Exterior projects
Planning a fence stain: sides, styles and weather
A 100 ft privacy fence, both sides, is over 1,200 sq ft of rough wood, three and a half times the walls of a 12 × 12 ft bedroom. Here is how to plan the stain, the days and the weather.
A fence is bigger than it looks
A fence is one long, thin rectangle, and it is easy to underestimate. A 6 ft fence 100 ft long is 600 sq ft on one face. Stain both faces and it is 1,200 sq ft, before adding gates, the extra surface of rough boards, or the edges of pickets. The wood is usually rough-sawn and often weathered, so coverage is far below the figure for paint on a smooth wall. And it is all outside, so the weather sets the schedule.
Measuring a fence
Measure along the fence line, and add about 4 ft for each gate, which has its own frame and boards. Count both sides if both will be stained; a neighbour’s side is their decision, and many people stain only their own. The style factor accounts for how much wood there is per square foot of fence face:
| Style | Factor | Why |
|---|---|---|
| Solid board, privacy | 1.0 | One continuous face of boards |
| Horizontal boards | 0.95 | Small gaps between boards |
| Shadowbox (board on board) | 1.3 | Overlapping boards on both sides of the rails, plus edges |
| Picket | 0.7 | Gaps between pickets, but more edges |
The factors are site estimates and are applied in the fence stain calculator.
Which product
| Product | Coverage on rough wood | Coats | Character |
|---|---|---|---|
| Clear or transparent sealer | 250 sq ft/gal | 1 | Protects, shows the wood, needs renewing soonest |
| Semi-transparent stain | 200 sq ft/gal | 1 | Colour with the grain showing; the most common choice |
| Solid-colour stain | 175 sq ft/gal | 2 | Opaque, hides old or mismatched boards |
| Exterior paint | 300 sq ft/gal | 2 | Opaque film; lasts but eventually peels |
These are typical figures from exterior stain data sheets for rough fence boards. Semi-transparent stain is the usual choice for wood fences: it soaks in, does not peel, and is recoated without stripping.
Worked fences
A 100 ft privacy fence, both sides
6 ft high, one gate, solid boards, semi-transparent stain, one coat, 5% allowance.
- Face: (100 + 4) × 6 = 624 sq ft
- Both sides: 1,248 sq ft
- Stain at 200 sq ft per gallon: 1,248 ÷ 200 × 1.05 = 6.55 gallons, buy a 5-gallon pail, a gallon and three quarts
The same fence with clear sealer takes 5.24 gallons, with solid-colour stain at two coats 14.98 gallons, and painted, at two coats, 8.74 gallons. One side only, with semi-transparent stain, 3.28 gallons. All from the fence stain calculator.
A picket fence
150 ft of 4 ft picket fence with two gates, both sides, semi-transparent stain, one coat.
- Face: (150 + 8) × 4 = 632 sq ft; both sides 1,264; picket factor 0.7: 885 sq ft
- Stain: 4.65 gallons, buy a 5-gallon pail
A shadowbox fence of the same 100 ft size as the first example takes 8.52 gallons, because of the overlapping boards.
Brush, roller or sprayer
A fence has a lot of area and a lot of edges, which suits a sprayer: a pump sprayer or an airless sprayer puts stain into the gaps and onto board edges quickly. The cost is overspray, which on a fence outdoors can be a third or more of the stain, and the risk of drifting stain onto cars, plants and the neighbour’s house. Spray on a still day, mask what matters, and back-brush the stain into the wood while it is wet, which gives a more even result than spraying alone. The airless sprayer usage calculator adds the overspray, and spraying versus rolling covers the trade-off.
A thick-nap roller or a stain pad works well on solid board fences; a brush is best for pickets and for working stain into rough wood.
Weather sets the schedule
Stain and paint both need a window of dry weather. Typical requirements, from stain data sheets, are:
- Air and surface temperature above about 50 °F during application and overnight.
- No rain for a day or so after application.
- Dry wood: a day or two of dry weather after cleaning or rain.
- Out of full, hot sun, which makes the stain flash and lap.
An oil-based penetrating stain is touch-dry in about 4 hours and ready for a second coat, if one is needed, after about 24 hours at 77 °F; in cooler or damper weather, longer. The drying and recoat calculator adjusts the times for your conditions, and dry, recoat and cure explains why cold slows everything.
How long it takes
A long fence is more work than people expect, because there is no large flat area for a roller to cover quickly. Plan in sections: one side of a run per session, starting at a gate or corner so that you can stop at a natural break. Do the gates and posts first, then the boards. For two sides, plan on two separate sessions with a dry day in between if the stain needs it.
Prep
Clean the fence with a deck and fence cleaner, scrub off mildew, rinse, and let it dry. Pressure washers work but can raise the grain and gouge soft wood if held too close; a low-pressure fan tip at a distance is safer. Replace rotten boards before staining, so the new wood gets the same treatment. Cover plants along the fence line and wet them down before you start.
New fences
A new wooden fence usually should not be stained the week it goes up. Pressure-treated lumber arrives wet with preservative and needs to dry out, often for weeks or longer, before it will absorb stain; cedar and redwood can usually be stained sooner. Use the water test from the deck stain guide: sprinkle water on a board, and when it soaks in rather than beading, the wood is ready. New, smooth boards also take less stain than weathered ones, so the first coat on a new fence may go further than the rough-wood figures above. Enter the coverage from the can if it gives one for new wood.
Keeping it up
How often a fence needs re-staining depends on the product, the sun and the climate more than on a calendar. Semi-transparent stain fades gradually and is renewed with a clean and a single coat, without stripping; that ease is its main advantage. Solid-colour stain and paint hold their colour longer but eventually crack and peel on the sunny side, and the peeling has to be scraped before recoating. Watch the south-facing side and the tops of boards: when water stops beading there, plan the next coat.
Metal and vinyl fences
Steel and wrought-iron fences are painted, not stained: wire-brush the rust, spot-prime bare metal with a rust-inhibiting primer, and finish with an exterior metal enamel. The metal railing and gate paint calculator handles their open structure. Vinyl fences are generally not painted; if they are, they need a paint made for vinyl in a colour light enough not to overheat in the sun.
Common mistakes
- Measuring one side and staining two. Both faces double the stain.
- Forgetting gates and posts. Add about 4 ft of fence per gate.
- Using smooth-wall coverage. Rough fence boards take far more.
- Spraying in wind. Overspray drifts onto cars and houses.
- Staining wet wood. The stain sits on the surface and wears off unevenly.
- Two coats of a penetrating stain that says one. The second coat stays tacky.
For decks, the same logic is set out in deck stain coverage and the deck stain calculator.