This 18 inch perforated roller cover carries a 3/8 in. nap on a poly core and is built for applying adhesive on single-ply and built-up roofing. The 18 in. width is the standard for field application, where covering area fast is the whole point.

The perforations are the part worth understanding. A solid core traps air when the cover saturates with adhesive, and that trapped air pushes back and causes the cover to slip or spin on the frame mid-pull. A perforated core lets the air out, so the cover stays put and loads evenly. On a hot roof with a fast-flashing adhesive, that is the difference between a clean pull and a streaked one.

The 3/8 in. nap is the right length for the smooth substrates most adhesive work goes over. Longer naps hold more material but leave a heavier, less even film, which wastes adhesive and can slow cure.

Poly core instead of cardboard means the cover will not go soft and collapse when it is saturated, which is the usual reason a cheap cover fails halfway through a section.

Sold 12 per carton, which is how roller covers get used. They are a consumable, and a crew that is rolling adhesive all day will go through several.

• 18 in. width

• 3/8 in. nap

• Perforated poly core

• For adhesive application on single-ply and built-up roofing

• 12 per carton