Square Vent Master Flash

Square Vent Master Flash is a flashing from Aztec Washer Company's Master Flash line, designed for square vents on metal roofs. It comes in two versions with different uses and sizes.

The Square Vent Master Flash is designed for retrofit applications. It is made of black EPDM rubber on an aluminum base in two sizes, #1 and #2, and comes with snap rivets and a cable tie. The Multi-Flash Square Vent Master Flash is designed for both standard and retrofit applications. It is made in three sizes, #1, #2 and #3, in black EPDM rubber or high-temperature red silicone on a flexible aluminum base.

Both versions are made for metal roofs. The retrofit use is for existing pipes and vents that need a wrap-around installation or are hard to reach, and in both versions the sleeve is flexible and absorbs vibration and pipe movement caused by expansion and contraction.

The retrofit version is made in two sizes, with a pipe fit from 2 1/4 to 5 1/2 in. (57 to 139 mm) and a base from 8 to 15 3/4 in. (203 to 400 mm). Both sizes are black EPDM.

• #1: top opening 2 1/2 in. (63 mm); cut to suit pipes 2 1/2 to 4 in. (63 to 101 mm); base 8 in. (203 mm); part RF101BP-SQ.
• #2: top opening 2 1/4 in. (57 mm); cut to suit pipes 2 1/4 to 5 1/2 in. (57 to 139 mm); base 15 3/4 in. (400 mm); part RF201BP-SQ.

Trim steps for the #1 are 2 1/2, 3 1/8 and 4 in. (63, 79 and 101 mm), and for the #2 they are 2 1/4, 3, 4, 5 and 5 1/2 in. (57, 76, 101, 127 and 139 mm).

The Multi-Flash version is made in three sizes. Each has a closed top and both a standard and a retrofit fit. Part numbers ending BA are black EPDM and those ending RA are red silicone.

• #1: standard fit closed to 5 in. (0 to 125 mm); retrofit fit 3/4 to 4 1/2 in. (20 to 115 mm); base 8 in. (203 mm); parts MFSQ101BA and MFSQ102RA.
• #2: standard fit closed to 10 in. (0 to 254 mm); retrofit fit 7/8 to 9 5/16 in. (22 to 237 mm); base 14 1/4 in. (361 mm); parts MFSQ201BA and MFSQ202RA.
• #3: standard fit closed to 19 1/8 in. (0 to 487 mm); retrofit fit closed to 17 1/2 in. (0 to 444 mm); base 24 3/4 in. (628 mm); parts MFSQ301BA and MFSQ302RA.

The base range across the three sizes is 8 to 24 3/4 in. (203 to 628 mm). For standard use, the pipe-size steps run from 3/4 to 5 in. in eight steps on the #1, from 7/8 to 10 in. in ten steps on the #2 and from 11 to 19 1/8 in. in eight steps on the #3.

The retrofit version is black EPDM rubber, made for resistance to ultraviolet light and ozone. Its aluminum base is designed to mold to most panel configurations and roof pitches regardless of pipe location, and snap rivets and a cable tie come with it for installation and reinforcement.

The Multi-Flash version is black EPDM rubber or high-temperature red silicone, both compounded for resistance to weathering from ozone and ultraviolet light. It has a flexible aluminum base and includes a stainless-steel gripper and a plastic zip tie. A lip on the flashing is designed to hold the zip tie in retrofit use, and cut lines are marked for multiple pipe sizes.

The EPDM of both versions, and the red silicone of the Multi-Flash version, are tested to these values:

• Ozone resistance: 70 hours at 500 pphm for both compounds.
• High temperature, intermittent: EPDM +275°F (+135°C); silicone +500°F (+260°C).
• High temperature, continuous: EPDM +212°F (+100°C); silicone +437°F (+225°C).
• Low temperature: EPDM -67°F (-55°C); silicone -101°F (-74°C).
• Maximum compression set: EPDM 25%; silicone 50%.

The pipe size is found in the size table and the flashing is trimmed along the outline for it, with the opening cut at least 20% smaller than the pipe's outside diameter. On steep roofs or deep corrugations, the next size up is used. Master Seal bonded washers and fasteners are set 1 to 1 1/2 in. apart around the entire base.

The Multi-Flash version follows a standard sequence of measure and trim, slide, form, seal and complete, using fasteners, washers, a zip tie, snips or scissors, a measuring tape, a marker or pencil and sealant. The retrofit version is wrapped around the vent, fastened and sealed, and finished with a zip tie. Its materials add a gripper and pliers to that list.

The Multi-Flash version has a 25-year warranty in EPDM rubber and a 35-year warranty in silicone. The retrofit version has a 20-year EPDM rubber warranty.

Related flashings in the Master Flash range include Fire-Blox, the Universal Retrofit, the Roof Vent Sealing Adapter Multi-Flash, the Mini-Port, Master-Flex, the Electrical Mast Connection, the End Cap, the Fix-A-Flash and the 35 Year Master Flash.