Difference between revisions of "Materials:JM Built Up Roofing Systems"

Revision as of 14:13, 19 April 2018

Notice to the Reader: The roofing assembly / material information published in the RCABC Roofing Practices Manual and offered below does NOT represent a complete set of the manufacturer’s data or specifications. The preparation of a detailed specification is the responsibility of the design authority.

Manufacturer: Johns Manville Corporation

Accepted for RoofStar Guarantee Program: 1995

Product Summary: This is a Johns Manville Built Up Roofing Specification utilizing Johns Manville GlasPly IV, GlasPly Premier and Perma Ply R glass felts. Johns Manville flashing products include GlasTite, DynaFlex and Expand-O-Flash. Unless otherwise listed separately in this Manual as a stand-alone Material, the products listed here are acceptable only when utilized in the assemblies described below. For each material, see the downloadable Technical Data Sheets at the bottom of this page.

PART I ‑ GENERAL
The roofing assembly / material information published in the RCABC Roofing Practices Manual does NOT represent a complete set of the manufacturer's published data, nor does it represent a detailed specification. The preparation of a detailed specification is the responsibility of the design authority.
1. DELIVERY. STORAGE AND HANDLING
  1. Deliver and store materials in original packages and containers with manufacturer's seals and labels intact.
  2. Keep roofing materials dry; protect from weather conditions.
  3. Store rolls on end.
2. SITE CONDITIONS
  1. Slope Limitations:
    Minimum recommended slope 1:50 (1 / 4" in 12")
    
    Where slopes exceed 1:12, backnail each mopped sheet.
3. STANDARDS AND APPROVALS
  1. Factory Mutual: Refer to Pages 14-32 to 14-48 of Johns Manville's Commercial Industrial Roofing Systems book or binder for approved systems.
PART 2 ‑ PRODUCTS
1. BUILT UP ROOFING MEMBRANE
  1. Johns Manville GlasPly IV, GlasPly Premier or Perma Ply R glass roofing felts conforming to ASTM D2178, Type IV and Type VI.
2. ANCILLARY PRODUCTS ==
  1. Johns Manville Fibrated Aluminum Roof Coating
  2. Johns Manville Industrial Roof Cement
  3. Johns Manville Concrete Primer
  4. Flashing Membrane: Johns Manville GlasTite Flexible
  5. Flashing Membrane: Johns Manville DynaFlex
  6. Flashing Membrane: Johns Manville Expand-O-flash expansion joint covers
  7. Johns Manville Roof Drains: Flex-I-Drain, USII RetroDrain, PC / PET Retrodrain
  8. Johns Manville J-Walk Roof Walkway
  9. Johns Manville UltraFast or UltraGrip Fasteners and Plates
  10. Johns Manville Base Sheets - GlasBase, GlasBase Plus, Ventsulation Felt, PermaPly 28
  11. Gravel: according to RoofStar Guarantee Standards
  12. Permstop Vapour Retarder
PART 3 ‑ EXECUTION
1. PREPARATION
  1. The deck must be properly designed and constructed to support and secure the Johns Manville Roofing System.
  2. The surface to which the roofing system is to be installed must be smooth, clean and dry.
  3. Ensure wood blocking, curbs and cant strips are solidly secured and reglets and nailing strips are in place, as required.
  4. Prepare substrate and apply roofing membrane in accordance with good roofing practices, in accordance with the Standards published in this Manual, for the different deck types.
2. VAPOUR RETARDER (If Specified)
  1. Vapour retarders must be continuously extended throughout the roof plane. All openings in the roof deck must be flashed at the retarder level.
  2. Options depend upon specific job requirements:
    - Install Permstop Vapour Retarder with 50 mm (2") side laps and 100 mm (4") end laps, adhering with ribbons of adhesive or asphalt.
    - Install two plies of Johns Manville PermaPly 28, Glasbase or Glasbase Plus base sheet fully adhering with moppings of hot asphalt.
3. INSULATION
  1. Apply as per RoofStar Guarantee Standards.
4. FLASHINGS
  1. On vertical applications, use 2 plies of Johns Manville modified bituminous membrane lapped on the deck 100 mm and 150 mm (4" and 6"), respectively. Top ply to be granular finished. May also use two plies of Johns Manville GlasTite covered with metal flashing or one ply GlasTite and one ply Johns Manville Dynaflex. All exposed GlasTite must be protected with Johns Manville Aluminised Coating or metal flashing.
  2. On horizontal applications, may use 3-ply GlasPly IV, GlasPly Premier or PermaPly R.
  3. Install Johns Manville Expand-O-Flash over expansion joints, as specified.
5. SURFACE MEMBRANE PROTECTION
  1. Install asphalt floodcoat and gravel as per RoofStar Guarantee Standards.

Manufacturer: JOHNS MANVILLE CORPORATION

Contact Address: See Membership List in Section 1.

Product Group: PROPRIETARY SYSTEMS - GLASS BUILT UP ROOFING Roof Assembly: EXPOSED MEMBRANE, INSULATED

Note: Only components or products listed here and in the RoofStar-accepted Materials section of this Manual may be used. No substitutes are allowed for guarantee purposes.

ROOF ASSEMBLY
Components	Options	Comments or Cautions
Roof Deck	Plywood / wood Concrete Steel	Prime surfaces to be adhered with hot bituminous material. Tape plywood joints if mopped with hot adhesive. Wood decks require a nailed separation sheet. Steel decks require a levelling underlay.
Vapour Retarder	Permstop Vapour Retarder	Adhere with adhesive or asphalt.
Insulation	Polyisocyanurate foam Extruded polystyrene Expanded polystyrene Glass fibreboard Wood fibreboard Fesco Board	Fesco overlay (one or two layers) is suitable when an insulation overlay is required by RoofStar Guarantee Standards. Tape insulation joints where an overlay is not required.
Insulation Overlay	12.7 mm (1/2") Retro-fit Board Glass fibreboard	Where required, install according to RoofStar Guarantee Standards
BUILT UP MEMBRANE
Roof Membrane	Glass felt	Install according to RoofStar Guarantee Standards.
Flashings	GlasTite DynaFlex Expand-O-Flash	Install as per Johns Manville recommendation
Glaze Coat	Type 2 or 3 asphalt.	Apply according to RoofStar Guarantee Standards.
Membrane Surfacing	Gravel	Install according to RoofStar Guarantee Standards.