Exterior Painting Plan
Measure the house as one perimeter, add the gables, and check the weather window before you open a tin.
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The house
- Address
- Date
- Perimeter
- Wall height
- WALL AREA
- Gable width
- Gable rise
- Gables
- GABLE AREA
- Openings deducted
- NET AREA
- Coverage from the TIN
- Coats
- GALLONS
- Product
- Colour
Figures and rules
- Data-sheet coverage
- 350-400 sq ft/gal (SW SuperPaint Ext.)
- At
- 4 mils wet, 1.4 mils dry
- Stucco / rough cedar / block
- use 200-250 — it drinks paint
- Wall area
- perimeter x height to eaves
- Gable area
- base x rise / 2, per gable
- Gallons
- net area x coats / coverage
- ⚠ Minimum temperature
- 35F air, surface AND material
- ⚠ Dew point
- surface must be 5F above it
- Recoat above 45F
- 4 hours
- ⚠ Recoat at 35-45F
- 24-48 HOURS — plan for days
- Touch dry
- about 2 hours
- Buy pails past
- about 4 gallons
Elevation by elevation
| Elevation | Length | Height | Area | Openings | Net |
|---|---|---|---|---|---|
Before the first coat
- Overnight low checked, not just the afternoon
- Dew point checked — surface 5F above it
- Washed, and mildew killed rather than painted over
- Loose and flaking paint scraped back to sound
- Bare wood spot-primed — especially cedar and redwood knots
- Gaps caulked AFTER priming, not before
- Gables measured and included
- Enough paint for TWO coats bought in one go
- Multiple tins boxed together and mixed
- Windows, shrubs and paths covered
The gables are the part that gets forgotten
A gable is half the base times the rise. Two 30 ft gables with a 6 ft rise are 180 sq ft — a full gallon over two coats, and the hardest area on the house to reach. Measure them before the ladder goes up, not after.
The substrate costs you paint, not the brand
350-400 sq ft/gal is the data-sheet figure for a smooth, sound surface. Rough-sawn cedar, stucco, brick and split-face block have far more real surface than their flat measurement suggests. The same house at 200 instead of 350 needs seven more gallons — change the coverage input, not the brand.
Cold weather changes the schedule
Recoat is 4 hours above 45F but 24-48 hours at 35-45F. That is a two-coat weekend turning into a multi-day job. Below 35F, or within 5F of the dew point, it should not go on at all.