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TP Section 2: Control Joint, Perimeters and Penetrations

TP-2.1 Control Joints

TP-2.1.1 General

.1

Roofing control joints may be required to prevent structural movement or stresses within the roofing system from damaging thermoplastic membranes.

.2

For new construction, for building additions and for re-roofing, control joints shall be installed between the new and existing roofing systems. The Warranty Certificate will only be issued on self-contained roof areas/sections.

.3

Two types of control joints may be used for roofing, construction expansion joints and roof area dividers.

.4

To qualify for an ARCA 15 Year Warranty Certificate, new metal flashing shall be installed at all control joints.
Added

2015-12

TP-2.1.2 Construction Expansion Joints

.1

The building construction expansion joint is incorporated by the design authority when differential structural movement is anticipated.

.2

Roofing expansion joints typically are of double curb/plate construction, fastened on opposite sides of the structural separation, or as otherwise approved by the membrane manufacturer and ARCA Warranty Ltd.

.3

For conventional roofing designs, the top of the expansion joint shall extend a minimum distance of 200mm (8”) above the finished roof surface.

.4

Drainage openings are not permitted through roof expansion joints.

TP-2.1.3 Roof Area Dividers

.1

A roof area divider is incorporated to divide the roofing system into manageable sections and to protect the membrane from stress related damage.

.2

For thermoplastic roofing membranes, roof area dividers may be required where membrane stress points are likely to occur, such as at changes in roof deck direction or deck construction type. Please consult with the membrane manufacturer for their roof area divider requirements. (Refer to MB 2.1.3.7 for ARCA 15 Year warranty certificate requirements)
Added

2015-12

.3

For conventional design thermoplastic roofing systems, the top of the roof area divider shall extend a minimum distance of 200mm (8") above the finished roof surface.

.4

Where the roof system drainage slopes away on both sides of the roof area divider with a minimum slope of 1:50 (1/4"/ft.), the roof area divider height may be reduced to a minimum distance of 75mm (3") above the finished roof surface.
Revised

2016-01

.5

Roof area dividers may be of single or multi-plate construction and shall be fastened to the roof decking to prevent displacement.

.6

Membrane level drainage openings are not permitted through roof area dividers. Where drainage is required through area dividers, drainage openings shall be installed no lower than 75mm (3") above the primary membrane.

.7

To qualify for an ARCA 15 Year Warranty Certificate, roof area dividers shall be installed so that the enclosed membrane section area does not exceed approximately 1,859 sq.m. (20,000 sq.ft.).
Revised

2016-08

TP-2.2 Perimeters

.1

For conventional design thermoplastic membranes, a metal thermoplastic coated drip edge flashing may be used to finish the perimeter edge of the roofing system.

.2

Where parapets are used they shall extend a minimum height of 75mm (3") above the finished roof surface.

.3

The top surface of the parapet wall shall be sloped towards the roof when the width of the parapet is greater than 100mm (4"). The top of the parapet wall must have wood blocking installed which is capable of providing holding power for nails and/or screws used to secure the metal flashing.

.4

To qualify for an ARCA 15 Year Warranty Certificate, new metal flashing shall be installed at all control joints.
Added

2015-12

TP-2.3 Roof Penetrations

TP-2.3.1 General

.1

Where permitted and when installed in accordance with the application standards, thermoplastic roofing system penetrations may be waterproofed with thermoplastic coated metal gum boxes and flashings, pre-molded pipe boot or field fabricated flashings, curbs or specialty devices designed for this purpose by the membrane manufacturer.
Revised

2010-06

.2

For sheet metal flashing penetrations, the thermoplastic coated horizontal metal flange shall have rounded corners and shall be secured to and be completely supported by wood blocking matching the insulation thickness.

.3

The wood blocking length shall exceed the metal flange width and shall be secured to the structural decking.

.4

Pre-molded pipe boot flashings by the membrane manufacturer may be used to seal, where practical, circular roof penetrations and to seal waterproof flexible service lines when they are supported or secured to prevent collapse of the pre-molded pipe boot flashing.

.5

To qualify for an ARCA 15 Year Warranty Certificate:
  1. All membrane penetrations except roof drains shall be curbed.
  2. New metal flashing shall be installed at all roof penetrations.
Added

2015-12

TP-2.3.2 Curbs

.1

Curb tops shall extend a minimum distance of 200mm (8”) above the finished primary membrane surface.

.2

Curbs may be of wood or metal construction and shall be mechanically fastened to the structural decking. Curbs shall be insulated.

.3

Metal curb tops shall be designed to provide a minimum 50mm (2”) counter flashing overlap.

.4

Exposed penetrations through curbs shall be placed no lower than 200mm (8”) above the finished roof surface.

TP-2.3.3 Plumbing Vent Flashings

.1

Plumbing vents penetrating the roofing system, that are not curbed, may be waterproofed with a conical one piece aluminum flashing, pre-molded pipe boot or field fabricated flashing or a pre-approved specialty device designed for this purpose. (Refer to TP 2.3.1.5.1 for ARCA 15 Year Warranty Certificate Requirement)
Added

2015-12

.2

Spun aluminum vent flashings, when not curb mounted, shall extend a minimum distance of 200mm (8”) above the primary membrane surface, and shall have a minimum of 100mm (4”) wide thermoplastic coated flange. The top surface shall be cleaned to ensure proper adhesion of the membrane flashing. (Refer to TP 2.3.1.5.1 for ARCA 15 Year Warranty Certificate Requirement)
Added

2015-12

.3

When curb mounted, the curb shall be sized so the base flange overlaps and extends down the membrane flashing a minimum distance of 50mm (2”) on all sides. The plumbing vent flashing shall be mechanically fastened to the curb on each side. Do not place fasteners through the horizontal surface.
Revised

2010-06

.4

Where vent extension pipes are required, the base of the extension pipe shall be sealed into the vent stack hub. The interior of the plumbing vent flashing shall be insulated to reduce condensation.

.5

Seal the junction between the base of the neoprene collar and the horizontal surface of the aluminum vent flashing with a composite caulking.
Added

2014-10

TP-2.3.4 Jack, Ventilator, and Gooseneck Flashings

.1

When installed at membrane level, the flashing may not exceed 356mm (14") in diameter or on a side. Each flashing shall incorporate a one piece base flange not less than 100mm (4") nor more than 200mm (8") in width. A flashing sleeve/cone shall extend not less than 200mm (8") nor more than 300mm (12") above the base flange. For gooseneck flashings, the minimum flashing height shall be measured to the throat of the bend. The sleeve connection with the base flange shall be soldered. All other seams, including gooseneck segments, shall be soldered/welded water tight.

.2

The top surface of the thermoplastic coated flange shall be cleaned to ensure the proper adhesion of the membrane flashing.

.3

When curb mounted, the metal base flange shall be sized to over lap and extend down over the curb base flashing a minimum distance of 50mm (2") on all sides. The metal flashing shall be mechanically fastened to the curb on each side. Do not place fasteners through the horizontal flange surface. (Refer to TP 2.3.1.5.1 for ARCA 15 Year Warranty Certificate Requirement)
Added

2015-12

TP-2.3.5 Gum Boxes

.1

Rigid service lines shall be waterproofed using gum boxes.
Revised

2016-01

.2

Only armoured, thermoset-insulated or thermoplastic-insulated flexible service lines are permitted and shall be contained within a curbed enclosure or gum cup. The top 50mm (2”) of the gum cup shall be filled with two-part pourable sealer and the flexible line must be supported until the sealer has cured.
Revised

2016-06

.3

For new construction, gum boxes shall be of one-piece construction incorporating a minimum 100mm (4”) wide continuous horizontal flange with no open corners. Gum box sides shall be sealed and shall extend a minimum distance of 100mm (4”) above the primary membrane surface.

.4

The gum box shall be packed with oakum or other material to contain the sealer. The gum box shall be filled with a minimum 50mm (2”) thick layer of rubberized asphalt sealer or a purable sealer and left crowned to shed water. Plastic cemet is not permitted to fill gum boxes and shall not be used for this purpose.

.5

When re-roofing, gum boxes may be of a two piece construction provided there are no openings when installed and the rubberized asphalt sealer is contained.

.6

When more than one service line occupies a gum box, a minimum separation distance of 25mm (1”) shall be maintained between each service line and the gum box sides.
Revised

2016-01

.7

Three sided gum boxes require minimum 100mm (4") flanges attached to the parapet wall and must be waterproofed with membrane flashing.
Added

2016-01

.8

To qualify for an ARCA 15 Year Warranty Certificate, all membrane penetrations shall be curbed, no gum boxes permitted.
Added

2015-12

TP-2.3.6 Pre-Molded Pipe Boot Flashings

.1

Pre-molded pipe boot flashing may be used, where practical, to seal circular roof penetrations and waterproof flexible service lines.

.2

Waterproof flexible service lines, such as Teck 90 P.V.C. jacketed electrical cable, shall be supported or secured to prevent collapse of the pre-molded pipe boot flashing.

.3

Pre-molded pipe boots may be cut to a height no lower that 100mm (4”) above the primary membrane.

.4

The pipe boot flange shall be adhered to the primary membrane in accordance with the manufacturer’s application requirements.

.5

Do not overlap or trim pipe boot membrane flashing flanges.

.6

The upper pipe boot flashing termination shall be sealed to the circular roof penetration/waterproof flexible service line with a continuous band of sealant and a properly tightened stainless steel pressure clamp.

TP-2.3.7 Fall Arrest Anchors

.1

ARCA Warranty Ltd. assumes no liability relative to the supply and installation of fall arrest anchors.

.2

The Warranty Certificate does not include warranty of the fall arrest anchor system or its performance except as it relates to the watertight integrity of the roof membrane flashing seal around the anchor flashing.

.3

ARCA Warranty Ltd. recommends that a professional structural engineer, licensed in Alberta, design the fall arrest anchor system. Installation, drawings, specifications and conformance to current building and safety codes shall be included in the professional engineer’s scope of work.

.4

Fall Arrest Anchors shall be waterproofed in accordance with Sections TP 2.3.5. and TP 2.3.6.
Revised

2016-06

TP-2.3.8 Roof Mounted Photovoltaic Equipment

.1

Enclosed roof sections that include photovoltaic equipment shall be independently drained and shall have positive drainage with a minimum slope of 1:50 (2%).

.2

The total area of roof mounted photovoltaic equipment shall occupy no more than 50% of the total roof area.

.3

Only rack-mounted photovoltaic systems secured directly to the structural roof deck will be approved when installed in accordance with ARCA Roofing Application Standards.

.4

Accessibility to roofing components shall be incorporated into the photovoltaic equipment design.
  1. A minimum clearance of 3000mm (10') shall be provided around the perimeter of the roof area.
  2. A minimum clearance of 1200mm (4') shall be provided between rows of photovoltaic arrays.
  3. A minimum clearance of 1200mm (4') shall be provided to access all roof penetrations. There shall be a minimum 1200mm (4') clearance on all sides of each roof penetration.
  4. A minimum clearance of 300mm (12") shall be provided beneath the photovoltaic equipment to permit installation of the roofing system. Equipment supports shall be designed by a structural engineer and shall conform to the Alberta Building Code.

.5

Roof Warranty coverage of this section applies to commercial buildings for leak repairs on roof systems for five (5) or ten (10) year terms only. The cost to remove and replace the photovoltaic equipment to facilitate access to the roof membrane for investigation and repair of workmanship related leaks is not included and is the responsibility of the building owner.
Added

2017-08

TP-2.4 Roof Drains

TP-2.4.1 General

.1

The Warranty Certificate does not include warranty of the roof drainage system except as it relates to the watertight integrity of the roof membrane flashing seal around the drain assembly.

.2

Provisions for emergency drainage is recommended in all instances and is a requirement when control flow drains are incorporated into the roof drainage system.

.3

All roof drain assemblies, except scuppers, shall incorporate a clamping ring.

.4

To qualify for an ARCA 15 Year Warranty Certificate, each self-contained roof area shall be independently drained using internal roof drains and plumbing systems. Water from an elevated roof shall not be discharged directly to a lower roof except where emergency scuppers are required.
Added

2016-08

TP-2.4.2 Cast Drains

.1

A heavy bead of the membrane manufacturer's approved water cut-off mastic shall be used to seal all cast drain assemblies.

.2

The top hopper flange of the roof drain must be approximately 12.7mm (½”) below the surface of the primary membrane.

TP-2.4.3 Retrofit Drains

.1

Retrofit drains may be used for roof replacements (re-roofing) when cast drains are not practical. Retrofit drains shall be of thermoplastic coated spun aluminum or copper construction, with a minimum flange width of 100mm (4”). The flange shall be set in a bed of a compatible sealant and the top surface shall be to ensure proper adhesion of the membrane flashing. The drain size shall match that of the existing drain line. The retrofit drain sleeve shall incorporate a seal to prevent back flow from the existing drain line.

.2

Sheet metal drop drains shall only be used for exterior drainage locations, such as through an overhang. A minimum 100mm (4") wide thermoplastic coated flange shall be soldered to the pipe sleeve and shall be set in a bed of a compatible sealant. The drain flange shall be continuously supported by wood blocking matching the insulation thickness. The top surface of the flange shall be cleaned to ensure proper adhesion of the membrane flashing.

TP-2.4.4 Scupper Drains

.1

Scupper drains permit roof drainage through the perimeter building elements, such as parapets. Scupper drains may also serve as emergency over flow outlets. Scuppers may be open or through-wall type fabricated with or without an exterior hopper. When serving as primary drainage, the scupper shall be set so that the scupper apron is at or below primary membrane level.

.2

Scuppers shall be fabricated from minimum 26 gauge thermoplastic coated galvanized sheet metal. Scupper flanges must extend a minimum distance of 100mm (4”) over the primary membrane and wall opening. Sheet metal flanges shall be set in a bed of a compatible sealant. The tops of the flanges shall be cleaned to ensure proper adhesion of the membrane flashing. The horizontal scupper flange shall be continuously supported by wood blocking matching the insulation thickness.

.3

Through wall scuppers shall be four (4) sided to cover the upper scupper opening with sheet metal. The scupper opening shall be waterproofed in accordance with good roofing practice.

.4

Where control of drainage is required, the scupper assembly may include an exterior hopper and an attached down pipe.
Added

2010-06