ROOF SPECIALTIES

GRAVITY AIR VENTS Specification      

 Note: This gravity air vent specification, with minor editing, has been written        as a separate section of work. Alternatively, the appropriate clauses may be incorporated as part roofing specification.

	PART 1 GENERAL

1.01 	SECTION INCLUDES

	A.  Supply and installation of roof accessories, including:
	     1. Gravity air vents.
	     
1.02 	RELATED SECTIONS

	A.  Section 06100 - Rough Carpentry

	B.  Section 07200 - Thermal Protection

	C.  Section 07500 - Membrane Roofing
	
	D.  Section 07900 - Joint Sealers

1.03 	REFERENCES

	[A.  CRCA (Canadian Roofing Contractor’s Association)]

	[B.  NRCA (National Roofing Contractor’s Association)]

	[C.  SPRI (Single Ply Roofing Institute)]

	[D. CUFCA (Canadian Urethane Foam Contractor’s Association) and 
                  CGSB-GP 46MP Manual for  "Installers of Spray Polyurethane Foam   
                  Thermal Insulation" and ASTM C1029-90 "Spray Applied Rigid Cellular 
                   Polyurethane Thermal Insulation"]

1.04 	SUBMITTALS

A.	Manufacturer's descriptive literature for each product, including section or   
      other type details.

	B.  Manufacturer's written installation instructions.

B.	Shop drawings and samples, when required, in accordance with Section    
      [01300]. 

1.05 	QUALITY ASSURANCE

A.	Roof accessories manufacturer to have minimum 5 years documented experience in the design and fabrication of roofing specialties and accessories.

B.	Comply with code requirements of authorities having jurisdiction for calculating area of required ventilation for roof spaces.

1.06 	SPECIAL WARRANTY

A.	Warrant products installed under this section of work to be free of defects in 
       materials and/or manufacture and condensation for a period of 20 years when   
      installed in accordance with the manufacturer's written instructions.

	PART 2 PRODUCTS

2.01 	MANUFACTURER

A.	Provide products as manufactured by Thaler Metal Industries, 1-800-387-7217 (Mississauga, Ontario, Canada) or 1-800-576-1200 (New Braunfels, TX) or provide equal products by another manufacturer approved in advance by the [Architect], based upon:
1.	20 year warranty against leaks, condensation and defects in materials and/or 
     manufacture;
	    2.  maintenance free design;
		    3.  materials and sizes options, and thicknesses;
4.	injection molded urethane insulation to CGSB-51-GP 46MP and ASTM 
      C1029-90, as  
     applicable;
	    5.  treated deck flange, as applicable;
	    6.  written installation instructions.

2.02	MANUFACTURED UNITS

	Note: Delete clauses not applicable.

	GAV-1Gravity Air Vents-Small Size Vents

A.	Gravity air vents: Thaler [GAV-1A] [GAV-1C][GAV-1SS] standard 12" (305 mm) high, [3" (76 mm) to 10” (254 mm)] diameter gravity air vent consisting of [.064" (1.6 mm) mill finish 1100-0T alloy aluminum] [24 oz. 0.032” (0.831 mm) copper] [.031" (0.79 mm) 22 ga. Type 304 stainless steel] with integral deck flange, removable conical hood fitted with three support brackets, insect screen and [bituminous painted deck flange][PVC coated deck flange][plain deck flange].

	GAV-2 Gravity Air Vents (Large Size Vents)
	
B.	Gravity air vents: Thaler [GAV-2A] [GAV-2C][GAV-2SS] standard 12" 
 (305 mm) high  [12” (305 mm) and up] diameter gravity air vent consisting of [.064" (1.6 mm) mill finish 1100-0T alloy aluminum] [24 oz. 0.032” (0.831 mm) copper] [.031" (0.79 mm) 22 ga.) Type 304 stainless steel] with integral deck flange, fixed conical hood fitted with insect screen and support brackets, and [bituminous painted deck flange][PVC coated deck flange][plain deck flange].
	
               GAV-3 Gravity Air Vents-Small Size Vents Sloped Roofs

C.	Gravity air vents: Thaler [GAV-3A] [GAV-3C][GAV-SS3] standard 12" (305 mm) high, [3" (76 mm) to 10 “ (254 mm)] diameter gravity air vent consisting of [.064" (1.6 mm) mill finish 1100-0T alloy aluminum] [24 oz. 0.032” (0.831 mm) copper] [.031" (0.79 mm) 22 ga.) Type 304 stainless steel with integral deck flange, removable conical hood fitted with three support brackets, insect screen and [bituminous painted deck flange][PVC coated deck flange][plain deck  flange].

	GAV-4 Gravity Air Vents (Large Size Vents) Sloped Roofs
	
D.	Gravity air vents: Thaler [GAV-4A] [GAV-4C][GAV-4SS] [_____] high, [12” (305 mm) and up] diameter gravity air vent consisting of [.064" (1.6 mm) mill finish 1100-0T alloy aluminum] [24 oz. 0.032” (0.831 mm) copper] [.031" (0.79 mm) 22 ga.) Type 304 stainless steel] wit integral deck flange, fixed conical hood fitted with insect screen and support brackets, and [bituminous painted deck flange][PVC coated deck flange][plain deck flange].

	PART 3 EXECUTION

3.01 	EXAMINATION

A.	Report to the Contractor in writing, defects of work prepared by other trades and other unsatisfactory  site conditions. Verify site dimensions. Commencement of work will imply acceptance of prepared work.

3.02 	INSTALLATION

	Note: Delete clauses not applicable.

	A. Install flashing in accordance with manufacturer’s printed instructions.

	Note: Items B to F (regarding roof spaces) have been condensed from the 1995  
            National Building Code of Canada  (NBC).  Consult with authorities having    
            jurisdiction for specific data.
	 
B.	Vent roof space or attic above an insulated ceiling with openings to the exterior to provide unobstructed vent area of not less than 1/300 of the insulated ceiling area.

             C.  Uniformly distribute vents on opposite sides of the building.

	D.  Design vents to prevent entry of rain, snow and insects.

E.	Determine unobstructed vent area required in conformance with CAN3-A93, 
      "Natural Airflow Ventilators for Buildings".

F.	For low slope roofs where insulation is placed below roof sheathing in roofs having a slope of less than 1 in 6 or in roofs that are constructed with roof joists, the unobstructed vent area shall be not less than 1/150 of the insulated ceiling area.

	BUR
G.	Set flashing deck flange in layer of plastic cement and flash in with 3 overlapping layers of felt flashing.

	Modified Bitumen
H.	Torch membrane until bitumen is fluid and set deck flange into fluid. Flash in 
       flange with two overlapping layers of ModBit and seal with asphalt sealer. 

	Single Ply
I.	Set deck flange in layer of membrane adhesive and extend single ply up sleeve to highest elevation possible and clamp membrane to gravity air vent.

	Note: For PVC membrane, specify PVC coated deck flange by adding suffix P to  
            end of Thaler model number, e.g. GAV-1A-P; weld roofing to deck flange using  
            PVC  torch.

	PVC Single Ply
J.	Set deck flange in layer of membrane adhesive and extend single ply up sleeve to highest elevation possible and clamp membrane to flashing. Weld roofing to deck flange using PVC torch.

3.03 	FIELD QUALITY CONTROL

	A. Comply with the requirements of Section [01400-Quality Control].

3.04 	ADJUSTING 

A.	Verify that all manufactured units have been installed in accordance with specifications and details, and will function as intended. Adjust any items where necessary to ensure proper operation.

            CLEANING

3.05      A. Clean manufactured units using materials and methods approved by   
      manufacturer. Do not use cleaners or techniques which could impair   
      performance of the roofing system.

		End of Section