Flex Thermoplastic Mechanically Attached Roof Membrane User Manual

Flex Membrane International Corp. 2670 Leiscz’s Bridge Road,Suite 400, Leesport, PA 19533 Phone [phone] Fax: [phone]

FLEX MEMBRANE THERMOPLASTIC

MECHANICALLY ATTACHED ROOF MEMBRANE

INSTALLATION GUIDE

This guide is intended to be a point of reference in assisting the Flex Authorized Applicator with
installing the Flex Thermoplastic Roof System in accordance to the basic requirements of current Flex
Details and Specifications for acceptance of the installation for a roof warranty application.
The installer should always refer to the project specifications for details and application requirements
for each unique roof system installation.

1.0 Substrate Preparation

Defects in the substrate surface must be reported and documented to the Building Owner’s
Representative for assessment. The roofing contractor shall not proceed with the roof system
installation until the defects in the substrate have been corrected.

A.) Recover or Retrofit Roofing Applications: The project specifier shall identify
damaged or wet insulation areas. The insulation as indicated shall be cut out and
removed from the roof area. The removed insulation shall be replaced with new
insulation of the proper size to fill the space (flush with existing surface±1/4”)
and obtain a relatively smooth surface acceptable for the installation of the new
roof system.

B.) Existing Single Ply Roof Membranes: If the existing membrane is to be left in place

it must be cut into sections no larger than 100 square feet per each section.
All flashing must be removed at the perimeter edge, roof drains and roof penetrations.

C.) Gravel Surfaced Built Up Roofing: The loose gravel must be removed either by
vacuuming or power brooming. The surface must be leveled to prevent the
insulation or recover board from bridging.

D.) All Projects: The substrate must be smooth and relatively even without high spots or

depressions. Any accumulated water, ice or snow must be removed to prevent
the absorption of moisture in the new roofing components and roofing system.
The substrate shall be clean and free from debris and any other foreign material.

1.1 Vapor or Air Barrier Installation

Install the barrier in accordance with the manufacturer’s written instruction and the
project specifications for the installation of the specified product.

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1.2 Wood Blocking

A.) Install wood blocking as indicated by the project specifications and in accordance with

current Flex Details and Specifications. Blocking is always required at roof edges and roof
penetrations.

B.) The wood blocking is installed so the top of wood is flush with the top surface of the roof

insulation or cover board.

C.) The wood blocking width is to exceed the width of flange to be attached to the blocking.
D.) The securement of the blocking shall be in a manner to meet or exceed the local building

code requirements and the wind uplift pressure resistance required in the project
specifications.

1.3 Insulation/Recover Board

A.) Only install as much insulation or recover board that can be covered with roofing

membrane and be made watertight in the same day.

B.) Insulation/recover boards are to be installed butted together with no gaps larger than ¼” in

the joints acceptable. Gaps in the joints larger than ¼” must be filled.

C.) Top surfaces of the insulation/recover boards are to be aligned and flush with each other.

Differences in the top edge alignment greater than 1/8” are not acceptable.

D.) Insulation/recover board that is to be installed in multiple layers must have the joints

staggered between each layer.

E.) Insulation /recover board is mechanically attached to the roof deck with Flex Fasteners and

Insulation Plates.

F.) Insulation/recover board is adhered to an approved roof deck with Hot Steep Asphalt or

Flex Insulation Board Adhesive.

1.4 Restrictions

A.) Precautions must be taken when installing materials with Hot Steep Asphalt in

temperatures lower than 40°F. The hot asphalt must be delivered to the application point at
the asphalt manufacturer’s recommended EVT.

B.) Adhesives and sealants must be protected when ambient temperatures are lower than 40°F.

Insulated, heated storage boxes must be provided to store the products on the roof for
temporary storage.

C.) Insulation and underlayment must be stored in a manner to keep the products dry and

protected from the elements. The products must be stored off the roof surface on skids and
covered with a breathable watertight cover.

2.0 Mechanically Attached Membrane Placement and Securement

A.) The substrate must be clean and dry prior to installing the Flex Roof Membrane.
B.) The type of Flex fastener is dependent upon the membrane width and the deck type. The

specific type of approved fastener is found in the components section of Flex’s Technical
Manual. If the proper fastener cannot be determined, contact the Flex Technical Service
Department.

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