Is 8 in overkill for a normal seam?

Usually, yes. A standard panel seam or fastener row is cheaper in 2 or 4 in. Eight inches earns its place at transitions, wide bases and joints that are no longer flat.

How much does a case cover?

Three rolls of 50 ft, so 150 linear feet before end laps. On a job with long transitions that goes quickly, so send the lengths with your request.

Can I use it instead of fabric at a flashing?

They do different jobs. Tape is a dry seal under the system; fabric is bedded into a wet coat and builds film with it. The manufacturer's product data sheet for the coating states which detail takes which.

Does anything have to go over it?

On a coating project the system coats over it. If you want a taped detail that is listed as needing no coat over it, the fleece-backed MS hybrid bonding tapes KST058004 and KST058006 are the ones to look at.

Can it go on a Hypalon roof?

Yes. The butyl seam tape is listed for EPDM and CSPE Hypalon roofs, coated over with the elastomeric the same day. It is the only detail product in our catalogue the manufacturer lists for Hypalon: none of our cartridge sealants names it, so on Hypalon the sealant is confirmed with the manufacturer's technical service and an adhesion test before the order. Tell us the membrane type.

What is the lead time?

Stocked cases ship in 1 to 3 business days. If the 8 in width is off the shelf when your order lands, it is brought in on a 1 to 2 week lead.

Reinforcing fabrics & seam tapes

KST020808 Uniflex Butyl Seam Tape, 8 in × 50 ft

Seam tape
8 in × 50 ft
Sold by the case

The widest butyl roll in the Uniflex range, 8 in across and 50 ft long, three rolls to the case. It is bought for broad joints, material transitions and wide flashing bases where a narrower tape would not reach sound substrate on both sides.

Key benefits

Eight inches reaches sound substrate on both sides of a wide or irregular joint
Self-adhering butyl rubber, laid dry under pressure, with nothing to mix and no wet coat to time
Three 50 ft rolls per case, 150 linear feet of wide detail work per box
Listed for seams, flashings, penetrations and other roof details in the Uniflex system
The narrower 2, 4 and 6 in rolls are the same butyl, so one order can cover every detail width on the roof

Priced per project

Send the quantity and the delivery ZIP. We reply within one business day.

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In stock Confirm the quote, and your order ships in 1–3 business days from confirmation.

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Overview

The 8 in roll is the one you buy for the awkward joints. A tie-in between metal and modified bitumen, a wide parapet base, a joint that has been patched twice already and no longer sits flat: all of them need tape bearing on sound material well back from the joint itself. KST020808 gives you eight inches of Uniflex self-adhering butyl to work with, 50 ft to the roll, three rolls to the case.

It is the same butyl as the rest of the family, so it behaves the same way, bonding under roller pressure rather than cure time. The economics are what change: 150 linear feet per case instead of 600 in the 2 in roll, which is why most jobs order this width only for the details that need it and cover the routine seams with the 4 in and 6 in rolls.

Application

Prepare a clean, dry, sound surface across the full width the tape will cover, not just over the joint.
Prime by substrate where the system calls for it, with a metal primer, a concrete primer or, on EPDM only, the wash primer.
Sort out the detail first. Mechanical repairs, refastening and any patching happen before the tape goes on.
Lay the tape without stretching it, roll the whole width down firmly, and lap roll ends by the amount the data sheet gives.
Follow the manufacturer’s product data sheet for surface preparation, application temperature and what may go over the tape and when.

Ordering

KST020808 is sold by the case of three 8 in × 50 ft rolls. Stocked cases ship in 1 to 3 business days, and off-shelf widths are ordered in on a 1 to 2 week lead. Pallet quantities, and the pails, drums or totes traveling with them, go through the quote form as a freight shipment; send the part numbers, quantities, site ZIP and your dates. Every price is quoted per project.

Where it's used

Material transitions

Tie-ins where metal meets modified bitumen, or an old membrane meets a new section, and the joint needs wide dry coverage before the coats.
Wide flashing bases

Parapet and wall bases on larger details, where the tape carries up the vertical leg and well out onto the deck.
Opened and irregular joints

Joints that have moved, been patched before, or sit in a surface that is no longer flat, where bearing area matters more than roll economy.
Large curb perimeters

The base joint around rooftop units and big equipment curbs, taped ahead of the field coats.
Wide gutter seams

Long lapped seams and outlet joints in oversized gutters and box gutters, closed dry before any coating work.

Specifications

Specifications: KST020808 Uniflex Butyl Seam Tape, 8 in × 50 ft
Manufacturer	Sherwin-Williams (Uniflex line)
Part number	KST020808
Color	Not listed in our catalog data; the manufacturer's product data sheet states it
Pack sizes	8 in × 50 ft roll

Performance
Technology	Self-adhering butyl rubber tape
Roll size	8 in × 50 ft
Case quantity	3 rolls per case
Recommended substrates	Roof seams, flashings, penetrations and other roof details, including EPDM and CSPE Hypalon roofs
Role in the system	Self-adhering detail reinforcement that goes down dry before the coating

Ordering
SKU	CY-KST020808
Sold by	Case
Lead time	In stock · 1–3 business days
Warranty	Goods are warranted to match their description and to be free of manufacturing defects when delivered; any manufacturer system warranty is issued by the manufacturer under its own terms

Delivery and lead time

Ships in 1–3 business days from order confirmation. Your quote states the delivery window before you commit.
Pails, rolls and cartons ship by parcel or pallet; drums and totes by freight to your site. Tell us about lift-gate, access or unloading needs when you ask for a quote.

Shipping & returns

How to order

Send the quantity, the site ZIP and your timing.
A person sends one written quote with the delivered price and the ship window. We reply within one business day.
Confirm the quote, and your order ships in 1–3 business days from confirmation.

Request a quote

Questions

Is 8 in overkill for a normal seam?: Usually, yes. A standard panel seam or fastener row is cheaper in 2 or 4 in. Eight inches earns its place at transitions, wide bases and joints that are no longer flat.
How much does a case cover?: Three rolls of 50 ft, so 150 linear feet before end laps. On a job with long transitions that goes quickly, so send the lengths with your request.
Can I use it instead of fabric at a flashing?: They do different jobs. Tape is a dry seal under the system; fabric is bedded into a wet coat and builds film with it. The manufacturer's product data sheet for the coating states which detail takes which.
Does anything have to go over it?: On a coating project the system coats over it. If you want a taped detail that is listed as needing no coat over it, the fleece-backed MS hybrid bonding tapes KST058004 and KST058006 are the ones to look at.
Can it go on a Hypalon roof?: Yes. The butyl seam tape is listed for EPDM and CSPE Hypalon roofs, coated over with the elastomeric the same day. It is the only detail product in our catalogue the manufacturer lists for Hypalon: none of our cartridge sealants names it, so on Hypalon the sealant is confirmed with the manufacturer's technical service and an adhesion test before the order. Tell us the membrane type.
What is the lead time?: Stocked cases ship in 1 to 3 business days. If the 8 in width is off the shelf when your order lands, it is brought in on a 1 to 2 week lead.