The not-so-new self-adhered roof membraneDick Baxter
In the rush to provide environmentally friendly, nontoxic,
odorless, colorless, tasteless, benign, harmless, cheap,
super-reflective energy-efficient roof membrane materials,
self-adhered bituminous and nonbituminous roof membranes are being
reintroduced to the roofing marketplace. The concept is not new;
the first self-adhered roof membrane systems date back almost 30
years. There have been some relatively modest improvements and
modifications to old formulations, but the basic self-adhered roof
membrane properties remain essentially the same—they stick to
their substrates without extraneous adhesives.
The material
Original self-adhered roof membrane systems were produced from
asphalts altered with polymer modifiers. Plastic films were applied
to top surfaces of the membranes and parting sheets to the bottoms.
As a material roll was set in place, the release/parting paper on
the bottom side of the sheet was removed to expose the sticky
bottom side of the membrane. To ensure continuous contact of the
sticky bottom side with the substrate, lawn rollers were used to
press the membrane into place. Various surfacings were used to
protect the ultraviolet- (UV-) sensitive waterproofing material
from exposure.
The "new" self-adhered roof membrane systems come in two
varieties—bituminous and polymeric. Various surfacing
materials or UV stabilizers are factory-included and replace the
original plastic films and field-applied surfacings. But parting
sheets remain on the bottom sides of the sheets to be removed in
the field. As a material roll is set in place, the release/parting
paper on the bottom side of the sheet is removed to expose the
sticky bottom side of the membrane. To ensure continuous contact of
the sticky bottom side with the substrate, rollers are recommended
to press the membrane into place. Various surfacings/stabilizers
are being used to protect the UV-sensitive waterproofing material
from exposure....
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