Which Topcoat Goes Over Your Epoxy Floor: T-521, T-520, T-444X, T-344, T-322, T-321, T-359 Compared

Put T-444X polyaspartic at 5 to 12 mils wet over a flake floor, T-521 water-based polyurethane over a solid-color or metallic floor in a house, T-520 matte in a basement, T-322 solvent urethane on a shop floor with forklifts, and T-359 where hot tires and dragged equipment are the load. Every epoxy base coat needs one of them: bare epoxy ambers in sunlight and scratches sooner than a urethane or polyaspartic film, and a full flake broadcast sheds without a clear coat locking it in.

Topcoat comparison matrix

	T-521	T-520	T-444X	T-344	T-322 / T-322S	T-321 / T-320	T-359
Chemistry	Water-based polyurethane	Water-based polyurethane	Polyaspartic	Polyaspartic, fast cure	Solvent polyurethane, VOC compliant	Solvent polyurethane	High-solids solvent urethane with aggregate, 3 parts
Finish	High gloss	Matte	High gloss	Gloss	Gloss / satin	Gloss / satin	Semi-gloss, textured
Solids	42% wt / 38% vol	60% wt / 55% vol	84% wt / 83% vol	85% wt / 81% vol	73% colors / 64% clear (wt)	60% / 56% (T-320: 65% / 58%)	93% wt / 92% vol
Mix	2:1	2:1	1:1	2:1	2:1	2:1	By weight, pre-measured
Applied at	3 to 5 mils wet	3 to 5 mils wet	5 to 12 mils wet; over 12 it bubbles	5 to 12 mils wet	3 to 5 mils wet	3 to 5 mils wet	Thin; a heavy coat traps solvent
Coverage	320 to 500 sq ft/gal; 1.5 gal per bay	320 to 500 sq ft/gal; 1.5 gal per bay	133 to 320 sq ft/gal; 2 gal per bay over flake	133 to 320 sq ft/gal; 1.5 gal per bay	320 to 500 sq ft/gal; 1.5 gal per bay	320 to 500 sq ft/gal; 1.5 gal per bay	About 600 sq ft per gal kit
Working time	60+ min; cover the pail	60+ min	10 to 20 min usable	5 to 10 min usable	120 to 240 min	120 to 300 min (T-320: 180 to 300)	1 to 2 hr
Recoat / foot traffic	8 to 12 hr / 24 hr	8 to 16 hr / 24 to 48 hr	6 to 9 hr / 24 hr	2 to 4 hr / 3 to 5 hr	5 to 9 hr / 14 to 24 hr	4 to 8 hr / 14 to 24 hr	6 to 10 hr / 14 to 24 hr
Full cure	3 to 5 days	3 to 5 days	2 to 7 days	24 to 48 hr	3 to 5 days	3 to 5 days	3 to 5 days
Apply at	60 to 90°F, 50 to 90% RH	60 to 90°F, 50 to 90% RH	50 to 90°F, under 85% RH	50 to 90°F, under 85% RH	45 to 90°F, under 90% RH	45 to 90°F, under 90% RH	50 to 90°F, 50 to 90% RH
UV stable	Yes	Yes	Yes	Yes	Yes, rated for exterior	Yes, weather resistant	Yes; clear has an amber tone, tint it over color
Wear and chemical notes	Scuff and UV protection, normal residential traffic	Same, and hides roller marks and scratches	Hardest-wearing clear in the line	Same chemistry as T-444X, faster	Hard, Shore D 62, Taber CS-17 22 mg; chemical and weather resistant; the Commercial Pro topcoat for forklift traffic. Tire contact may discolor the film, so vehicle bays get Light Gray or Medium Gray	Hardest film in the urethane line, Shore D 72; chemical resistant	Forklifts, hot tires, dragged equipment; high traction
VOC	306 g/L	Under 50 g/L	Under 95 g/L	Under 159 g/L	Under 335 g/L	Under 448 g/L	Under 95 g/L
Shipping	We call and swap a compliant topcoat in strict states	All states	All states	All states	Cannot ship to CA, DE, MD	Federal-VOC states only; the OTC and MRPO states order T-322, and CA, DE and MD get T-444X	All states
Odor, occupied space	Low odor; attached garages, basements, living space	Low odor; the basement topcoat	Ventilate	Ventilate	Solvent; ventilate; unsuited to unventilated occupied space	Same	Solvent; ventilate
Over flake or smooth	Smooth (solid color, metallic)	Smooth	Flake; also smooth	Flake over B-933 polyurea; also smooth	Smooth; pigmented or clear	Smooth; T-320 clear is unsuited to color coats per its data sheet	Smooth or light broadcast
Price per kit	1.5 gal $306.99; 3 gal $587.99	1.5 gal $437.99; 3 gal $843.99	2 gal $387.99; 10 gal $1,887.99	1.5 gal $249.99; 3 gal $493.99	Clear: T-322 1.5 gal $224.99, 3 gal $419.99; T-322S $214.99, $404.99. Pigmented kits cost more	Clear: T-321 1.5 gal $229.99, 3 gal $434.99; T-320 $214.99, $404.99. Pigmented kits cost more	1 gal $249.99; 4 gal $912.99

Prices and specs as of November 2026. Base coat recoat and cure data: recoat windows and cure times chart.

Which topcoat for which floor

1. Full flake garage floor: T-444X. It goes on at 5 to 12 mils wet, thick enough to fill around the chips, and it is the hardest-wearing clear in the line. It locks the chips in and leaves a surface that is easier to clean. One 2 gal kit per bay. It is the clear in the Garage Pro and Basement Full Flake kits. Add A-HWS anti-slip at the door and on ramps.
2. Solid-color or metallic floor in an attached garage: T-521. Low odor, 60+ min of working time, 3 to 5 mils wet from a roller tray, one 1.5 gal kit per bay. It is the topcoat in the Garage Pro System solid and metallic kits. In states with strict floor-coating VOC limits we call after you order and swap a compliant topcoat.
3. Basement, rec room, home gym, or any floor where gloss would show every roller mark: T-520. Same chemistry as T-521 in matte, under 50 g/L VOC. It is the topcoat in the Basement & Indoor Pro System. Tint either with an A-521P pigment pack, one quart per 1.5 gal kit, for a colored finish coat.
4. Shop, warehouse or auto service floor with forklifts: T-322 gloss or T-322S satin. Shore D 62, 2 to 3 mils dry per coat, cures to 45°F, 120 to 240 min of working time; a second coat goes on within 24 hr over a deglossed first coat, per its data sheet. The B-707 data sheet lists T-321 and T-322 aliphatic urethanes as the optional topcoats for increased chemical resistance or increased UV stability. It is the topcoat in the Commercial Pro System solid color kit. Its data sheet notes that tire contact may discolor the film, so in vehicle bays choose Light Gray or Medium Gray, or use T-359. Cannot ship to CA, DE or MD; those floors get a polyaspartic or water-based topcoat.
5. The same shop floor in a federal-VOC state where you want the hardest film: T-321 (Shore D 72) or T-320 satin. State list: VOC limits by state.
6. Dragged equipment, constant foot traffic, wet shop floors: T-359. Three parts with a fine aggregate for traction, 93% solids, about 600 sq ft per gal kit. The clear has an amber tone, so order a tint pack to match the base coat by phone.
7. Floor back in service tonight: T-344. Foot traffic in 3 to 5 hr, full cure in 24 to 48 hr. Usable working time is 5 to 10 min, which makes it an installer product; DIY floors use T-444X. Tint with A-PAP, one half pint per 1.5 gal kit.
8. Floor in sunlight: any of them. All are UV-stable, and bare B-707 ambers. See epoxy vs polyaspartic.

What goes over what

• Epoxy base coat (B-707, B-181, C-671): any topcoat here, applied inside the recoat window. B-707 recoats at 8 to 12 hr, when a thumbnail leaves no mark. Past 48 hr, sand or screen, vacuum twice and wipe first. Too early, the topcoat drags or stays tacky; too late without sanding, it peels in sheets (why epoxy floors peel and how to recoat).
• Polyurea base coat (B-933): T-444X or T-344 the same day, 3 to 6 hr after the base. A urethane also works per the product page; the One-Day kits use polyaspartic.
• Over an existing cured topcoat, years later: screen the whole floor to a uniform dull finish, vacuum, and apply the same family. Call us before putting epoxy over a cured polyaspartic or urethane; it needs a full screen and a test patch.
• Thickness: T-444X bubbles over 12 mils wet; T-359 traps solvent in a heavy coat. Roll T-521 from a tray at 3 to 5 mils wet.

Odor

T-521 and T-520 are the topcoats for an attached garage with bedrooms above it, a basement, or a retail space that stays open. The solvent urethanes T-322, T-321, T-320 and T-359 need ventilation during application and cure. T-444X and T-344 are lower VOC than the solvent urethanes and still need ventilation. See how long the epoxy floor smell takes to go away.

Common questions

What kind of sealer should I use on an epoxy garage floor?

A UV-stable clear topcoat. T-444X polyaspartic over flake, T-521 water-based polyurethane over solid color, T-322 or T-359 solvent urethane on a shop floor with forklifts.

Can you put a clear coat over epoxy?

Yes. Apply it inside the base coat's recoat window, 8 to 12 hr for B-707 and within 48 hr; after that, sand and vacuum first.

Is polyaspartic better than polyurethane as a topcoat?

T-444X is harder-wearing and goes on thicker, 5 to 12 mils wet, which suits flake. T-521 is low odor, goes on at 3 to 5 mils and gives 60+ min of working time, which suits a first-time installer on a smooth floor.

Which topcoat is best for a basement?

T-520 matte. Low odor, under 50 g/L VOC, UV-stable, hides roller marks. It ships in the Basement & Indoor Pro System.

The Garage Pro, Basement & Indoor Pro and Commercial Pro kits each include the right topcoat for their floor. To change it, or to match a topcoat to a floor that is already down, call (877) 703-7699, Monday to Saturday, 8am to 6pm ET.