Difference between revisions of "Draft Template:Part 5 (Waterproofing Roofs)"

Jump to: navigation, search

Difference between revisions of "Draft Template:Part 5 (Waterproofing Roofs)"

(Walls)
Line 14: Line 14:
 
==Materials==
 
==Materials==
 
<ol>
 
<ol>
<li>Deck and wall overlays must be suitable for, and compatible with, any membrane or panel application.  Plywood, measuring at least 12.7 mm (1/2”) in thickness, is acceptable as a deck or wall overlay; for roofs supporting an overburden, the plywood must be at least 16 mm (5/8”) thick.
+
<li>''Deck'' and ''wall'' overlays must be suitable for, and compatible with, any membrane or panel application.  Plywood, measuring at least 12.7 mm (1/2”) in thickness, is acceptable as a ''deck'' or ''wall'' overlay; for roofs supporting an ''Overburden'', the plywood must be at least 16 mm (5/8”) thick.
 
<li><span class="principles">Self-adhering or adhesive-applied materials should be considered as alternatives to torch-applied membranes when the substrate to which they will be applied is combustible, or when nearby structures, openings or materials present a fire hazard.</span>  In the alternative, a suitable separation or overlay material as protection from open flame is acceptable.  The application of materials to a combustible surface, using a torch, is strictly prohibited.
 
<li><span class="principles">Self-adhering or adhesive-applied materials should be considered as alternatives to torch-applied membranes when the substrate to which they will be applied is combustible, or when nearby structures, openings or materials present a fire hazard.</span>  In the alternative, a suitable separation or overlay material as protection from open flame is acceptable.  The application of materials to a combustible surface, using a torch, is strictly prohibited.
<li>When the Building Code having jurisdiction requires a thermal barrier, an accepted deck overlay must be specified and installed.
+
<li>When the Building Code having jurisdiction requires a thermal barrier, an accepted ''deck'' overlay must be specified and installed.
 
<li>Walls that require resurfacing for membrane application must be covered with an accepted wall overlay.  See Accepted [http://rpm.rcabc.org/index.php/Wall_Overlays '''Wall Overlays'''].
 
<li>Walls that require resurfacing for membrane application must be covered with an accepted wall overlay.  See Accepted [http://rpm.rcabc.org/index.php/Wall_Overlays '''Wall Overlays'''].
<li>Fasteners used to secure deck overlays must be corrosion-resistant or resin-coated, and must be used together with plates when specified or listed in a ''Tested Assembly'' report.
+
<li>Fasteners used to secure ''deck'' overlays must be corrosion-resistant or resin-coated, and must be used together with plates when specified or listed in a ''Tested Assembly'' report.
 
<li>See also Accepted [http://rpm.rcabc.org/index.php/Roof_Deck_Overlays '''Roof Deck Overlays'''].
 
<li>See also Accepted [http://rpm.rcabc.org/index.php/Roof_Deck_Overlays '''Roof Deck Overlays'''].
 
</li></ol>
 
</li></ol>
Line 25: Line 25:
 
===General===
 
===General===
 
<ol>
 
<ol>
<li>Deck overlays must be
+
<li>''Deck'' overlays must be
 
<ol>
 
<ol>
<li>fully or intermittently supported along all edges by the deck.
+
<li>fully or intermittently supported along all edges by the ''deck''.
 
<li>installed in a staggered pattern (offset) 300 mm (12") from adjacent board rows.  A minus offset tolerance of 50 mm (2") maximum will be permitted to compensate for variance in the manufacturer's tolerance of differing board widths and lengths.
 
<li>installed in a staggered pattern (offset) 300 mm (12") from adjacent board rows.  A minus offset tolerance of 50 mm (2") maximum will be permitted to compensate for variance in the manufacturer's tolerance of differing board widths and lengths.
<li>affixed to the deck with either or both
+
<li>affixed to the ''deck'' with either or both
 
<ol>
 
<ol>
 
<li>mechanical fasteners.
 
<li>mechanical fasteners.
<li>proprietary polyurethane foam adhesives acceptable to the primary roof system manufacturer to meet or exceed the requirements set out in '''3 SECURING the ROOF ASSEMBLY'''.
+
<li>proprietary polyurethane foam adhesives acceptable to the primary ''roof system'' manufacturer to meet or exceed the requirements set out in '''Part 3 SECURING the ROOF ASSEMBLY'''.
 
</li></ol>
 
</li></ol>
<li>independently fastened to the deck in keeping with either of the following:
+
<li>independently fastened to the ''deck'' in keeping with either of the following:
 
<ol>
 
<ol>
 
<li>at least four (4) fasteners (with plates) per 1200 x 2400 (4’x8’) sheet, or
 
<li>at least four (4) fasteners (with plates) per 1200 x 2400 (4’x8’) sheet, or
<li>as required by a ''Tested Assembly'', when part of a '''PARS''' or '''MARS''' conventionally insulated roof assembly.
+
<li>as required by a ''Tested Assembly'', when part of a '''PARS''' or '''MARS''' ''Conventionally Insulated System''.
 
</li></ol>
 
</li></ol>
 
</li></ol>
 
</li></ol>
<li>Wall overlays
+
<li>''Wall'' overlays
 
<ol>
 
<ol>
 
<li>must be applied to existing sheathing, where existing sheathing is not an acceptable substrate.
 
<li>must be applied to existing sheathing, where existing sheathing is not an acceptable substrate.
Line 50: Line 50:
 
===Steel Decks===
 
===Steel Decks===
 
<ol>
 
<ol>
<li>RoofStar-accepted deck overlay boards used as a thermal barrier to achieve a specific fire rating must conform to the applicable code and insurance requirements for the roof assembly.  
+
<li>RoofStar-accepted ''deck'' overlay boards used as a thermal barrier to achieve a specific fire rating must conform to the applicable code and insurance requirements for the ''roof system''.  
<li>When the roof assembly is uninsulated, the deck must be overlaid with at least one layer of 12.7 mm (1/2”)
+
<li>When the ''roof system'' is uninsulated, the ''deck'' must be overlaid with at least one 12.7 mm (1/2”) thick layer of either
 
<ol>
 
<ol>
<li>moisture resistant gypsum core deck overlay board, or with
+
<li>moisture resistant gypsum core ''deck'' overlay board.
 
<li>plywood.
 
<li>plywood.
 
</li></ol>
 
</li></ol>
Line 60: Line 60:
 
===Concrete Decks===
 
===Concrete Decks===
 
<ol>
 
<ol>
<li>A deck overlay board is not mandatory on a concrete supporting deck.
+
<li>A ''deck'' overlay board is not mandatory on a concrete ''supporting deck''.
 
</li></ol>
 
</li></ol>
  
 
===Wood Decks===
 
===Wood Decks===
 
<ol>
 
<ol>
<li>A mechanically-fastened overlay board is required for any deck structure that does not meet the deck fastening criteria set out in '''2.3.3.3 Wood'''.
+
<li>A mechanically-fastened overlay board is required for any ''deck'' structure that does not meet the ''deck'' fastening criteria set out in '''2.3.3.3 Wood'''.
<li>Regardless of the type of deck overlay selected by the ''Design Authority'', the overlay boards shall be installed in a staggered pattern (offset) 300 mm (12") from adjacent board rows.  A minus offset tolerance of 50 mm (2") maximum will be permitted to compensate for variance in the manufacturer's tolerance of differing board widths and lengths.
+
<li>Regardless of the type of ''deck'' overlay selected by the ''Design Authority'', the overlay boards shall be installed in a staggered pattern (offset) 300 mm (12") from adjacent board rows.  A minus offset tolerance of 50 mm (2") maximum will be permitted to compensate for variance in the manufacturer's tolerance of differing board widths and lengths.
<li>Adhering a primary roof membrane directly to a wood deck is not acceptable.
+
<li>Adhering a primary roof membrane directly to a wood ''deck'' is not acceptable.
<li>Notwithstanding Article 3 above, a self-adhered air or vapour control layer may be applied to a supporting wood deck.
+
<li>Notwithstanding Article 3 above, a self-adhered air or vapour control layer may be applied to a supporting wood ''deck''.
<li>Mechanically-fastened or loose-laid membranes applied directly to a supporting wood deck structure do not require a deck overlay board unless specified by the membrane manufacturer.
+
<li>Mechanically-fastened or loose-laid membranes applied directly to a supporting wood ''deck'' structure do not require a ''deck'' overlay board unless specified by the membrane manufacturer.
 
</li></ol>
 
</li></ol>
  
Line 75: Line 75:
 
<ol>
 
<ol>
 
<li>Where the ''wall'' surface is unsuitable to receive a membrane, it must be covered with an accepted overlay panel material {{hilite | (refer to '''Division C: Accepted Materials''' in this ''Manual'')|| 2021-June-30 }}.
 
<li>Where the ''wall'' surface is unsuitable to receive a membrane, it must be covered with an accepted overlay panel material {{hilite | (refer to '''Division C: Accepted Materials''' in this ''Manual'')|| 2021-June-30 }}.
<li>Wall overlay panels must be
+
<li>''Wall'' overlay panels must be
 
<ol>
 
<ol>
 
<li>mechanically fastened with screw fasteners spaced no more than 300 mm (12”) O.C. vertically and horizontally, in alignment with structural supports, and placed  
 
<li>mechanically fastened with screw fasteners spaced no more than 300 mm (12”) O.C. vertically and horizontally, in alignment with structural supports, and placed  

Revision as of 17:06, 30 June 2020

See more information on Roof Deck Overlays in Section B: Essential Elements.

1 General

1.1 Definitions

Refer to the Glossary for further definitions of key terms used in this Manual. See also 2.1.1 Definitions..

1.2 Design

  1. When a supporting deck structure or wall is unsuitable for the application of roofing materials, it must be covered with a RoofStar-accepted overlay. See 2.1 (3) for supporting deck and wall surface requirements.
  2. A roof deck overlay (also called a system underlay) is installed as part of the Roof Assembly, on the top surface of the roof deck but beneath the roofing materials. These products are most commonly affixed to steel decks to provide a level surface for the roof membrane, to support air or vapour control layers, or to serve as a thermal barrier between the roof deck and combustible insulation. Roof deck overlay materials may also be applied to other types of supporting deck structures, depending on the roof design criteria.
  3. When a roof design includes any type of overburden, the deck overlay on steel decks, or on wood decks less than 25 mm (1” ) thick, should be at least 16 mm (5/8”) thick, in order to stiffen the supporting surface and reduce deck deflection.

2 Materials

  1. Deck and wall overlays must be suitable for, and compatible with, any membrane or panel application. Plywood, measuring at least 12.7 mm (1/2”) in thickness, is acceptable as a deck or wall overlay; for roofs supporting an Overburden, the plywood must be at least 16 mm (5/8”) thick.
  2. Self-adhering or adhesive-applied materials should be considered as alternatives to torch-applied membranes when the substrate to which they will be applied is combustible, or when nearby structures, openings or materials present a fire hazard. In the alternative, a suitable separation or overlay material as protection from open flame is acceptable. The application of materials to a combustible surface, using a torch, is strictly prohibited.
  3. When the Building Code having jurisdiction requires a thermal barrier, an accepted deck overlay must be specified and installed.
  4. Walls that require resurfacing for membrane application must be covered with an accepted wall overlay. See Accepted Wall Overlays.
  5. Fasteners used to secure deck overlays must be corrosion-resistant or resin-coated, and must be used together with plates when specified or listed in a Tested Assembly report.
  6. See also Accepted Roof Deck Overlays.

3 Application

3.1 General

  1. Deck overlays must be
    1. fully or intermittently supported along all edges by the deck.
    2. installed in a staggered pattern (offset) 300 mm (12") from adjacent board rows. A minus offset tolerance of 50 mm (2") maximum will be permitted to compensate for variance in the manufacturer's tolerance of differing board widths and lengths.
    3. affixed to the deck with either or both
      1. mechanical fasteners.
      2. proprietary polyurethane foam adhesives acceptable to the primary roof system manufacturer to meet or exceed the requirements set out in Part 3 SECURING the ROOF ASSEMBLY.
    4. independently fastened to the deck in keeping with either of the following:
      1. at least four (4) fasteners (with plates) per 1200 x 2400 (4’x8’) sheet, or
      2. as required by a Tested Assembly, when part of a PARS or MARS Conventionally Insulated System.
  2. Wall overlays
    1. must be applied to existing sheathing, where existing sheathing is not an acceptable substrate.
    2. may be mechanically fastened or adhered.
    3. may be replaced with an accepted material.

3.2 Steel Decks

  1. RoofStar-accepted deck overlay boards used as a thermal barrier to achieve a specific fire rating must conform to the applicable code and insurance requirements for the roof system.
  2. When the roof system is uninsulated, the deck must be overlaid with at least one 12.7 mm (1/2”) thick layer of either
    1. moisture resistant gypsum core deck overlay board.
    2. plywood.

3.3 Concrete Decks

  1. A deck overlay board is not mandatory on a concrete supporting deck.

3.4 Wood Decks

  1. A mechanically-fastened overlay board is required for any deck structure that does not meet the deck fastening criteria set out in 2.3.3.3 Wood.
  2. Regardless of the type of deck overlay selected by the Design Authority, the overlay boards shall be installed in a staggered pattern (offset) 300 mm (12") from adjacent board rows. A minus offset tolerance of 50 mm (2") maximum will be permitted to compensate for variance in the manufacturer's tolerance of differing board widths and lengths.
  3. Adhering a primary roof membrane directly to a wood deck is not acceptable.
  4. Notwithstanding Article 3 above, a self-adhered air or vapour control layer may be applied to a supporting wood deck.
  5. Mechanically-fastened or loose-laid membranes applied directly to a supporting wood deck structure do not require a deck overlay board unless specified by the membrane manufacturer.

3.5 Walls

  1. Where the wall surface is unsuitable to receive a membrane, it must be covered with an accepted overlay panel material (refer to Division C: Accepted Materials in this Manual).
  2. Wall overlay panels must be
    1. mechanically fastened with screw fasteners spaced no more than 300 mm (12”) O.C. vertically and horizontally, in alignment with structural supports, and placed
      1. at the perimeters.
      2. at the corners.
      3. in the field.
    2. adhered with a polyurethane adhesive, applied with a continuous z-patterned ribbon spaced no less than 300 mm (12”) apart.