Glossary - Revision history

James Klassen: /* P */

2026-03-23T14:11:50Z

‎P

James Klassen: /* W */

2026-03-23T14:07:05Z

‎W

James Klassen: /* E */

2025-12-12T19:51:04Z

‎E

James Klassen: /* H */

2025-12-12T19:42:17Z

‎H

James Klassen: /* V */

2025-12-02T16:15:15Z

‎V

James Klassen: /* O */

2025-08-01T16:28:56Z

‎O

James Klassen: /* S */

2025-08-01T16:25:21Z

‎S

James Klassen: /* A */

2024-12-13T16:54:14Z

‎A

James Klassen: /* G */

2024-10-18T23:04:13Z

‎G

James Klassen: /* P */

2024-08-13T16:09:57Z

‎P

@@ Line 806: / Line 806: @@
 ;PRIMARY MATERIAL
-:means a material used in a roof or grade-level waterproofing ''system'' that protects a building interior from water.  ''Primary materials'' are often exposed to the weather (protected membranes are an exception), and therefore also protect ''secondary materials'' from damage.  Membranes, metal panels, asphalt shingles, and cedar shakes and shingles, form the core body of materials classified as ''primary''.
+:A ''primary material'' is a waterproofing or water-shedding material which that is usually exposed to the weather and is primarily responsible for protecting ''secondary materials'' and the building interior from water and weather.
 ;PRIMARY ROOF DRAIN (PRIMARY DRAIN)

@@ Line 1,257: / Line 1,257: @@
 ;WATERPROOFING ASSEMBLY
-:means a ''Waterproofing System'' in combination with the structural surface (deck) that supports it.
+:means a ''waterproofing system'' in combination with the structural surface (deck) that supports it.
 ;WATERPROOFING ROOF SYSTEM
-:means an insulated or uninsulated ''roof system'', designed and constructed on roofs using a sheet or liquid-applied membrane, to exclude water.  This type of ''system'' typically is installed on roof slopes less than 1:4 (3” in 12”).
+:means an insulated or uninsulated ''waterproofing system'' installed on a roof, typically with a slope less than 1:4 (3” in 12”).
 ;WATERPROOFING SYSTEM
@@ Line 1,269: / Line 1,269: @@
 ;WATER-SHEDDING ASSEMBLY
-:means a "Water-shedding Roof System" in combination with the structural surface (deck) that supports it.
+:means a "Water-shedding roof system" in combination with the structural surface (deck) that supports it.
 ;WATER-SHEDDING ROOF SYSTEM
-:means an insulated or uninsulated ''roof system'', designed and constructed to shed water away from a structure, not to waterproof it.  This type of ''system'' typically is installed on roof slopes greater than 1:4 (3” in 12”) but may be installed on slopes as low as 1:6 (2" in 12").
+:means an insulated or uninsulated ''roof system'' that is designed and constructed to shed water away from a structure, not to waterproof it, and is typically installed on roof slopes greater than 1:4 (3” in 12”) but which may be installed on slopes as low as 1:6 (2" in 12").
 ;WIND UPLIFT

@@ Line 389: / Line 389: @@
 ;EXPOSURE
-:(1) The transverse dimension of a roofing element not overlapped by an adjacent element in any roof system. The exposure of any ply in a membrane may be computed by dividing the felt width minus  50 mm (2") by the number of shingled plies; thus, the exposure of a 914 mm (36") wide felt in a shingled, four-ply membrane should be 216 mm (8-1/2")
+:means the time during which a portion of a roofing element is exposed to the weather.
-:(2) The time during which a portion of a roofing element is exposed to the weather;
+;EXPOSURE (Asphalt Shingles)
+:means the portion of an asphalt shingle exposed to the weather.
 ;EXTENSIVE VEGETATIVE ROOF SYSTEM

@@ Line 517: / Line 517: @@
 {{Special:PrefixIndex/Glossary:H}}
 ;HEADLAP
-:The minimum distance, measured at 90<sup>o</sup> to the eaves along the face of a shingle or felt, from the upper edge of the shingle or felt to the nearest exposed surface.
+:means the upper portion of an installed asphalt shingle that is covered by the next overlapping course of shingles.
 ;HEAT AGING

@@ Line 1,228: / Line 1,228: @@
 ;VENT
 :An opening designed to convey water vapour or other gas from inside a building or a building component to the atmosphere, thereby relieving vapour pressure.
 ;VERMICULITE

@@ Line 723: / Line 723: @@
 :Any material, structure or item of equipment that is placed on top of (but not fastened to or through) a ''Waterproofing System''. Gravel or pavers are considered ''overburden'' when they do not function as securement for the ''roof system''. See also '''BALLAST'''.
-;OVERFLOW DRAIN ("overflow")
+;OVERFLOW DRAIN ("Overflow")
-:means a ''secondary roof drain''
+:Emergency discharge outlets located around the perimeter of a roof or in the roof field, to alleviate the over-accumulation of water on the roof surface when primary and secondary drains are unable to function.
 ==P==

@@ Line 927: / Line 927: @@
 ;SCUPPER DRAIN ("Scupper")
-:means an open or closed roof drain that conveys water laterally from one roof area to another, or from the roof directly to the exterior of the building.
+:means an open or closed roof drain that conveys water laterally from one roof area to another, or from the roof directly to the exterior of the building.  Scuppers may serve as a primary or secondary drain, and are functionally different from overflows, which are used for the emergency discharge of water off a roof.
 ;SEAL

@@ Line 41: / Line 41: @@
 ;ALLOY
 :A combination of two or more chemically different polymers which have been re-formed through processing into a new material from which the original materials cannot be separated.
 ;APPLICATION RATE

@@ Line 499: / Line 499: @@
 :See '''VEGETATED ROOF SYSTEM''' or '''VEGETATED ROOF ASSEMBLY'''.
-;GROWING MEDIA
+;GROWING MEDIA (GROWTH MEDIA)
 :means a certified, engineered blend of organic and inorganic materials designed to provide a stable medium for roots, to permit the absorption of air, water, and nutrients by plants, and to function as a water detention material to absorb and gradually release rainwater.  The term is used interchangeably with '''SOIL''' in the "Standard for Vegetated Roof Assemblies" but must not be confused with TOPSOIL, which is naturally occurring soil at the surface of the ground, above the subsoil layer.

@@ Line 822: / Line 822: @@
 :A roofing assembly in which the roof membrane is applied at the structural deck level and the insulation is placed above the membrane and ballasted. Also called inverted or upside-down roof.
-;PROTECTED ROOF SYSTEM (PROTECTED MEMBRANE ROOF SYSTEM)
+;PROTECTED ROOF SYSTEM (PROTECTED MEMBRANE ROOF SYSTEM, PROTECTED)
 :A ''roof system'' of a ''Protected Roof Assembly'' that is constructed above a deck to form an assembly.