Notes to ASM Standard - Revision history

James Klassen: /* Notes to Part 9 */

2026-08-28T21:06:54Z

‎Notes to Part 9

James Klassen: /* {{hilite | A-9.2.1.1.(5)(2) Metal Panels and the Coefficient of Thermal Expansion || 2026-February-15 }} */

2026-08-28T21:05:26Z

‎{{hilite | A-9.2.1.1.(5)(2) Metal Panels and the Coefficient of Thermal Expansion || 2026-February-15 }}

James Klassen: /* A-1.1.3.1. Permitted Roof Systems */

2026-07-23T17:54:51Z

‎A-1.1.3.1. Permitted Roof Systems

James Klassen: /* A-1.1.3.2. Snow Loads */

2026-07-23T17:54:39Z

‎A-1.1.3.2. Snow Loads

James Klassen at 18:38, 30 January 2026

2026-01-30T18:38:47Z

James Klassen: /* A-2.1.5.5. All Wood Roof Decks */

2025-08-20T21:32:07Z

‎A-2.1.5.5. All Wood Roof Decks

Show changes

@@ Line 260: / Line 260: @@
 :Because the degree of linear movement increases with panel length, the registered professional responsible for designing panel securement should consider anchoring the mid-point of very long panels to allow for bi-directional expansion and contraction or segment long panels into more moderate lengths.  However, each solution presents its own challenges.  Affixing panels at an end or in the middle forces expansion and contraction away from the anchoring point.  This must be considered when designing panel terminations.  For example, flashing detail at the roof-wall intersection will have to allow for movement.  This means that nothing from the ''wall'' should be immovably affixed to the panel end, which may expand or contract considerably; affixing anything to the panel end could result in damage to the panel, flashings, or other adjoining assemblies, and could result in leaking.
 <div id=A-9.2.1.1.(5)(4)></div>
@@ Line 276: / Line 269: @@
 :Finally, when segmenting panels is permitted by a Variance, each panel should be secured so that it moves independently of the other.  This will necessitate a careful design of the transition so that the panels are properly secured to resist expected service conditions and loads, while simultaneously ensuring freedom of expansion and contraction and effective drainage.
 <div id=A-9.2.1.5.></div>

← Older revision		Revision as of 21:05, 28 August 2026
Line 260:		Line 260:

	:Because the degree of linear movement increases with panel length, the registered professional responsible for designing panel securement should consider anchoring the mid-point of very long panels to allow for bi-directional expansion and contraction or segment long panels into more moderate lengths. However, each solution presents its own challenges. Affixing panels at an end or in the middle forces expansion and contraction away from the anchoring point. This must be considered when designing panel terminations. For example, flashing detail at the roof-wall intersection will have to allow for movement. This means that nothing from the ''wall'' should be immovably affixed to the panel end, which may expand or contract considerably; affixing anything to the panel end could result in damage to the panel, flashings, or other adjoining assemblies, and could result in leaking.		:Because the degree of linear movement increases with panel length, the registered professional responsible for designing panel securement should consider anchoring the mid-point of very long panels to allow for bi-directional expansion and contraction or segment long panels into more moderate lengths. However, each solution presents its own challenges. Affixing panels at an end or in the middle forces expansion and contraction away from the anchoring point. This must be considered when designing panel terminations. For example, flashing detail at the roof-wall intersection will have to allow for movement. This means that nothing from the ''wall'' should be immovably affixed to the panel end, which may expand or contract considerably; affixing anything to the panel end could result in damage to the panel, flashings, or other adjoining assemblies, and could result in leaking.
		+
		+	<div id=A-9.2.1.3.(1)></div>
		+
		+	===={{hilite \| A-9.2.1.3.(3) Pre-painted Finishes \|\| 2027-June-11 }}====
		+	:PVDF coatings have a reputation for providing superior protection from extreme temperatures, sun exposure, oxygen, humidity, and airborne pollution (particulate). Formulated to retain their colour, PVDF coatings resist chalking and fading, and will also resist cracking, flaking, and peeling (film adhesion). Said to be ideal where bright colours are desirable, PVDF is also softer than its competitor, SMP. This makes PVDF more flexible, resisting cracking when bent tightly. However, it also means PVDF can be more susceptible to scratching and scuffing; the material is delivered with a protective film which is removed after installation.
		+
		+	:While SMP coatings can provide superior scratch resistance when compared to PVDF they are likely to chalk and fade more than PVDF coated metals, especially when significantly exposed to ultraviolet light. Some manufacturers recommend SMP for less vivid colour choices.

	<div id=A-9.2.1.1.(5)(4)></div>		<div id=A-9.2.1.1.(5)(4)></div>

@@ Line 33: / Line 33: @@
 :Metal roofing panels are roll-formed in full rafter length pans that are fastened to ''decks'' with metal clips and screws, or are manufactured with perforations or slots to facilitate concealed fastening. Galvanized steel and wood are the most common ''deck'' materials used with architectural metal roofing.
-<div id=A-1.1.3.2.></div>
+<div id=A-1.1.3.3.></div>
 ====A-1.1.3.3. Snow Loads====

@@ Line 35: / Line 35: @@
 <div id=A-1.1.3.2.></div>
-====A-1.1.3.2. Snow Loads====
+====A-1.1.3.3. Snow Loads====
 :To determine if a building is located in a high snow load area, the ''Design Authority'' must calculate the anticipated snow loads for the roof, using the building code having jurisdiction.  The following references are extracted from the ''British Columbia Building Code'':
 :*''Div. B, 4.1.6.2 Specified Snow Load'' (see the formula for calculating snow loads).

@@ Line 213: / Line 213: @@
 <div id=A-7.1.3.4.></div>
-====A-7.1.3.4. Effective Thermal Resistance and Layering====
+====A-7.1.3.4. {{strike| Effective || 2026-January-28 }} {{hilite | Thermal Resistance and Layering|| 2027-February-1 }}====
 :{{hilite | In warm seasons, the roof surface may reach temperatures higher than 85°C (185°F), affecting the performance and stability of some insulation. Consequently, the requirement which limits panel size in single-layer applications ensures that inevitable gaps between adjacent panels are kept to a minimum.  Combining insulation types in a ''roof system'' may help mitigate these temperature swings and the consequence of thermal contraction. The ''Design Authority'' therefore must consider these variables when specifying materials and their installation. || 2023-June-16 }}
@@ Line 219: / Line 219: @@
 :{{hilite | The "Long-Term Thermal Resistance" (LTTR) measurement of closed-cell insulation materials remains the standard by which insulation performance is measured.  Published R-values should reflect the LTTR of the material.  In Canada, two principal standards apply to the accurate measurement of thermal resistance: CAN/ULC-S770 ("Standard Test Method for Determination of Long-Term Thermal Resistance of Closed-Cell Thermal Insulating Foams") and CAN/ULC-S704.1 ("Standard for Thermal Insulation, Polyurethane and Polyisocyanurate, Boards, Faced"). || 2023-June-16 }}
 <div id=A-7.1.4.2.></div>