Exterior paint by siding type (wood, stucco, brick, vinyl)
Two houses with the same square footage of siding can need wildly different amounts of paint and prep — because the siding is different. Before you price an exterior job, identify the surface, because it decides your coverage, your primer and half your budget.
The siding, not the square footage, sets the buy
Exterior estimates go wrong when people price off area alone. The surface controls how far a gallon goes, whether you need a special primer or coating, and how much prep the job carries. Smooth vinyl and rough stucco with identical square footage are not the same job — not even close. So the first step is to name the siding, then pull its coverage from the coverage-by-surface reference.
Wood siding and trim
Wood is the classic repaint surface — and a demanding one. It expands and contracts, it can bleed tannin, and bare or weathered wood is porous, so coverage runs lower (200–300 sq ft/gal on rough or bare wood) and a sealing primer is usually needed to stop bleed and lock down the surface. Prep is real: scrape failing paint, sand, spot-prime, caulk gaps. Use a quality exterior acrylic over a proper primer.
Stucco and rough masonry
Stucco is thirsty and textured, so it drinks paint — plan on 150–250 sq ft/gal, well below smooth siding, and often a masonry primer or a thicker masonry/elastomeric coating that bridges hairline cracks. The rough texture also has far more real surface than its flat footprint, compounding the paint use. This is the surface most likely to double your gallon count versus a smooth-siding assumption.
Brick
Unpainted brick has the lowest coverage of common surfaces — 100–200 sq ft/gal — because it is porous and irregular, and it needs a masonry primer/sealer and a masonry or elastomeric paint. It is also close to a one-way decision: painted brick is hard to return to bare and needs maintenance thereafter. Weigh that before committing. The brick, stucco & concrete reference carries the masonry planning values and the moisture caution.
Vinyl and smooth lap siding
Smooth vinyl and lap siding are the friendliest: 300–400 sq ft/gal, minimal texture, often little more than a wash and a coat or two of a quality exterior acrylic — provided you use a paint rated for vinyl and a color within vinyl’s heat-safe range (too dark a color can absorb heat and warp the siding). Least paint, least prep, lowest cost per square foot of the four.
Fiber cement, aluminum and the rest
Two more surfaces are common enough to plan for. Fiber-cement siding (a popular modern lap) paints much like smooth wood — good coverage near 300–400 sq ft/gal and a quality exterior acrylic — but factory-primed boards want a light scuff and any cut ends sealed. Aluminum siding that has gone chalky needs a thorough wash to remove the powder and often a bonding primer, or the topcoat lifts. Weathered, chalky anything is the trap: the loose powder is a release layer, so test by rubbing a dark cloth on the siding — if it comes away colored, you have chalk to wash and prime before a drop of finish goes on.
Worked example: same area, different gallons
Take 2,358 sq ft of net exterior wall, two coats. On smooth siding at 350 sq ft/gal: ceil(2,358 × 2 ÷ 350) = 14 gallons. On rough stucco at 200: ceil(2,358 × 2 ÷ 200) = 24 gallons. On unpainted brick at 150: ceil(2,358 × 2 ÷ 150) = 32 gallons. Identical wall, more than double the paint — and the prep and primer climb the same way. The exterior siding paint calculator lets you plug in the surface’s coverage, and the cost by siding type tool carries the per-siding cost band.
Time the exterior job to the weather
Outside, the calendar is part of the spec. Exterior paint has a temperature and moisture window — too cold and it will not coalesce, too hot or in direct blazing sun and it flashes off before it levels, too damp and it will not adhere — so a meticulous planner reads the forecast before opening a can. Aim for mild, dry days, follow the sun around the house so you are not painting the wall it is baking, and leave dry time before any evening dew or rain, which can wash a fresh coat right off. Bare wood and washed, chalky surfaces must be fully dry before primer. Because an exterior repaint is measured in days, not hours, sequence it by elevation and shade and build the weather margin into the schedule — a rained-on coat is a redone coat, and that is real paint and real labor down the drain.
Paint the surface — do not confuse it with replacing it
This is a painting plan for the siding you already have. Replacing siding, roofing, gutters or cladding is a different trade with its own estimators — here you are refinishing the existing wood, stucco, brick or vinyl, not installing new. And on anything built before 1978, disturbing old exterior paint falls under the EPA RRP rule: use a certified firm.