Does Silicone44 need a base coat?

No. Uniflex's silicone specifications put Silicone44 KST044300 straight over the prepared roof with no acrylic base coat under it; the acrylic base coats belong to the acrylic systems. Some roofs need a primer: the rust-inhibitive primer KST034520 on rusted metal, the Bond-It wash primer KST038620 on EPDM, and Uniflex's Bleed Blocker Primer on asphalt that may bleed through, which we do not stock. Foam, cured concrete, weathered TPO and PVC and sound existing coatings take it directly.

How is the adhesion test done?

A small patch of Silicone44 with a strip of fabric embedded in it is left three days, then pulled. Uniflex looks for at least 2 lb per inch; a lower result goes to Uniflex, which decides the primer. Every silicone job gets one, and more of them where the roof is worn, shaded, previously coated or holds water.

Will it fix ponding water?

No coating fixes drainage. Silicone44 is the Uniflex coating made for areas where water stands, but Uniflex's silicone specifications still expect at least 1/4 in per ft of slope and working drains, and water that stands for long means more inspection, cleaning and recoating over the years. Uniflex's Slope Builder KST0SLPBD builds up low areas, but no silicone specification names it under Silicone44, so under silicone the adhesion test and Uniflex decide.

Can it go on a Hypalon roof?

No Uniflex silicone document covers Hypalon (CSPE). A Hypalon roof that drains takes the single-ply acrylic system: pressure wash, the single-ply base coat KST041321, then an acrylic finish coat. For a Hypalon roof that holds water, send us the roof: the primer under silicone has to come from Uniflex in writing, after an adhesion test.

Is Silicone44 a water-based coating?

No. It is a silicone rubber coating. The acrylic elastomerics elsewhere in the range are the water-based products; this one is not. The manufacturer's product data sheet states how it is handled, applied and cleaned up, and the safety data sheet covers storage and transport.

Do you apply the coating?

No. We stock the materials and ship them, and application is the contractor's work, done to the manufacturer's product data sheet. We can arrange a drone moisture scan of the roof before anything is coated, and we work with a network of installers, roofing contractors who apply these systems, and can introduce you to one anywhere in the US.

What about the system warranty?

Sherwin-Williams offers UNIGUARD system warranties of 10 or 15 years when one of its authorized contractors applies the system. The warranty is the manufacturer's, issued under its own terms; we supply the materials, and the goods are warranted to match their description.

Why does the data sheet say 44-300?

44-300 is the manufacturer's product code and KST044300 is the same coating written as a part number; the order lines are KST044300-20 for the pail and KST044300-27 for the drum. The quote states the part number, the pack size and the quantity against the current data sheet, so a number read off an old spec never turns into a wrong pallet.

Elastomeric & silicone finish coats

KST044300 Uniflex Silicone44 Rubberized Silicone Roof Coating, White

Silicone finish coat
Sold by the pail

Silicone44 KST044300 (product code 44-300) is the white silicone finish coat in the Uniflex range and the one made for areas where water stands. Uniflex puts no base coat under it: it goes over the prepared roof, with a primer only where the roof type calls for one. Stocked in 5-gallon pails, with drums quoted.

Key benefits

No base coat: Uniflex puts Silicone44 straight over the prepared roof, with a primer only where the roof type calls for one
The Uniflex coating made for areas where water stands; it does not fix drainage, so slope and drains still come first
Order by KST044300-20 for the 5-gallon pail or KST044300-27 for the 55-gallon drum; drums are quoted and move by freight
Supplier-stated elongation, tensile strength, tear resistance, permeance and SRI figures sit on the spec table, each labeled as the supplier's
The same coating comes in gray as Silicone44 KST044320, so a crew can run two colors and see its own passes

Priced per project

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

Request a quote Ask a question about this product

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

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Shipping & returns

Overview

Silicone44 is the silicone finish coat in the Sherwin-Williams Uniflex range, and this is the white: part number KST044300 (product code 44-300). It is the Uniflex coating made for areas where water stands, and it goes on without a base coat. Uniflex’s silicone specifications put it straight over the prepared roof, with a primer only where the roof type calls for one; the acrylic base coats in this catalogue belong to the acrylic systems, not under silicone. The gray is Silicone44 KST044320, the same coating in a second color.

What goes under it depends on the roof:

Metal: wash; tighten or replace fasteners; fasten any lap open more than 1/8 in; prime every rusted area with the rust-inhibitive primer KST034520 and let it cure; stripe the end laps, fastened seams and ridge-cap laps with Silicone44; then coat the field. On factory-finished (Kynar) panels an adhesion test decides whether any primer is needed, so send us the roof.
EPDM: repair and wash; clean with the Bond-It wash primer KST038620, rinse and let it dry; seal open seams and flashings with the black MS hybrid sealant KST058310; coat. New, unweathered EPDM takes a different primer, so ask us.
TPO and PVC: repair and wash; run the adhesion test; coat directly, with no primer on weathered membrane and no base coat. Seal open seams and flashings with KST058310, whose sheet lists aged TPO and PVC; new TPO or PVC needs a primer first, so ask us. If the test comes in low, Uniflex names the primer for that roof.
Smooth BUR, modified bitumen and granulated cap sheet: repair and wash; where the asphalt is newer or likely to bleed through, Uniflex’s Bleed Blocker Primer goes first. We do not stock it, so ask for it on the quote form. Seal seams and flashings with KST058310, then coat. Granulated cap sheets take more coating than smooth surfaces.
Sprayed polyurethane foam: cut out and replace wet or damaged foam, run the adhesion test, and coat directly.
Concrete: coat directly on clean concrete cured at least 29 days, with moisture at 15% or less and sealers and release compounds removed. Wider cracks are reinforced with the polyester fabric KST20385A; Uniflex specifies its own sealant for the cracks, which we do not stock.
An existing coating: a sound, aged acrylic, silicone or urethane roof coating takes Silicone44 directly once it is washed, loose coating is scraped back and the adhesion tests pass.

Hypalon (CSPE) is the exception: no Uniflex silicone document covers it. A Hypalon roof that drains takes the single-ply acrylic system; for one that holds water, send us the roof. At curbs and penetrations Uniflex’s silicone specifications use its OneFlash sealant, which we do not stock either, so ask for it on the quote rather than reading one of our cartridges as the specified one.

Application

Start on a roof that is clean, dry and sound. Wet insulation is cut out and replaced, and ponded silt, loose granules and failed material come off first.
Run the adhesion test on every silicone job: a small patch with a fabric strip embedded, left three days, then pulled. Uniflex looks for at least 2 lb per inch; a lower result goes to Uniflex, which decides the primer. Test more often where the roof is worn, shaded, previously coated or holds water.
Close the details before any field work, with the materials the build-up above lists for that roof type.
Apply to the rates, the film build and the number of coats the data sheet states, in the conditions it allows, with no base coat under it.
Silicone44 resists ponding water, but it does not fix drainage. Uniflex’s silicone specifications still expect at least 1/4 in per ft of slope and working drains, and water that stands for long means more inspection, cleaning and recoating over the years.
Keep the product data sheet and the safety data sheet on site. They govern the work; this page is a description of what we stock.

Ordering

Order by KST044300-20 for the 5-gallon pail or KST044300-27 for the 55-gallon drum. Data sheets and the safety data sheet list this coating as 44-300; it is the same product. Stocked pack sizes ship in 1 to 3 business days; anything not on the shelf is ordered in and runs 1 to 2 weeks. Drums go by freight, with a lift-gate where there is no dock, and drums and pallet quantities go through the quote form; every price is quoted per project rather than printed here. Send the part numbers, the quantities, the site ZIP code and your dates, and we reply with the price, the freight and a ship date.

Where it's used

Metal panel roofs

Washed, fasteners tightened or replaced, laps open more than 1/8 in fastened, every rusted area primed with KST034520 and cured, and the end laps, fastened seams and ridge-cap laps striped with Silicone44 before the field coat.
EPDM

Repaired and washed, cleaned with the Bond-It wash primer KST038620, rinsed and dried, open seams and flashings sealed with the black MS hybrid KST058310, then coated. New, unweathered EPDM takes a different primer: ask us.
TPO and PVC

Weathered membrane repaired, washed and adhesion-tested, then coated directly: no primer, no base coat. A low test result or new membrane goes to Uniflex, which names the primer for that roof.
Smooth BUR, modified bitumen and cap sheet

Repaired and washed, with Uniflex's Bleed Blocker Primer first where the asphalt is newer or likely to bleed through (we do not stock it: ask on the quote). No MB base coat. Granulated cap sheets take more coating than smooth.
Sprayed foam and concrete

Foam with any wet or damaged foam cut out and replaced, and clean concrete cured at least 29 days at 15% moisture or less, sealers and release compounds removed. Silicone44 goes on directly, with no primer and no base coat.
Roofs already carrying a coating

A sound, aged acrylic, silicone or urethane roof coating, washed, with loose coating scraped back and adhesion tests passed, takes Silicone44 directly.

Specifications

Specifications: KST044300 Uniflex Silicone44 Rubberized Silicone Roof Coating, White
Manufacturer	Sherwin-Williams (Uniflex line)
Part number	KST044300 (product code 44-300)
Order numbers	KST044300-20, 5-gallon pail · KST044300-27, 55-gallon drum
Color	White
Pack sizes	5-gallon pail, 55-gallon drum
Base coat	None: the acrylic base coats belong to the acrylic systems

Performance
Technology	Silicone rubber
Recommended substrates	Metal, EPDM, TPO, PVC, smooth BUR, APP and SBS modified bitumen, granulated cap sheet, polyurethane foam, cured concrete, existing roof coatings
Elongation	315%
Tensile strength	250 psi
Tear resistance	25 lb per linear ft
Permeance	7.2 US perms
SRI	110

Ordering
SKU	CY-44-300
Sold by	Pail
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

Does Silicone44 need a base coat?: No. Uniflex's silicone specifications put Silicone44 KST044300 straight over the prepared roof with no acrylic base coat under it; the acrylic base coats belong to the acrylic systems. Some roofs need a primer: the rust-inhibitive primer KST034520 on rusted metal, the Bond-It wash primer KST038620 on EPDM, and Uniflex's Bleed Blocker Primer on asphalt that may bleed through, which we do not stock. Foam, cured concrete, weathered TPO and PVC and sound existing coatings take it directly.
How is the adhesion test done?: A small patch of Silicone44 with a strip of fabric embedded in it is left three days, then pulled. Uniflex looks for at least 2 lb per inch; a lower result goes to Uniflex, which decides the primer. Every silicone job gets one, and more of them where the roof is worn, shaded, previously coated or holds water.
Will it fix ponding water?: No coating fixes drainage. Silicone44 is the Uniflex coating made for areas where water stands, but Uniflex's silicone specifications still expect at least 1/4 in per ft of slope and working drains, and water that stands for long means more inspection, cleaning and recoating over the years. Uniflex's Slope Builder KST0SLPBD builds up low areas, but no silicone specification names it under Silicone44, so under silicone the adhesion test and Uniflex decide.
Can it go on a Hypalon roof?: No Uniflex silicone document covers Hypalon (CSPE). A Hypalon roof that drains takes the single-ply acrylic system: pressure wash, the single-ply base coat KST041321, then an acrylic finish coat. For a Hypalon roof that holds water, send us the roof: the primer under silicone has to come from Uniflex in writing, after an adhesion test.
Is Silicone44 a water-based coating?: No. It is a silicone rubber coating. The acrylic elastomerics elsewhere in the range are the water-based products; this one is not. The manufacturer's product data sheet states how it is handled, applied and cleaned up, and the safety data sheet covers storage and transport.
Do you apply the coating?: No. We stock the materials and ship them, and application is the contractor's work, done to the manufacturer's product data sheet. We can arrange a drone moisture scan of the roof before anything is coated, and we work with a network of installers, roofing contractors who apply these systems, and can introduce you to one anywhere in the US.
What about the system warranty?: Sherwin-Williams offers UNIGUARD system warranties of 10 or 15 years when one of its authorized contractors applies the system. The warranty is the manufacturer's, issued under its own terms; we supply the materials, and the goods are warranted to match their description.
Why does the data sheet say 44-300?: 44-300 is the manufacturer's product code and KST044300 is the same coating written as a part number; the order lines are KST044300-20 for the pail and KST044300-27 for the drum. The quote states the part number, the pack size and the quantity against the current data sheet, so a number read off an old spec never turns into a wrong pallet.