Exterior paint for 260 ft of T1-11 siding at 20 ft high, 2 coats
| Paint | 47.37gal |
|---|---|
| What to buybuckets pay from about 3.6 gal up | 10 × 5 gal |
| PrimerT1-11 plywood siding is porous — primer is a separate coat, not an option | 29.81gal |
| Wall area260 ft perimeter × 20 ft, less 6 windows and 2 doors | 5,068ft² |
| Spread raterough face plus deep grooves — thirsty | 200ft²/gal |
| First coat | 25.34gal |
| Each later coat15% further on a sealed surface | 22.03gal |
| Doubling the first coat would say3.31 gal more than needed | 50.68gal |
- Perimeter
- 260 ft
- Wall height
- 20 ft
- Siding
- T1-11 siding
- Coats
- 2
- Windows
- 6
Texture decides the spread rate, not the brand
T1-11 siding takes about 200 ft² per gallon. The same house in smooth fiber cement would take noticeably less, and in brick noticeably more — the mortar joints drink more than the brick does.
260 ft of perimeter at 20 ft high, less 6 windows and two doors, is 5,068 ft². At 2 coats that is 47.37 gallons.
The second coat is cheaper
Once the surface is sealed, paint spreads about 15% further. Doubling the first coat would say 50.68 gal — 3.31 gal more than you need, sitting in the garage until it separates.
Two weather limits matter more than the gallon count
Surface temperature has to stay above about 10 °C for the whole cure, not just while you are painting. A warm afternoon followed by a cold night gives a film that never properly coalesces, and it comes off in sheets the following spring.
Dew point matters as much as rain. Early-morning painting on a clear autumn day fails constantly for exactly this reason — the siding is wet with dew that you cannot see.
Wash first, and wait
Paint over chalky or dirty siding fails at the interface however good the paint is. Pressure-washed wood needs two or three dry days; a moisture meter reading under 15% is the honest test, not "it looks dry".
Back-roll anything you spray
Spray lays paint on the surface. Back-rolling works it into the grain and the grooves. On T1-11 siding that is the difference between six years and twelve.
Notes
- **Surface texture, not brand, decides the spread rate.** T1-11 plywood siding takes about 200 ft² per gallon — rough face plus deep grooves — thirsty. The same house in smooth fibre cement would take 14.48 gal per coat against 25.34 here.
- **Two weather limits matter more than the gallon count.** Surface temperature must stay above about 10 °C for the whole cure, not just while you are painting — a warm afternoon followed by a cold night gives a film that never coalesces. And the surface has to be dry: dew point matters as much as rain, which is why early-morning painting on a clear autumn day so often fails.
- T1-11 plywood siding needs primer as a separate coat — 29.81 gal. On brick and stucco a masonry primer also seals the alkalinity that otherwise burns through the topcoat as patchy discolouration months later.
- Wash it first, and let it dry properly. Paint over chalky or dirty siding fails at the interface no matter how good the paint is, and pressure-washed wood needs two or three dry days before it is ready — a moisture meter reading under 15% is the honest test.
- Back-roll anything sprayed. Spray alone lays the paint on the surface; back-rolling works it into the grain and the grooves, and on T1-11 plywood siding that is the difference between six years and twelve.
- Buy it all at once and box it. Exterior walls are seen in full sun from a distance, which is the least forgiving lighting there is for a batch difference.
Nearby sizes
- Exterior paint for 250 ft of T1-11 siding at 20 ft high, 2 coats
- Exterior paint for 270 ft of T1-11 siding at 20 ft high, 2 coats
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- Exterior paint for 260 ft of T1-11 siding at 18 ft high, 2 coats
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- Exterior paint for 260 ft of shiplap siding at 20 ft high, 2 coats
- Exterior paint for 260 ft of stucco at 20 ft high, 2 coats
- Exterior paint for 260 ft of lap siding at 20 ft high, 2 coats
- Exterior paint for 260 ft of bare brick at 20 ft high, 2 coats
- Exterior paint for 260 ft of T1-11 siding at 20 ft high, 1 coats
- Exterior paint for 260 ft of T1-11 siding at 20 ft high, 3 coats
- Exterior paint for 260 ft of T1-11 siding at 20 ft high, 2 coats
- Exterior paint for 260 ft of T1-11 siding at 20 ft high, 2 coats
Read more
- How Much Exterior Paint — Texture Decides It, Not BrandThe gap between smooth fibre cement and bare brick is nearly three to one. The gap between the cheapest and dearest paint is nothing like that.
- Paint Coverage per Gallon by Surface — the Full Table, and Why the Label Is OptimisticEvery label says 400 square feet. Almost no real surface delivers it, and the ones that miss badly miss by half.
- Cost to Paint a Room — Where the Money Goes, and Why Trim Costs More Than WallsPaint is about a tenth of the bill. Prep and trim are most of it, and trim does not scale with room size at all.
- How Much Paint for a Room — Spread Rate Belongs to the Surface, Not the TinChoosing paint by the coverage claim on the label compares products on a number that describes a wall you do not have.