention the product line is 100% recyclable. Being leaders and visionaries when it comes to new product development, the latest in technology, and code approvals, the brands of InsulFoam® and R-Tech® also contribute immensely toward LEED® credit requirements, which is one of the biggest and most important issues to address nowadays. Insulfoam products, which have warranted long-term stable R-values with no thermal loss, are built upon sustainable manufacturing practices. Dye-free, free of formaldehyde and HCFCs, no toxic chemicals or heavy metals are leeched, and prevention of mold or mildew growth, are just a few of the benefits that come with these products. Offered under the InsulFoam® and R-Tech® brands, Insulfoam’sexpanded polystyrene (EPS) products for under-slab and below-grade applications insulate foundation walls, protect water and/or damp proofing, and can be used during backfilling in both commercial and residential projects.

roofing copyStudies have shown that R-Tech® below-grade insulations have some of the lowest levels of long-term water retention among below-grade insulation products. Combined with high compressive strength and long-term stable R-values, these properties make Insulfoam’s products among the most efficient in below-grade insulation. When speaking about wall installations, Insulfoam offers a variety of insulations that cover applications ranging from exterior, interior and cavity wall applications to tongue-and-groove sheathing, whole wall, and gable end applications. Not to mention, these products are extremely lightweight and have physical properties that are well ahead of their time. But below-grade and wall installations are not all that Insulfoam is renowned for. It also makes GeoFoam, a geo-synthetic structural fill that literally exceeds the requirements of ASTM D6817 Standard Specification for Rigid Cellular Polystyrene Geofoam. This is a fantastic alternative to other fill-materials, providing excellent lateral-load support and dimensional stability as a soil and slope stabilizer in various engineered applications.  And, yes, before one asks - roofing applications are also completely covered by offering roof insulation panels that help reduce overall energy consumption, and end up creating a fantastic and comforting environment for the occupants of the building. The company has a wide-range of code-approved composite roof insulations that work with fully adhered, mechanically attached and ballasted roof systems without the need for coverboards or slip sheets. Insulfoam’s high-density composite has code approval for direct-to-combustible decks without a thermal barrier, an excellent illustration that Insulfoam products work for virtually every type of roofing system. And what’s one of the most important words to hear when it comes to building and construction products? Cost-effective! Insulfoam’s products provide some of the best R-values per dollar. These products resist almost everything, which makes these products necessary for a long list of projects ranging from highway retaining walls to parking structures to foundations, loading docks, levees, underground utility protection, railways, runways, and so much more. Are you working on an entertainment construction project that will involve theater or stadium seating? This is what you need. Working on creating that pool with deck outside? …Need I say more? Even the website that is available discussing each and every one of these products proves how efficient and up-to-date this company is. Data, research, analysis, facts, figures – even instructional and technical information is offered on each one of these products, leaving absolutely nothing to doubt. And this includes questions and data regarding global warming, RA standards and the true goal that Insulfoam and Carlisle have to decrease our ‘carbon footprint and make this a healthy place where the next generation can thrive! For more information, head to this amazing website now and get to work making that next project the absolute best and ’greenest’ it can possibly be. http://www.insulfoam.com

Cold Climate Housing Research Center uses EPS Foam to Save on Costs & Energy

Written by:  David Shong, Insulfoam Architectural & Engineering Technical Specialist

CCHRC Expansion, Alaska

CCHRC Expansion, Alaska

The Cold Climate Housing Research Center, CCHRC, in Fairbanks, AK constructed an addition to their facility in the spring of 2012.  The project Engineers specified 12″ of InsulFoam GF EPS39 which has a minimum compressive resistance of 2,160 psf @ 1% strain as a sub-base and below slab insulation.  EPS39 was placed around the perimeter under the exterior wall footings and within the zones of influence of interior columns that required higher bearing capacity to withstand the axial loads of the walls,roof and snow load.

The rest of the areas that were simply supporting the 6″ floor slab used 12″ of EPS22 (1051 psf @ 1% strain).  They were originally considering only 9″ of EPS46 (2,678 psf @ 1% strain) for the entire building footprint, but were happily surprised to hear the idea of using a lower density under the floor slabs where the decreased dead loads justified a lower EPS density.

They ended up being able to install 12″ of EPS under the entire footprint for less than the original budget which provided more insulation while saving on initial costs as well as long term energy expenditures.

CCHRC Expansion, Alaska

CCHRC Expansion, Alaska

CCHRC Expansion, Alaska

CCHRC Expansion, Alaska

Insulation Solutions at Greenbuild

Greenbuild 2012 We are in full swing with final preparations for Greenbuild 2012 in San Francisco Nov 14-16, the largest international conference and expo dedicated to green building.  With 35,000 participants expected this will be one of the largest Greenbuild shows ever.  Exciting!

1,000+ exhibitors, how do you decide what booth to go to, who to talk to?  Ok, we aren’t Kohler who seems to have one of the BEST booths possible every year (and the one booth I always make sure to sneak away and visit), but  we do have plenty of good information to help you with your next insulation project and meet your energy efficiency goals.  Insulfoam (booth #3169N) provides insulation solutions from roof to foundation and everything in between.

High Performance.  Lower Cost.  Most R-Value Per Dollar.

With a broad range of insulation products available, it’s easier than ever for designers to create an energy efficient building project.  InsulFoam EPS (Expanded Polystyrene) rigid foam insulation has been used for decades by smart industry professionals looking to achieve high thermal properties for a cost-effective price.  In fact, EPS offers more cost savings and higher R-Values than any other rigid insulation.  The benefit of lightweight EPS goes far beyond price, since it also helps contractors significantly decrease material and labor expenses.  EPS is also one of the most versatile engineered insulations, making it a designer’s dream product.  You tell us what you need and we make it fit within your design.  Not limited by stock sizes InsulFoam blocks can be molded, cut, shaped, tapered into virtually any design need, regularly solving challenges for contractors on the jobsite.

InsulFoam EPS is the only rigid insulation that does not experience “thermal drift” (loss of R-Value over time).  In fact, the R-Value is backed with a 20-year non-prorated thermal performance warranty.  ISO and XPS rigid insulations don’t come close in warranty, so you can be confident that Insulfoam’s EPS products are the best rigid insulation option for your project.

The following Insulfoam product lines will be highlighted in our Greenbuild booth with specialists to talk you through technical attributes  applications, projects and more.  And not to mention we got some pretty great and easy to talk to guys!  As you gear up for planning mode this coming week, put Insulfoam’s booth #3169N on your route.

Premier SIPs by Insulfoam

FRAMING SYSTEMS:  Premier SIPs by Insulfoam:  Structural Insulated Panels are an extremely strong building panel that need no additional frame of skeleton for support.  Premier’s large, pre-fabricated SIPs make the framing process faster than other building methods and enable a more airtight, well-insulated building for high energy efficiency.

Insulfoam Below Grade Insulation

BELOW GRADE INSULATION:  Insulfoam’s Below Grade Insulation products are designed to insulate the foundation wall or slab and protect the waterproofing or damp proofing, especially during backfilling for both commercial and residential below-grade applications.  Compressive strength, moisture protection and thermal stability.

ROOF INSULATION SOLUTIONS:  Insulfoam’s roofing insulation applications are green, high-performing and economical products that help reduce overall energy consumption, create improved comfort for the building’s occupants and provide an excellent substrate for a new or retrofit roofing system.

Insulfoam Roof Insulation Solutions

INSULFOAM GEOFOAM:  InsulFoam GF provides structural and architectural void fill  applications that are lighter, easier to handle and faster than soil.  Hardscapes, landscapes, soil remediation and load reduction.

Insulfoam Geofoam

For real time updates before, during and after the expo follow us on Twitter:  @PremierSips @Insulfoam @InsulFoamGF.  Be sure to also check out Greenbuild’s official twitter feed, @Greenbuild and conversation at #Greenbuild.

For more event information:  Greenbuild Schedule  |  Greenbuild Expo Tools & Map