BLUEPRINTS*

Services

Insulation for GeotechnicalApplications

*Trademark of The Dow Chemical Company

2 *Trademark of The Dow Chemical Company

STYROFOAMHigh Load*

Throughout those regionswhere underlying soils are proneto frost action, highways, railways,building foundations, even buriedutilities run the risk of damagefrom frost heaving and springbreak-up.

Soil insulation is a means ofprotecting in-ground constructionfrom the ravages of frost action.The concept itself is borne of theinsulating principles common tothe design of buildings aboveground.

Above or below ground, thegoal is to control the transfer ofheat from one area to anotherwith insulation. To this end, DowChemical Canada Inc. conceivedand developed STYROFOAMHigh Load, a versatile CAN/CGSB51.20-M87 TYPE 4 extruded polystyrene rigid board insulation.

By placing a layer of STYROFOAM High Load insulationin the upper level of the soil, itsunique combination of propertieswill effectively prevent harmfulsub-soil frost action. Since 1962,STYROFOAM High Load hasbeen used in engineering con-struction in Canada, the U.S.A.,Japan and throughout Europe.On roadways, rail lines, airportpavements, culverts, building andtransmission tower foundations,drainage works and in-groundutilities, STYROFOAM High Loadhas proven to be an economical,long term solution to ground frostproblems.

STYROFOAM HIGH LOAD FOR SOIL INSULATION

In seasonal zones, STYROFOAMHigh Load insulation conservesthe natural heat in the subgrade,retarding frost penetration duringwinter and, in turn, eliminatingfrost heave and spring break-up.

In permafrost zones, STYROFOAM High Load performsthe inverse task of retaining thefrozen state of the subgradeduring summer months to preventa warming influence in the sub-grade which would result inthaw-weakening.

FROST HEAVE

STYROFOAM High Load curtails heat loss from the subgrade. Frost penetration is reduced, preventing ice lenses from forming, which would normally result in frost heaving.

SPRING BREAK-UP (THAW-WEAKENING)

STYROFOAM High Load prevents the freezing of lower soilzones which would impede drainage and result in springbreak-up. Where load-bearing capacity is important, anembankment with drainage ditches should be provided.

PERMAFROST THAW (SUMMER MONTHS)

STYROFOAM High Load prevents the thawing of permafrostduring summer to retain the load-bearing capacity of thefrozen subgrade.

FROST-SUSCEPTIBLESOIL

GROUND SURFACE

GOOD DRAININGNON-FROSTSUSCEPTIBLE SOIL

STYROFOAM HIGHLOAD INSULATION

GROUND SURFACE

GROUND SURFACERETURNS TO ORIGINALPOSITION WHEN ICELENSES MELT

GOOD DRAINING SOILHERE IS IMPORTANT

STYROFOAM HIGH LOADINSULATION

ICE LENSES

FROST-SUSCEPTIBLESOIL

GROUND SURFACE

GOOD DRAININGSOIL

STYROFOAM HIGH LOADINSULATION

PERMAFROST TABLE(SUMMER)

ICE LENSES

UNINSULATED SOIL

UPWARD PRESSURE

INSULATED SOIL

FRO

ST P

EN

ETR

ATIO

N

FROSTFRONT

WATER TABLE

STYROFOAM HIGH LOADINSULATION PREVENTSFREEZING OF SOIL

UNINSULATED SOIL INSULATED SOIL

FRO

ZEN

SO

IL

WATER TABLE

SOME WATER WILL PENETRATETHE INSULATION JOINTS ANDPASS THROUGH THE UNFROZENSOIL TO THE WATER TABLE

UNINSULATED SOIL INSULATED SOIL

WATER

MOISTURE MIGRATIONTO FROST FRONT

RAIN AND MELT WATERSUPERSATURATE THEUPPER SOIL. SOIL BEARINGCAPACITY IS REDUCED.

FROZEN SUBGRADEBLOCKS THE PASSAGEOF WATER TO THEWATER TABLE.

THAWEDSOIL

FROST HEAVE

PERMAFROST UNDERTHE INSULATED AREAREMAINS FROZENYEAR-ROUND

MELTED PERMAFROSTIN SUMMER, SUPERSATURATESTHE SOIL CAUSING“THAW WEAKENING” CONDITIONS

3

INSULATED PAVEMENTSAND RAIL LINES

For over 30 years, countlessnumbers of engineers have foundthat STYROFOAM High Loadinsulation is an ideal defenceagainst the damage wrought byfrost heave and spring break-upon projects including roadways,airport runways and rail lines.

Over the course of these manyyears, a number of test siteshave been monitored to checkthe stability of STYROFOAMHigh Load. The assembled datashows no signs of frost heaveor spring break- up. Samples ofSTYROFOAM High Load whichhave been recovered from varioushighway installations also showvery little increase in water pick-up, little loss of thermalresistance, and in all casesthe structural integrity of theinsulation was retained.

TYPICAL INSULATED AIRPORT RUNWAYIn comparison to highways, airportrunways are much wider and normally require a greater thick-ness of pavement. However, the same insulation principles apply as in insulated highways.

TYPICAL INSULATED RAIL LINEThe principle used in the design of railroad insulation is the same as the one used in highway and airport pavements. Consequently STYROFOAM High Load insulation should extend well into the embankment to provide adequatefrost protection from the flanks.

DOJ

TYPICAL INSULATEDHIGHWAY

CONCRETE ORASPHALT PAVEMENT

GRANULAR EMBANKMENT

STYROFOAM HIGH LOAD INSULATION

DITCH

FROST FRONT

WATER TABLE

FROST-SUSCEPTIBLE SOIL

RUNWAY PAVEMENTGRANULAR EMBANKMENTSTYROFOAM HIGH LOADINSULATION

FROST FRONT

DITCH

WATER TABLE

FROST-SUSCEPTIBLE SOIL

TIES

GRANULAR EMBANKMENT

STYROFOAM HIGH LOAD INSULATION

GRADE

FROST FRONT

WATER TABLE

FROST-SUSCEPTIBLE SOIL

TYPICAL BRIDGE APPROACH

SECTION THROUGH HIGHWAY BRIDGE APPROACH EMBANKMENT

4

INSTALLATION STYROFOAM High Load insulationis laid over the prepared subgradeusing conventional road buildingequipment and techniques. Inareas where wind blow-off isa problem, the insulation canbe pinned down with woodenskewers, weighed down withgranular material, or if appliedover old pavement, it can be stuckdown with an asphalt emulsionadhesive tack coat. The first liftof granular material should becarefully placed and compacted toprevent damage or displacementof the insulation. Subsequent liftsand asphalt or concrete pavingsurfaces are then applied in theusual manner.

For more information, a “Highway Insulation” brochurecan be obtained from any DowChemical Canada Inc. office.

LIGHTWEIGHT FILL USING STYROFOAMHIGH LOAD INSULATION

In the design and construc-tion of embankments or retainingwalls requiring great depths offill, unstable soils and settlementcan pose grave problems. In thesecases, special backfill materialsand methods are necessary whendealing with problems over weak subgrades.

STYROFOAM High Load weighsless than 48 kg/m3 (3 lbs./cu.ft.)compared with conventionalbackfill at 1800 to 2100 kg/m3

(110-130 lbs./cu.ft.). That’s aweight reduction of approximately97%. Where no live loads areinvolved, the size and strengthof retaining walls can be reducedgreatly.

On a cautionary note, whenusing STYROFOAM High Loadas a lightweight fill, it shouldhave a cover of granular fill andpolyethylene sheet to protectit from sunlight, physicaldamage, floatation and spillsof incompatible chemicals.

PAVEMENT

GRANULAR BACKFILL

POLYETHYLENE FILM

STYROFOAM HIGH LOADINSULATION LIGHTWEIGHT FILL

WEAK SUBSOIL

5

RIGID TOWERFOUNDATION

INSULATED TRANSMISSION TOWERFOUNDATIONS

The placement of STYROFOAM High Load in tower foundation areas can drasticallyreduce or eliminate heave andfreezing forces which can resultin bent and broken tower diagonalbracing. STYROFOAM High Loadreduces the depth of frost pene-tration during the freezing seasonand therefore reduces the risk ofdamaging frost action. In perma-frost zones, a pad of insulationover the tower base and aroundthe foundation posts will preventthawing during the summer andpreserve a structurally soundsubgrade year-round.

STYROFOAM HIGH LOADAND BURIED UTILITIES

Conventional construction ofburied water and sewer lines callsfor placement below the frostline. This can sometimes meandeep excavation, rock cutting,even pumping stations. Whereexcavation is difficult and expen-sive, there is a cost-efficientalternative. Utility lines can beinsulated with STYROFOAMHigh Load and placed closer tothe surface. This technique canbe used not only for new lines butalso current ones where regrad-ing would reduce the existingprotective frost cover.

GUYED TOWER FOUNDATION

CONCRETEFOUNDATION

BACKFILLSTYROFOAM

HIGH LOAD INSULATIONINSULATED FOUNDATION

ANCHORSFROST-SUSCEPTIBLE

SOIL

TOWERSTRUCTURE

GRANULAREMBANKMENT

STYROFOAM HIGH LOAD INSULATION

FROST-SUSCEPTIBLE SOIL

6

DESIGN PROCEDURE

The Horizontal Insulated UtilityLine method is widely used andgives satisfactory results if correctconstruction procedures are followed.

The inverted U Insulated Utility Line method can be usedwhere the design width of hori-zontal layer is greater than allowedin the field. With the inverted Uconcept, the insulation widthrequired is reduced by the intro-duction of two vertical legs. The

dimensions of the two verticallegs and the top horizontal layerof insulation should be summedto give the total width of insulation(W) as shown below. The bottomof the vertical legs should belevel with the bottom of the line.Table 1 can be used to determinethe thickness of insulation neededto protect a utility line based ondepth of cover and geography.

INSTALLATIONUsing STYROFOAM High Load

won’t alter conventional line con-struction methods. However, insome cases a wider trench maybe needed to accommodate the horizontal layer of insulation.

HORIZONTAL LAYER

INVERTED U

WIDTH OF INSULATION: W = 3D + 2[F – (X + D + 0.5)] For imperial calculationW = D + 2(F – X) – 0.3 For metric calculation

WHERE W = WIDTH OF INSULATION (METERS) (FT)D = PIPE DIAMETER (METERS) (FT)X = INSULATION DEPTH (METERS) (FT)F = ESTIMATED FROST DEPTH (METERS (FT)

SURFACE

BACKFILL(MINIMUM 0.4m) (1'- 4")

STYROFOAM HIGH LOAD-40INSULATION

GRANULARMATERIAL

ESTIMATEDFROST DEPTH

GROUNDLEVEL

BACKFILL(MINIMUM 0.4m) (1'- 4")

STYROFOAM HIGH LOAD-40INSULATION

GRANULARMATERIAL

VERTICAL LEG

0.15m (6”)

0.15m (6”)

XW

FD

TABLE 1: THICKNESS OF STYROFOAM HIGH LOAD BRAND INSULATION THICKNESS OF INSULATION IN MM AND INCHES

Design Freezing Index (°C-Days)

850 1125 1400 1675 1950 2225 2500

0.6 50.0 65.0 75.0 90.0 100.0 115.0 125.0

0.9 40.0 50.0 65.0 75.0 90.0 100.0 115.0

1.2 25.0 40.0 50.0 65.0 75.0 90.0 100.0

1.5 25.0 25.0 40.0 50.0 65.0 75.0 90.0

1.8 25.0 25.0 25.0 40.0 50.0 65.0 75.0

2.1 25.0 25.0 40.0 50.0 65.0

2.4 25.0 25.0 40.0 50.0

2.7 25.0 25.0 40.0

3.0 25.0 25.0

7

EXISTING LINESCentered over the length of

the line, dig a trench 0.15 meters(6") above the top of the line.Remove large lumps of soil to ensure the trench bottom issmooth and place the insulationboards on this base, buttedclosely together. Where theinverted U method is used, thebottom of the vertical legs shouldbe level with the bottom of theline. With bedding material hold-ing the legs in place, place thehorizontal layer of insulation ontop of the legs after the line hasbeen covered with 0.15 meters(6") of bedding.

NEW LINESGranular material is compacted

to provide 0.15 meters (6") pro-tective cover for the line. Insulationis then laid to a pre-determinedwidth and butted together. Normalbackfill operations are then carried out. If the inverted Umethod is used, place the verticallegs along the walls of the trench,using bedding material to holdthe legs in place. Compact thebedding material to provide 0.15 meters (6") cover for theline. Place the horizontal layer ofinsulation on this and backfill.Care should be taken to preventvehicles and heavy equipmentfrom bearing directly on the

insulation. A minimum 0.20 to0.25 meters (8" - 10") of compactedlift is required before any heavytraffic passes over the insulation.

INSULATION OF UTILITIES IN ROCK

In solid rock, frost penetrateseasily due to the rock’s highthermal conductivity andabsence of any appreciableamount of water. Since there islittle or no available heat fromthe ground and pipelines in rockmust be insulated from freezing,these lines should be insulatedfrom top to bottom and on allsides.

Am

ount

of B

ackf

ill o

ver

the

Insu

latio

n (m

)

Design Freezing Index (°F-Days)

1500 2000 2500 3000 3500 4000 4500

2'-0" 2.0" 2.5" 3.0" 3.5" 4.0" 4.5" 5.0"

3'-0" 1.5" 2.0" 2.5" 3.0" 3.5" 4.0" 4.5"

4'-0" 1.0" 1.5" 2.0" 2.5" 3.0" 3.5" 4.0"

5'-0" 1.0" 1.0" 1.5" 2.0" 2.5" 3.0" 3.5"

6'-0" 1.0" 1.0" 1.0" 1.5" 2.0" 2.5" 3.0"

7'-0" 1.0" 1.0" 1.5" 2.0" 2.5"

8'-0" 1.0" 1.0" 1.5" 2.0"

9'-0" 1.0" 1.0" 1.5"

10'-0" 1.0" 1.0"

Am

ount

of B

ackf

ill o

ver

the

Insu

latio

n (f

eet)

WIDE PIPE TRENCH IN ROCK

Max. freezing index °C-Days(Max. freezing Index °F-Days)

8

DESIGN PROCEDUREThe insulation nomograms➀

below show the required insula-tion thickness for narrow and widepipe trenches and the heat supplyneeded from the line itself orfrom an electric heating cable. A wide trench in rock means thatthe covering ground layer on therock is so thin that the rock iswithin the expected frost depth,resulting in a freezing of the line

from below. For a narrow pipetrench in rock, the laying depthdoesn’t have a major effect onthe needed heat supply becauseof the proximity of the trenchside slopes. When using the insulation nomograms, note thatthe required heat supply will bereduced for a given insulationthickness when the total widthand height of the insulation isminimized.

➀ GUNDERSON, P., “FROST PENETRATION OF BURIED WATERAND SEWAGE PIPES; THREE ARTICLES,”NORWEGIAN BUILDING RESEARCH INSTITUTE, OSLO.

0

2

4

6

8

10

12

14

16

Hea

t sup

ply

requ

ired

W/m

2500 2080 1660 1240 820 400(4500) (3700) (3000) (2200) (1475) (700)

50mm STYROFOAM insulation

(2") thickness

75mm(3")

100mm(4")

150mm(6")

Insu

latio

n w

idth

(b),

m: 0

.4

(16"

)

0.6

(24"

) 0.8

(32"

)1.0

(40")

1.2

(48")

Insulation height (h), m: 0.4 (16")

0.5 (20")

0.6 (24")

0.7 (28")

NARROW PIPE TRENCH IN ROCK

Max. freezing index °C-Days(Max. freezing Index °F-Days)

0

2

4

6

8

10

12

14

16

Hea

t sup

ply

requ

ired

W/m

2500 2080 1660 1240 820 400(4500) (3700) (3000) (2200) (1475) (700)

50mm STYROFOAM insulation

(2") thickness

75mm(3")

100mm(4")

150mm(6")

Insu

latio

n w

idth

(b),

m: 0

.4

(16"

)

0.6

(24"

) 0.8

(32"

)1.0

(40")

1.2

(48")

Insulation height (h), m: 0.4 (16")

0.5 (20")

0.6 (24")

0.7 (28")

9

INSULATED BUILDING FOUNDATIONS

The concept of insulated shallow foundations allows theplacement of insulation in a con-figuration that will reduce frostpenetration. This also allows fora corresponding reduction infoundation depth resulting in costsavings in excavating, backfilling,foundation materials and reducedperimeter heat losses. As shownin the diagrams below, the insulated foundation concept differs between heated andunheated buildings. In addition to reducing frost penetration,STYROFOAM High Load reduceshigh thermal gradients beneaththe footings which minimizesmoisture migration and reducesthe effect of soil shrinkage.

DESIGN DATADesign criteria have been

published by E.I. Robinsky andK.E. Bespflug, Journal of the Soil Mechanics and FoundationsDivision, Proceedings of theAmerican Society of Civil Engineers, Volume 99 NOSM9,September 1973, Pages 649-667.Four of their nomograms are reproduced on the following pages.

HEATED BUILDINGIn heated structures, the STYROFOAM High Load insulation is laid in the configuration asshown, around the perimeterof the building to protect the footing from frost damage.The depth of this footing is governed by the requiredload-bearing capacity of thesoil, not the frost penetration.

UNHEATED BUILDINGIn unheated structures,a continuous STYROFOAMHigh Load insulation pad mustbe provided beneath the entire area of the floor, footings and beyond as required to adequately protect against frost. In permafrost regions, the use of insulation permits a considerable reduction in the thickness of granular fill.

WALL

GRADE

GRANULAR FILL

STYROFOAM HIGH LOAD INSULATION

FOOTING

WALL

GRADE

FLOOR SLABAND GRADE BEAM

STYROFOAM HIGH LOAD INSULATION

FROST-SUSCEPTIBLE SOIL

FROST FRONT

MINIMUM OF300mm (12”)BELOW GRADE

FRO

ST P

EN

ETR

ATIO

NFR

OST

PE

NE

TRAT

ION

MINIMUM OF300mm (12”)BELOW GRADE

FROST FRONT

MINIMUM OF600mm (24”)BELOW GRADE

FROST-SUSCEPTIBLE SOIL

10

SHALLOW FOUNDATIONDESIGN NOMOGRAMS

When considering an insulatedshallow foundation, it’s impor-tant to take soil-bearing capacityinto consideration as it maycall for a deeper excavation. STYROFOAM High Load, withits high compressive strength, is

an ideal choice for this applicationas it can sustain very high loading.

For heated buildings, it is recommended to increase thethickness of the STYROFOAMHigh Load at the corners of thebuilding to 1-1/2 times the chosen

Generalized Design Curves for Minimum

Insulation Requirements for Heated Structures

on Clayey or Silty Soil with Insulation Extending to 1 ft.

(300 mm) Above Grade

Generalized Design Curves of Minimum

Insulation Requirements for Heated Structures

on Sandy Soil with Insulation Extending

to 1 ft. (300 mm) Above Grade

Freezing Index, (F. Degree-Days)Soil Conditions: dry density = 85 pcf (1362 kg/m3), water content = 30%

all soil water freezes at 32°F (273°K)

Freezing Index, (F. Degree-Days)Soil Conditions: dry density = 105 pcf (1681 kg/m3), water content = 10%

all soil water freezes at 32°F (273°K)

11

thickness, t. The thicker insula-tion should extend back fromthe corners along the walls and grade beam a distance equal to the chosen width of the perimeterinsulation slab, L.

It is recommended that theperimeter insulation strip beplaced on a slight slope, gradingaway from the structure toencourage drainage.

Design Curve for Foundation Insulation of Unheated Structures on Clayey or Silty Soil; Assumptions: Dry Density 85 PCF (1,361 kg/m3), Water Content 30%; All Soil Water Freezes at 32°F (273°K)

Design Curve for Foundation Insulation of Unheated Structures on Sandy Soil; Assumptions: Dry Density 105 PCF (1,681 kg/m3), Water Content 10%; All Soil Water Freezes at 32°F (273°K)

Freezing Index, (F. Degree-Days)

Freezing Index, (F. Degree-Days)

12

STYROFOAMHIGH LOAD FORICE RINKS

Due to its high compressivestrength, high resistance to waterabsorption and tolerance to soilconditions, STYROFOAM High Loadis ideal for installation below rinkfloors. Insulating with STYROFOAMHigh Load is recommended forthese reasons:

1 to raise the frost line above the level of soils susceptible to frost heaving in rinks which operate seasonally.

2 to reduce the initial and long-term operating costs of soil heating equipment in rinks which operate continuously.

3 to reduce ice-making time.

4 to reduce the required capacity of refrigeration equipment.

SOIL CONDITIONIf practical, the ice rink should

be located on a site where the soil is not susceptible to frost heaving. If this isn’t possible, the site should be prepared in the following manner. Remove the upper layer of frost-susceptible soilto a minimum depth of 300 mm (1 ft.). Replace this witha compacted, free draining, non-frost-susceptible material which will provide proper drainage and eliminate frost heaving. If the insulation is to be placed directly

on this base material, the basematerial should be compactedand leveled as specified by anengineer, and any large stoneswhich might damage the insula-tion removed.

SEASONAL VS. CONTINUOUS USE

If the rink has a seasonal operation requirement, the designrelies on a warm summer cycleto melt any frost that may haveaccumulated below grade. If therink has been designed for con-tinuous operation, the insulationwill NOT prevent the freezing ofthe subgrade. A soil heatingdevice can resolve this. In thiscase, the insulation acts as aseparator between the heatingand refrigeration equipment.

APPLICATIONThe insulation is placed below

the refrigerated slab or sandlayer and should extend 900 mmto 1200 mm (3 ft-4 ft) beyondthe edges of the refrigerated layer.The insulation is usually appliedover the compacted base mate-rial or a concrete sub-slab.

STYROFOAM High Load brand insulation ThicknessRequired for Seasonally Operated Rinks

Months of OperationIce

Temperature 5-6 7-8 9-10

-6°C 50 mm 60 mm 75 mm(22°F) (2") (21⁄2") (3")

-9°C 60 mm 75 mm Design for(16°F) (21⁄2") (3") continuous

operation

STYROFOAM High Load brand insulation ThicknessRequired for Continuously Operated Rinks.

ELECTRIC HEATING SYSTEMS– high cost power areas 75 mm (3")– low cost power areas 50 mm (2")

FUEL FIRED HEATING SYSTEMS(unless fuel costs are unusually high) 50 mm (2")

Note: Use 300 mm (1 ft.) of non-frost-susceptible fill under the insulation.

Note: In view of the possibility of high energy costs in the future, consideration should be given toincreasing the thickness of the insulation.

13

FEATURES STYROFOAM High Load insulationhas a range of propertieswhich makes it suitable forsoil applications.

1 EXCELLENT INSULATINGCHARACTERISTICS: possessesone of the highest thermal resistance (RSI) (R) values whencompared with other insulations.

2 VERY LOW WATER ABSORPTION: applications where the insulation is used belowground (e.g., under highways)present severe conditions whichinclude high soil humidities, long-term exposure to water andfreeze-thaw cycles. Under theseconditions most insulating materials are subject to waterabsorption, physical break- down and loss of insulating properties. Due to its low waterabsorption and high strength,STYROFOAM High Load insulationis virtually unaffected and retainsits insulating value as evidencedby samples of STYROFOAM HighLoad removed from highwayinstallations after as long as 14years in the ground.

3 HIGH COMPRESSIVESTRENGTH: good durability andresistance to damage. Threecompressive strengths to choosefrom: High Load-40, High Load-60and High Load-100. Refer toproperties table for information.

4 UNIFORM CONSISTENCY:the extrusion and foam manu-facturing process producesboards of consistent thickness,density, strength, thermal andmoisture resistance, etc.

5 UNIQUELY SUITED FOR IN-GROUND APPLICATION:withstands repeated freeze/thawcycling without physical de-gradation such as crumbling orwaterlogging. Will not sustainmould or decay.

6 PROVEN PERFORMANCE:monitoring of installations since 1962 verifies that

STYROFOAM High Load insulationhas the properties necessary forlong-term performance in soilinsulation applications.

7 CUTS EASILY: and is non-irritating and non-toxic.

8 STANDARDS ANDACCEPTANCES: STYROFOAMHigh Load insulation meets orexceeds the requirementsof CGSB SpecificationCAN/CGSB-51.20-M87(Type 4).

14

PRECAUTIONS 1 STYROFOAM High Load insu-lation must be protected againstexposure to sunlight, physical damage, and incompatible chemicals (solvents, petroleumproducts, etc.) that might seepinto the ground from accidentalspills. Where flooding or highwater table may submerge theinsulation, the overlying backfillmust provide sufficient ballastto prevent floatation. These protective measures usually areattained with a cover of granularfill and a layer of polyethylenesheet.

2 To avoid surface degradation,do not leave STYROFOAMHigh Load insulation exposed todirect sunlight for long periods oftime. Cover insulation temporarilystored on the jobsite with alight-colored tarpaulin.

3 BURNING CHARACTERISTICS:although STYROFOAM High Loadbrand insulation contains a flameretardant agent to inhibit acci-dental ignition from a small firesource, it will burn and onceignited may burn rapidly releasingdense smoke. STYROFOAMHigh Load insulation must not beexposed to an open flame orother ignition source.

4 DIFFERENTIAL ICING: whenSTYROFOAM High Load insulationis placed in the ground, under ahighway or paved area, it actsto prevent or diminish freezing ofthe subgrade in seasonal areas,or thawing in regions of perma-frost. Since the insulated sectionhas a different thermal regimethan the adjacent non-insulatedsection, different surface tem-peratures can result between thetwo. Under certain conditions,the difference in temperaturebetween sections can be sufficientto allow one surface to supportthe formation of ice while theadjacent surface does not. Thisdiscontinuous or “differential”icing phenomenon also occursover conventional non-insulatedpavement sections in practicallyall areas subject to freezing andthawing conditions. Frequency

of occurrence is dependent primarily on meteorological conditions and the thermal properties of the highway section.

Precautions should be takenby the design authority to mini-mize the consequences of dif-ferential icing. Studies have foundthat differential icing can be minimized by either lowering theinsulation in the pavement section,or by putting in thinner sectionsof insulation. We strongly recom-mend that insulated sectionsshould not be started: i) in themiddle of a curved portion ofroad; ii) at the top of a hill; iii) neara major intersection; or iv) near a railway crossing. See Dow publication “Highway Insulation”.

5 LONG-TERM CREEP ANDFATIGUE: Like all building materials, designers must useadequate safety factors to limitlong-term deformations whenloading STYROFOAM High Load insulation. See Dow publication“Highway Insulation”.

Property High Load-40 High Load-60 High Load-100

Compressive Strength➀ (min) 275kPa 415kPa 690kPaASTM D1621-73 (40 psi) (60 psi) (100 psi)

Tensile Strength (Typical) 480kPa 590kPa 860kPaASTM D1623-78 (Method A) (70 psi) (85 psi) (125 psi)

Shear Strength (Typical) 275kPa 310kPa 350kPaASTM C273-61 (40 psi) (45 psi) (50 psi)

CGSB Classification Can/CGSB – 51.20 – M87 (Type 4)

Flexural Strength➁ (Typical) 480kPa 585kPa 585kPaASTM C203-91 (70 psi) (85 psi) (85 psi)

Compressive Modulus (Typical) 965OkPa 1517OkPa 2551OkPaASTM D1621-73 (1400 psi) (2200 psi) (3700 psi)

15

SPECIFICATIONS

PROPERTY METRIC IMPERIAL

†Thermal resistance. Typical 5 year aged 0.87 (m2°C)/W 5.0 ft2hr°F/BTUR-value or RSI➀ ASTM C-518-91, C-177-85

Linear thermal coefficient of 6.3 x 10-2 mm/m/°C 3.5 x 10-5 in/in/°Fexpansion ASTM D696-79

Capillarity NONE NONE

Water vapor permeance➀ (max) 35 ng/Pa s m2 0.6 permsASTM E96-90

Water absorption (% by volume) less than 0.7 less than 0.7(max) ASTM D2842-90

Maximum operating temperature 74°C 165°F

NOTE: ➀ At 5% deformation or yield, whichever comes first.

Suitable safety factors must be employed to limit long-term creep and fatigue deformations.

➁ For 25 mm or 1 inch thickness.

NOTE: ➀ For 25 mm or 1 inch thickness.† Based on a sample 11⁄2" thick, the typical R-value

(28 days at 70°C) = 5.2 (ft2 hr°F/BTU-inch) [RSI = 0.92 (m2°C/W-25.4 mm)]

PRECAUTIONS: This product is combustible and should be properly installed. For specific instructions see Dow literature available from your supplier or from Dow.

NOTICE: No freedom from any patent owned by Seller or othersis to be inferred. Because use conditions and applicable lawsmay differ from one location to another and may change withtime, Customer is responsible for determining whether productsand the information in this document are appropriate forCustomer’s use and for ensuring that Customer’s workplace anddisposal practices are in compliance with applicable laws andother government enactments. Dow Seller assumes no obligationor liability for the information in this document. NO WARRANTIESARE GIVEN; ALL IMPLIED WARRANTIES OF MERCHANTABILITYOR FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLYEXCLUDED.

Warning: STYROFOAM brand insulation products are combustibleand may constitute a fire hazard if improperly used or installed.Consult Dow for further information. The material contains aflame retardant additive to inhibit accidental ignition from smallfire sources. During shipping, storage, installation and use, theseproducts should not be exposed to open flame or other ignitionsources.

Printed in U.S.A.*Trademark of The Dow Chemical Company DCN542-398BWW

McKAY144038

Dow Chemical Canada Inc.Construction Materials

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