Post on 09-Apr-2022
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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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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