References - Page 29

Glossary

INVERTED ROOF MEMBRANE ASSEMBLY (IRMA) A patented variation of the "Protected Membrane Roof Assembly" in which

STYROFOAM Brand insulation and ballast are placed over the membrane. (Also PRMA.)

ISOCYANURATE See POLYISOCYANURATE INSULATION.

KETTLE A portable device for heating asphalt.

LAP That part of a roofing membrane which overlaps or covers any portion of another section of membrane which is then sealed to form a watertight connection.

LOOSE-LAID MEMBRANE A ballasted, single ply roofing membrane that is attached to the substrate only at the building edges and penetrations through the roof.

LUGGER A device for moving hot asphalt across a roof surface.

MAT A thin layer of woven, non-woven, or knitted fiber which serves as reinforcement to the membrane.

MB Abbreviation for "Modified Bitumen."

MESH The square opening of a sieve. Also, an open weave material used as a reinforcement in bituminous, cold process applications.

METAL FLASHING See FLASHING; frequently used as through-wall, cap, or counterflashing.

MIL A unit of measure used to indicate the thickness of a roofing membrane. One mil is equal to 0.001 inches or 25,400 microns (0.0254 mm).

MINERAL GRANULES Opaque, natural, or synthetically colored aggregate commonly used to surface cap sheets, granule-surfaced sheets and roofing shingles.

MINERAL STABILIZER A fine, water-insoluble, inorganic material, used in admixture with solid or semi-solid bituminous materials.

MINERAL-SURFACED ROOFING  Built-up roofing whose top ply consists of a granule-surfaced sheet.

MINERAL-SURFACED (CAP) SHEET A felt that is coated on one or both sides with asphalt and surfaced with mineral granules.

MODIFIED BITUMEN A material consisting of asphalt which has been modified through the inclusion of one or more polymers and may contain stabilizers and other additives. Modified bitumen roofing membranes may also contain a reinforcing material.

MOLE RUN A meandering ridge in a membrane not associated with insulation or deck joints.

MOP-AND-FLOP A procedure in which roofing elements (insulation boards, felt plies, cap sheets, etc.) are initially placed upside down adjacent to their ultimate locations, are coated with adhesive, and are then turned over and adhered to the substrate.

MOPPING The application of hot asphalt with a mop or mechanical applicator to the substrate or to the plies of a bituminous roof. There are four types of mopping:

(1) Solid – a continuous coating; (2) Spot – asphalt is applied in spots, leaving a grid of unmopped, perpendicular areas; (3) Strip – asphalt is applied in parallel bands, generally 8 inches (203 mm) wide and 12 inches (305 mm) apart; (4) Sprinkle – asphalt is shaken onto the substrate from a broom or mop in a random pattern.

MUD CRACKING Surface cracking resembling a dried mud flat.

NAILER A piece of dimension lumber or plywood secured to the structural deck or walls, which provides a receiving medium for the fasteners used to attach the membrane or flashing. Nailers must be the same thickness as the insulation, and should be treated with a non-oil-borne preservative.

NEOPRENE Elastomeric membranes made by the polymerization of chloroprene (polychloroprene).

NIGHT SEAL A material used to temporarily seal a membrane edge during construction to protect the roofing assembly in place from water penetration. (Also CUTOFF.)

NINETY-POUND A prepared roll roofing with a granule-surfaced exposure that has a mass of approximately 90 lbs./108 ft² (4.05 kg/m²).

NON-VULCANIZED MEMBRANE A membrane manufactured from thermoplastic compounds that has not been heat cured and retains its thermoplastic properties throughout the life of the membrane.

NON-WOVEN A term used to describe the random arrangement of reinforcing fibers (glass, polyester, etc.) in a mat or scrim.

NRCA Abbreviation for "National Roofing Contractors Association."

OPEN TIME The period of time during which an effective bond can be achieved by joining two surfaces after a contact adhesive has been applied and allowed to dry.

ORGANIC Any chemical or chemical compound which is composed of, or which contains carbon.

PARTING AGENT A material applied to one or both surfaces of a sheet to prevent sticking.