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Enter CSPE• Chlorosulphonated

Polyethylene (akaHypalon) came to therescue for roofsexposed to atmosphericpollution.

• Like EPDM, joints in itcould be solvent welded

• Like PVC, joints in itcould be heat welded

• Unlike both, it had to bereinforced with afiberglass mesh (scrim)to prevent tearing.

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Heat weldingseams

Not a good day to be a roofer.

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What’s wrong with thispicture?

What’s wrong with thispicture?

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Flamethrower not included

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The landscape of low sloperoofing today

• BUR• PVC• EPDM• CSPE• Spray applied membranes• Modified Bitumen's

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Most common low-slope

B.U.R Built-up Roof $204/square

Modified Bitumen $190/square

E.P.D.M Ethylene PropyleneDiene Monomer

$173/square – adhered$127/square - fastened$121/square – ballasted

P.V.C. Polyvinyl Chloride $200/square – adhered$147/square - fastened$140/square – ballasted

C.S.P.E. ChlorosulfonatedPolyethylene - Hypalon

$208/square – adhered$192/square - fastened$180/square – ballasted

*R.S. Means 2003

Modified Bitumen…(cleanerbitumen?)

• The single-ply’s took a significantpercentage of the market share BURused to hold.

• The BUR industry’s response was todevelop it’s own single ply membrane.The modified bitumen membrane is athick layer of a highly plasticizedbitumen, often reinforced with apolyester grid (scrim)

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Modified Bitumen

• The modified bitumenmembrane came in 48”wide rolls so it has morejoints than many of theother single ply’s.

• But the modifiedbitumen system isjoined at the overlap byheating with an openflame, then rolling thesoftened membrane toseal the joint.

• flamethrower

Mod. Bit. advantages

• Compatibility withBUR.– Projects requiring additions

be connected to existingBUR’s in good condition areprime contenders for modifiedbitumen membranes – theycome from the samematerials family

– Many modified bitumenmembranes are availablewith a granular aggregate(like roof shingles) embeddedin the surface. This makescolor available (white reallycuts A/C costs!) and providessome UV protection andsome protection fromphysical abrasion

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