For exterior painting and coatings contractors
Start the coat at the hour it'll cure.
Every coat checked against dew, your product minimum and rain-safe hours, with odds from up to 146 forecast runs.
The costly call
A blushed finish coat is a repaint on your dime
A finish coat that blushes or streaks under evening dew, or gets rained on before it is rain-safe, is a repaint on your dime. A "20% chance of rain" says nothing about dew at 5 PM.
How it works
From your place to an answer
Add the job
Type the address of the house or building. Each job gets its own forecast.
Set your data sheet numbers
Set your product minimum, dew spread, rain-free hours and surface type from the data sheet.
Pick the start hour
See the best start hour for each coat, how sure that is, and when dew or rain would catch it.
In the app
See it on a real forecast
Real forecasts for Austin, Central Texas, captured October 5, 2026. Yours will be for your own place and limits.
What you get
Built for exterior painting and coatings contractors
Coat-and-cure odds by start hour
Every start hour today and tomorrow, with the odds the film stays warm, clear of dew and dry until it is rain-safe, and the hour dew or rain would catch it.
Recoat clock
When the last coat is ready for the next one, counted from when it went on: slower in cool hours, paused in cold or dew.
Surface temperature today
Which hours the wall is above your product floor and clear of dew, as an estimate for your siding, masonry or metal.
Stop-before-sunset coats
Prime, finish and recoat steps end a set time before sunset, so evening dew misses the wet film.
Elastomeric and masonry 24-hour rain check
Stucco, block or tilt-up: dry masonry before, warm enough after, and a full day without rain on the thick film.
Stain days that won't flash
Deck, fence, cedar and log stain on wood dry for two days, between 50 and 90 °F (a starting point: use the can) and clear of dew.
The steps it times
Pressure-wash & prep day
Wash, scrape and sand, leaving the siding a day to dry before primer.
6-hour window · daylight only
Prime / first coat
Spot-prime bare wood and repairs, or lay the first coat of a two-coat system.
4-hour window
Finish coat
The topcoat the homeowner sees, started early enough that dew does not hit it wet.
5-hour window
Stain coat (deck, fence, cedar or log)
Penetrating or semi-transparent stain on bare, dry wood that must not flash in full sun.
4-hour window · daylight only
Elastomeric or masonry coating
Stucco, block or tilt-up: a thick film that needs dry masonry and a full day without rain.
6-hour window
Caulk, glaze & carpentry repairs
Beads at trim, windows and joints, plus patch and glazing, inside the tube's temperature range.
4-hour window · daylight only
Recoat & touch-up
Second coat on one elevation, touch-ups and the punch list before the walk-through.
3-hour window
What else it watches
- Coat-and-cure odds by start hour
- Recoat clock
- Surface temperature today
- Rain on the job, last 3 days (is the siding dry?)
- Gusts for the spray rig
- Frost on the walls tonight
Every answer counts the forecast runs that keep the whole step inside your limits, at your job.
Founding members
Join the beta — your first six months free
Only 10 founding places: the first 10 exterior painting and coatings contractors to apply get the Exterior Painting & Coatings edition free for six months when it launches. No card needed. When they're gone, it's the waitlist.
Only 10 founding places.
- Your first six months of the Exterior Painting & Coatings edition free when it launches
- Early access to the app as it is today
- A say in which steps the Exterior Painting & Coatings edition times next
Questions
Asked before you start
How is this different from a weather app?
A weather app gives one forecast and a rain chance. This runs each coat, and the hours after it, through each of up to 146 forecast runs and tells you how many keep it clear of dew, cold and rain.
Can I keep a record of my calls?
Yes. Log a coat decision and the decision log keeps the odds, the forecast dew spread and temperature and your note for that job. Export it to CSV. It records what the forecast showed, not readings off the wall.
Does it know my wall temperature?
No forecast does. It estimates it from air, sun and wind for your surface type and labels it an estimate. It does not know which way a wall faces or what shades it.
What data does it use?
Forecasts for the job's grid cell: an hourly forecast plus up to 146 runs from three independent forecast systems, pooled and judged run by run, 14 days ahead. Only the runs that carry humidity judge dew, and each card says how many.
Whose limits are built in?
Sherwin-Williams data-sheet numbers as defaults; the rest say "starting point". Your product's data sheet always wins: set it in Setup. The Sherwin-Williams 35 °F, 5 °F above the dew point and 2–3 h rain-free figures are per research notes, unverified: we could not open the data sheets themselves.
What can't it tell me?
It has no moisture meter, so it cannot tell whether siding, deck boards or stucco are dry enough to coat. Dew on the film is inferred; there is no wetness sensor. There is no radar or lightning, so a pop-up shower over the job cannot be called an hour out.