Manuall Trade Library Run your shop on Manuall

Sherwin-Williams Emerald Rain Refresh Application Spec

How-to Guide Operations Updated Jul 24, 2026 ยท Painting

Why this matters

Sherwin-Williams Emerald Rain Refresh is a self-cleaning exterior acrylic latex with a hydrophobic surface technology that uses rain to mobilize and rinse surface contaminants (dust, pollen, dirt, mildew spores) off the painted facade. It is marketed at the top of the SW exterior catalog and carries a price premium over Resilience and SuperPaint. The performance the customer paid for only shows up when the prep, primer, mil thickness, and application conditions match the SW Product Data Sheet (PDS). A crew that applies it like SuperPaint loses the hydrophobic surface and the self-cleaning effect within one season, and the customer reads online and calls back. This document is the field spec your crew runs when Rain Refresh is on the bid.

What Rain Refresh actually is

  • Topcoat: 100 percent acrylic latex with a proprietary hydrophobic surface technology
  • Sheen options: Flat, Satin, Semi-Gloss (verify current SW PDS for color and sheen availability)
  • VOC: under 50 g/L (current PDS, verify), compliant with SCAQMD Rule 1113 and CARB SCM for non-flat exterior architectural coating
  • Coverage: 350 to 400 sq ft per gallon at recommended wet mil
  • Recommended dry film thickness: 1.4 to 1.6 mils per coat, two coats spec
  • Substrate range: properly prepared exterior wood, vinyl, aluminum, masonry, fiber cement, stucco

The hydrophobic surface comes from how the topcoat film cures, not from a topical wax or sealer. Anything you do on top of cured Rain Refresh (overcoat, sealer, second product) destroys the self-cleaning function.

Substrate prep that protects the warranty

Sherwin-Williams Emerald-line warranties (Lifetime Limited on the product, per current SW residential warranty) require documented prep and primer per the PDS. The crew that skips primer to save 2 hours costs the company a warranty claim later.

Wood siding:

  • Pressure wash at 1500 to 2500 PSI, 25-degree tip, 12 in to 24 in standoff; lower the PSI on cedar and redwood to avoid raising the grain
  • Allow 72 hours of dry weather before topcoat (moisture meter reading under 15 percent at substrate)
  • Hand-sand glossy spots and previous coating edges to 120 grit
  • Spot-prime bare wood with SW Exterior Latex Wood Primer or SW Multi-Purpose Latex Primer
  • Caulk gaps with SW Powerhouse Acrylic Latex caulk or equivalent ASTM C920 Class 25

Stucco and masonry:

  • Power wash and allow 72 hours of dry weather
  • pH must be at or below 10 (test with a Hach pH-paper kit); fresh stucco often reads 12+
  • Apply SW Loxon Conditioner to seal porous masonry; SW Loxon XP self-priming alkali-resistant masonry coating is another option for high-pH or fresh substrates

Vinyl siding:

  • Wash with TSP-PF or Krud Kutter Original Concentrated Cleaner
  • Test color compatibility per SW Vinyl Safe Colors program; not every color is safe on vinyl (heat-induced warping)
  • No primer required on properly washed vinyl

Aluminum:

  • Wash, hand-scuff with a Scotch-Brite pad
  • Spot-prime any oxidized areas with SW Pro-Cryl Universal Primer

Application conditions

Rain Refresh PDS requires:

  • Air temp 35 F to 100 F during application and through cure
  • Substrate temp at least 5 F above dew point; check substrate with an infrared thermometer (Fluke 62 MAX or Klein IR1)
  • Humidity below 85 percent
  • No rain forecast for 24 hours after application
  • No application in direct sun on a hot wall (skinning the surface before underfilm cures defeats the hydrophobic surface)

Plan the day around the wall orientation. South-facing walls early morning; west-facing late afternoon; never the south wall at 2 pm in July.

Application method

Spray plus back-brush is the SW-recommended method for Emerald-line exterior over wood and masonry. Spray alone leaves an uneven film on textured siding and shorts the hydrophobic surface in low spots.

Sprayer setup:

  • Graco airless (Magnum X7, GMAX 3900, or larger) or Titan equivalent
  • Tip: 515 to 517 for wood siding, 519 for stucco and rough texture
  • Pressure: 2000 to 2500 PSI; adjust down to eliminate tails and fan-edge spray
  • Filter: 60-mesh inlet, 100-mesh gun screen
  • Hose: 50 ft 1/4 in followed by 6 ft 3/16 in whip for control

Brush and roller backup:

  • 3 in or 4 in Purdy XL Glide or Wooster Pro/Doo-Z for back-brush
  • 9 in 1/2 in nap microfiber roller for back-roll on stucco

Wet-on-wet, back-brush within 60 seconds of spraying; back-brushing after the surface skins lifts wet paint into the brush and leaves brush marks.

Coat count and recoat window

Two coats required for the SW warranty:

  • First coat: 350 to 400 sq ft per gallon, 1.4 to 1.6 mils dry
  • Recoat window per PDS: 4 hours minimum at 77 F, 50 percent RH; longer at lower temp or higher humidity
  • Second coat same spec
  • Full cure to expected hydrophobic surface: 14 to 28 days depending on temp and humidity

The self-cleaning behavior develops as the topcoat continues to cross-link. The first heavy rain at 7 days will not produce the same beading as the first rain at 28 days. Set customer expectations in the close-out.

Color selection that supports the value proposition

Rain Refresh is most effective at hiding atmospheric dust on mid-tone and light colors. Deep accents (deep red, near-black, navy) still benefit from the hydrophobic surface but show drying spots more visibly. Set customer expectations:

  • Light to medium grays, taupes, whites: Rain Refresh hides dirt almost invisibly
  • Dark colors: the self-clean still works but visible water spotting may occur until the next rain washes the wall
  • Vinyl Safe Colors restricted on vinyl substrates; Rain Refresh follows the SW Vinyl Safe Color database

Documentation for the customer file

Per job, log:

  • SW product code, batch number from the can label
  • Color name and code, sheen
  • Total gallons used per coat
  • Square footage covered
  • Substrate type and prep performed
  • Temperature, humidity, and dew point at application
  • Photos of prep, primer, and final coats

Sherwin-Williams warranty claims require this documentation. The Manuall service ticket should template these fields for Emerald-line jobs.

What kills the self-cleaning

Common ways the field defeats the product:

  • Skipping the back-brush, leaving an uneven mil thickness
  • Applying below recommended mil thickness to "stretch" the gallon
  • Topcoating with an unrelated sealer or anti-graffiti coat
  • Pressure-washing the cured film at high PSI; the customer asks for a "freshen up" wash a year later and the wash strips the hydrophobic surface
  • Letting the customer hire a soft-wash crew that uses a strong cleaner; verify the cleaner's compatibility with Emerald-line coatings before any wash

Brief the customer on aftercare at close-out: hose-rinse only for the first season, never pressure-wash, mild dish-soap-and-water if a stain needs touch-up.

References

  • Sherwin-Williams Emerald Rain Refresh Product Data Sheet (PDS), current revision
  • Sherwin-Williams Architectural Coating Warranty terms, current
  • SCAQMD Rule 1113, Architectural Coatings (most recent amendment)
  • CARB Suggested Control Measure (SCM) for Architectural Coatings, current
  • ASTM D6386, Standard Practice for Preparation of Zinc (Hot-Dip Galvanized) Coated Iron and Steel Product and Hardware Surfaces for Painting
  • Master Painters Institute (MPI) Architectural Painting Specification Manual, current

Related articles