Flex TPO PLUS Adhered roof membrane User Manual

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

FLEX TPO PLUS

ADHERED ROOF MEMBRANE

INSTALLATION GUIDE

This guide is intended to be a point of reference in assisting the Flex Authorized Applicator with installing
the Flex TPO Plus Adhered 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.

E. Lightweight Insulating Concrete: Flex FB membranes may be adhered directly to

approved cellular or perlite insulating concrete. The insulating concrete deck must have a

minimum compressive strength of 225 psi.

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 the 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 the 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 Adhered Membrane Placement and Securement:

Method 1 Plain Back TPO Membrane

A. The substrate must be clean and dry prior to installing the Flex TPO Plus Membrane.
B. Position Flex Roof Membrane over the acceptable substrate. It is recommended to place

the sheets in a manner to install the membrane in the longest lengths possible. It is also

good practice to lay out the membrane sheets in a shingle fashion so that the seams are not

placed in position to buck the flow of water to the drain.

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C. Fold the one end of the sheet back so half the underside of the membrane is exposed.

Apply Flex TPO Bonding Adhesive to the substrate and the exposed underside of the

membrane. The adhesive is applied with a medium nap paint roller at an approximate

coverage rate of 60 square feet per gallon (includes coverage on both membrane and

substrate). Allow the adhesive dry until tacky.

D. Pull and roll the membrane into the adhesive without wrinkling the membrane.
E. Brush down the adhered membrane immediately with a soft bristle push broom to remove

any air pockets.

F. Repeat the process with the other half of the sheet.
G. Position the adjacent membrane sheet over the selvedge edge of the underlying sheet. The

edge must over lap the length of the underlying membrane a minimum of 3” to insure an

adequate 1.5” hot air weld. Roll ends must over lap the underlying membrane a minimum

of 6” and the seam hot air welded. Do not allow adhesive to be applied to the seaming

areas.
H. Hot air weld the seams with an automatic or hand held hot air welder, properly welded

seams are a minimum of 1.5” in width. The membrane must be welded the same day it is

installed.

Method 2 Fleece Back TPO Membrane

A. The substrate must be clean and dry prior to installing the Flex TPO Plus Membrane.
B. Position Flex Roof Membrane over the acceptable substrate. It is recommended to place

the sheets in a manner to install the membrane in the longest lengths possible. It is also

good practice to lay out the membrane sheets in a shingle fashion so that the seams are not

placed in position to buck the flow of water to the drain.
C. Fold the one end of the sheet back so half the underside of the membrane is exposed.

Apply Flex TPO WB Substrate Adhesive to the substrate only. The adhesive is
applied with a medium nap paint roller or a 1/8” notched squeegee at an approximate
coverage rate of 100 -120 square feet per gallon. Adhesive coverage may vary
depending on the substrate.

D. The TPO Membrane is rolled directly into the wet adhesive.
E. Brush down the adhered membrane immediately with a soft bristle push broom to remove

any air pockets.

F. Roll the membrane with a heavy roller (minimum 100 - 150 lbs.).
G. Repeat the process with the other half of the roll.
H. Position the adjacent membrane sheet over the selvedge edge of the underlying sheet. The

edge must over lap the length of the underlying membrane a minimum of 3” to insure an

adequate 1.5” hot air weld. Do not allow adhesive to be applied to the seaming areas.
I. Roll ends are cut to butt against each other. The joint is covered with Flex 6” TPO Trim

Strip and completely hot air welded to the field membrane.
J. Hot air weld the seams with an automatic or hand held hot air welder properly welded

seams are a minimum of 1.5” in width. The membrane must be welded the same day it is

installed.

2.01 Field Membrane Securement:

A. Hot air weld the seam and continue in sequence installing the remainder of the

sheets across the roof area.

B. Mechanical securement must be provided at the perimeter edge of each roof level,
roof section, expansion joint or roof divider.

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C. Cold adhesive installations or installations in high velocity wind zones may require
additional securement at all roof penetrations and curbs, adjacent walls and at any
angle change where the slope exceeds 2:12.
D. All seams must be completed by hot air welding the same day they are installed.

Thoroughly probe the seams with a seam probe and repair any voids or defects
discovered.

3.0 Flashing:

A. General Flashing Conditions:

Flex Reinforced Flashing Membrane is to be installed for the flashing of parapet
walls, roof equipment curbs, expansion joints and roof dividers, and for most other
roof detail flashing areas. Flex non reinforced flashing membrane may be used for

those areas where the use of pre-formed accessories cannot be installed such as certain pipe

penetrations, corners, and scuppers details.

1. Re-roofing Flashing Conditions. Existing flashings must be removed prior to

installing the new Flex Flashing Membrane.

2. Termination Bar, surface mounted reglet, or surface mounted counter
flashings must be installed directly to the wall surface.

B. Application:

Adhere the flashing membrane to walls, curbs and other vertical surfaces with Flex

Flashing Adhesive. The Flashing Adhesive is applied to both the membrane and the

surface to which it is bonded. The coverage rate is dependent on the type of substrate but

should average approximately 60 square feet per gallon for both the membrane and the

substrate. The Flashing Adhesive is allowed to dry until it is tacky and the flashing

membrane is rolled into the adhesive.

1. Complete all seams of the flashing membrane by the hot air welding
method.

2. Refer to the current Flex Membrane installation for applicable detail
requirements.

4.0 Accessories:

A. Walkway Pads

1. Install walkway pads in those locations as designated in the specifications.

2. Thoroughly clean and prepare the area of the roof membrane that is to be hot air

welded to the walkway pad.

3. The Flex Walkway Pad is installed in maximum lengths of 10’.

4. Position sections of the walkway pad to leave a space between adjacent sheets
approximately 2” wide.

5. Do not cover field seams with the Walkway Pad. Position the pads to leave
minimum 4” wide area exposed at the field seams.

6. Hot air weld all four sides of the walkway pad to the field
membrane.

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B. Pavers

1. Either a protection sheet of Flex MF/R Flashing Membrane or Flex
180N Geotextile Separation Layer must be installed under all

concrete paver blocks.

5.0 Night Seal:

A. The new roof membrane must be sealed at the end of each work day to prevent water

infiltration.
B. The membrane may be temporarily sealed by securing the down slope edge with roof
cement, hot asphalt, spray urethane foam or similar water blocking materials.

C. Embed the membrane into the sealant product and insure continuous contact.
D. The following day, when the installation is resumed, cut away and discard the

membrane where the night seal was applied before continuing with installing the
adjoining section.

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