Is 4 in the width to buy if I only buy one?

For most metal and single-ply detail work, yes. It crosses a typical seam with margin and still handles pipe boots and curb corners. Narrow fastener rows are cheaper in 2 in and open joints want 6 or 8 in.

Does the coating go over this tape?

On a coating job it does. Butyl seam tape is listed for details under the system. The fleece-backed MS hybrid bonding tapes, KST058004 and KST058006, are the ones listed as not needing a coat over them.

Can it be used on its own as a repair?

It is sold as detail reinforcement for the Uniflex system, and the manufacturer's product data sheet is what defines where it may be left exposed. For repairs outside a coating project, look at the bonding tapes or the sealants.

How many cases for 900 feet of seam?

Six rolls of 50 ft is 300 linear feet per case, so 900 feet is three cases plus an allowance for end laps and waste. Send the seam lengths and the quote states the case count.

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.

Stocked cases go out in 1 to 3 business days. If the width is not on the shelf when the order lands, it is ordered in and takes 1 to 2 weeks.

Reinforcing fabrics & seam tapes

KST020804 Uniflex Butyl Seam Tape, 4 in × 50 ft

Seam tape
4 in × 50 ft
Sold by the case

The width most crews order first. Four inches of self-adhering Uniflex butyl on a 50 ft roll, six rolls to the case, sized to cross a standing seam or a side lap with margin on both sides and still be quick to roll down.

Key benefits

Four inches crosses a standing seam or a side lap with material either side of the joint
Self-adhering butyl rubber, applied dry, so the detail is finished before the coating crew arrives
Six 50 ft rolls per case, 300 linear feet of seam work in one box
Listed for seams, flashings, penetrations and other roof details in the Uniflex system
Stocked in all four widths, so a job can carry 2, 4, 6 and 8 in on the same order

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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Shipping & returns

Overview

Four inches is the width that ends up on most orders. It is wide enough to cross a standing seam, a side lap or a gutter joint with butyl either side of the joint, and narrow enough to roll down quickly and to fold around a boot or a curb corner. KST020804 is that width in Uniflex self-adhering butyl, 50 ft to the roll and six rolls to the case.

Because the tape goes on dry, detail work stops being a bottleneck. A crew can tape the seams on a windy afternoon and coat the field the next morning, rather than three-coursing every joint in a wet base coat. The same butyl runs narrower as KST020802 at 2 in and wider as KST020806 and KST020808, and the polyester fabrics cover the details that want film build instead of tape.

Application

Work on a clean, dry, sound surface. Take off loose coating, rust scale and dirt, and degrease where the panel has been oily.
Prime where the system calls for it, choosing the primer by substrate: a metal primer on panels, the wash primer on EPDM only. TPO, PVC and Hypalon are pressure washed instead.
Detail before field. Tape the seams, laps and penetrations first, reinforce the wider flashings with fabric, then coat.
Press the tape down along its full length with a roller and lap the roll ends. Butyl needs pressure, not time, to bond.
Follow the manufacturer’s product data sheet for preparation, application temperature and what may go over the tape and when.

Ordering

KST020804 ships by the case of six 4 in × 50 ft rolls. Stocked cases leave in 1 to 3 business days; a width that is off the shelf is ordered in on a 1 to 2 week lead. Pallet quantities and any drums or totes on the same order move as freight, priced through the quote form with the part numbers, quantities, site ZIP and your dates. Prices are quoted per project rather than printed.

Where it's used

Standing seams and side laps

The seam line on a metal panel roof, taped along its length before the base coat so the joint is closed and the coating only has to build film over it.
Pipe boots and curb corners

Boots, sleeves and the corners of small curbs, where a 4 in strip folds and dresses into the flat without a lot of cutting.
Gutter and downspout joints

Lapped joints in existing gutters and at downspout outlets, closed dry before any coating or sealant work.
Wall and base flashings

The base angle at parapets and walls on smaller details, where 4 in reaches up the vertical and out onto the deck.
Detail work under a coating system

Any roof detail listed for tape rather than fabric, taped ahead of the field coats so the crew keeps moving.

Specifications

Specifications: KST020804 Uniflex Butyl Seam Tape, 4 in × 50 ft
Manufacturer	Sherwin-Williams (Uniflex line)
Part number	KST020804
Color	Not listed in our catalog data; the manufacturer's product data sheet states it
Pack sizes	4 in × 50 ft roll

Performance
Technology	Self-adhering butyl rubber tape
Roll size	4 in × 50 ft
Case quantity	6 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-KST020804
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 4 in the width to buy if I only buy one?: For most metal and single-ply detail work, yes. It crosses a typical seam with margin and still handles pipe boots and curb corners. Narrow fastener rows are cheaper in 2 in and open joints want 6 or 8 in.
Does the coating go over this tape?: On a coating job it does. Butyl seam tape is listed for details under the system. The fleece-backed MS hybrid bonding tapes, KST058004 and KST058006, are the ones listed as not needing a coat over them.
Can it be used on its own as a repair?: It is sold as detail reinforcement for the Uniflex system, and the manufacturer's product data sheet is what defines where it may be left exposed. For repairs outside a coating project, look at the bonding tapes or the sealants.
How many cases for 900 feet of seam?: Six rolls of 50 ft is 300 linear feet per case, so 900 feet is three cases plus an allowance for end laps and waste. Send the seam lengths and the quote states the case count.
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.
When does it ship?: Stocked cases go out in 1 to 3 business days. If the width is not on the shelf when the order lands, it is ordered in and takes 1 to 2 weeks.