To obtain a copy of a specific publication, users should contact the publication's publisher directly.
Abstract
During the past decade, the occurance of membrane slippage in bituminous built-up roofing has become of increasing concern to the roofing industry. While a number of factors, such as bitumen properties, felts, slope of roof deck, climate, substrate and surface of the roof, often contribute - usually in concert - to slippage problems, in many slippage complaints, the properties of the bitumen, such as consistency and temperature susceptibility, appear to be the main contributors toward this type of failure. Further, overheating of certain asphalts in the absence of air can result in "softeneing point fall back" of the asphalts, which makes roofs constructed from them more vulnerable to slippage. In the project, the effects of bitumen properties(asphalt and coal-tar pitch, interply bitumen film thickness, types of felt, slope of deck, and surface loading) on the vulnerability of two-ply membranes were studied. For these purposes, a simple viscometer and laboratory sag and slippage test methods were developed. These tests were performed at temperatures a roof would normally reach on warm summer days. This report gives the results of the laboratory research as well as field observations of membrane slippage in service. Further, causes of slippage are discussed and suggestions made to reduce the incidence of slippage.
During the past decade, the occurance of membrane slippage in bituminous built-up roofing has become of increasing concern to the roofing industry. While a number of factors, such as bitumen properties, felts, slope of roof deck, climate, substrate and surface of the roof, often contribute - usually in concert - to slippage problems, in many slippage complaints, the properties of the bitumen, such as consistency and temperature susceptibility, appear to be the main contributors toward this type of failure. Further, overheating of certain asphalts in the absence of air can result in "softeneing point fall back" of the asphalts, which makes roofs constructed from them more vulnerable to slippage. In the project, the effects of bitumen properties(asphalt and coal-tar pitch, interply bitumen film thickness, types of felt, slope of deck, and surface loading) on the vulnerability of two-ply membranes were studied. For these purposes, a simple viscometer and laboratory sag and slippage test methods were developed. These tests were performed at temperatures a roof would normally reach on warm summer days. This report gives the results of the laboratory research as well as field observations of membrane slippage in service. Further, causes of slippage are discussed and suggestions made to reduce the incidence of slippage.
Date
11/1972
11/1972
Author(s)
Cramp, A; Cullen, William; Tyron, Max
Cramp, A; Cullen, William; Tyron, Max
Page(s)
90
90
Keyword(s)
asphalt, bitumen; coal tar pitch; softening point fall back; roof slippage; viscosity
asphalt, bitumen; coal tar pitch; softening point fall back; roof slippage; viscosity