# Deck stain calculator

> 16′ × 12′ deck: 502 sq ft to coat, 3 gal + 1 qt of stain in 2 coats, and 2 gallons of cleaner. Cleaner, brightener or stripper, stain or sealer by the gallon for your deck, railings, stairs and fence — first and second coats counted the way the cans say.

## What to buy (16′ × 12′ deck)

Every line shows the quantity to buy and how StudSheet got it: the spacing, the waste and the package size, so you can check it before the supply house or the quote.

| Buy | Material | How StudSheet counts it | What it is for |
|---|---|---|---|
| **3 gallons + 1 quart** | Exterior stain or sealer (deck and railing) (semi-transparent stain, 2 coats) | floor 211 sq ft + railings 259 sq ft + stairs 32 sq ft: 502 sq ft ÷ 250 sq ft/gal for the first coat + ÷ 500 sq ft/gal for the second (thin, wet-on-wet) = 3.01 gal. | Semi-transparent or solid exterior stain. Rough treated wood drinks more than the can’s coverage. |
| **2 gallons** | Deck and wood cleaner (concentrate) | 502 sq ft ÷ about 400 sq ft/gal mixed (labels: 250–500 sq ft/gal). | Lifts dirt, mildew and gray wood fibers before stain. Mixed with water as the jug says; a gallon cleans about 250–500 sq ft. |
| **2 gallons** | Wood brightener (oxalic acid) | 502 sq ft ÷ about 275 sq ft/gal: neutralizes the cleaner and brings gray wood back. | Oxalic-acid rinse that neutralizes a cleaner or stripper and brings back the wood’s color; about 250–300 sq ft a gallon. |
| **1** | Stain pad applicator with a refill | Lays stain along the boards without lap marks; fits the extension pole. | A flat pad on a pole that lays stain down board by board without lap marks. |
| **2 covers** | Roller covers 9″ (½″ nap) | Floors and fence boards, then back-brush; a spare. | Nap length depends on wall texture. |
| **2** | Plastic sheeting 9×12 | Over the plants, the siding at the deck’s edge and anything below that cleaner or stain can drip on. | Covers furniture. |

### In Canada (4.88 m × 3.66 m deck)

Set to Canada, the Sheet works the job out again for Ontario: metric sizes, bag sizes, the frost depth and the code notes. It doesn't just convert feet to meters. The first lines:

- **3 × 3.78 L + 1 × 946 mL, Exterior stain or sealer (deck and railing):** floor 19.6 m² + railings 24.1 m² + stairs 3.0 m²: 46.7 m² ÷ 23.2 m² per 3.78 L for the first coat + ÷ 46.5 m² per 3.78 L for the second (thin, wet-on-wet) = 11.4 L. Cans are counted at 3.78 L — read the litres on the can (Canadian “gallon” cans hold 3.6–3.79 L).
- **2 jugs (3.78 L), Deck and wood cleaner (concentrate):** 46.7 m² ÷ about 37.2 m² per 3.78 L mixed (labels: 23.2–46.5 m² per 3.78 L).
- **2 jugs (3.78 L), Wood brightener:** 46.7 m² ÷ about 25.5 m² per 3.78 L: neutralizes the cleaner and brings gray wood back.
- **1, Stain pad applicator with a refill:** Lays stain along the boards without lap marks; fits the extension pole.
- **2 covers, Roller covers 230 mm:** Floors and fence boards, then back-brush; a spare.
- **2, Plastic sheeting 2.7 × 3.7 m:** Over the plants, the siding at the deck’s edge and anything below that cleaner or stain can drip on.

## The steps, in order

> **DIY OK: you can do this yourself with standard tools.** About 23–36 hours of work for this example.

1. Check the wood: replace soft boards and set popped nails (the Deck Sheet covers structure).
2. Clean: wet the plants and siding, spray the cleaner on, scrub it in, and rinse — low pressure, a fan tip, with the grain.
3. Brighten: spray the brightener on while the wood is wet, let it work, and rinse.
4. Dry: let the wood dry 24–48 hours with no rain — stain needs dry wood.
5. Sand the fuzz the washer raised, lightly, and sweep and blow the deck clean.
6. Stain: railings and balusters first; then the floor two or three boards at a time, end to end, keeping a wet edge; the stairs last, working off the deck; back-brush so it soaks in, and wipe off any puddles.
7. Recoat: the second thin coat goes on wet-on-wet, within the can’s window (Behr: about an hour or two), before the first one dries.
8. Keep foot traffic off for 24–48 hours and furniture off for 72; lay used rags flat outside to dry.

## Tools (12)

Must-have tools first, then the ones that help and the ones to rent for the day.

| Tool | Need | Why |
|---|---|---|
| **Pump sprayer** | **Must have** | Puts the cleaner and brightener on evenly |
| **Stiff deck brush on a pole** | **Must have** | Scrubs the cleaner into the boards |
| **Pressure washer** | Good to have | Or a garden hose: low pressure, a fan tip, with the grain |
| **9″ roller frame** | **Must have** | Holds the roller cover. |
| **Extension pole** | **Must have** | Floors standing up; the pad fits it too |
| **2″ angled trim brush** | **Must have** | Balusters, rail edges and back-brushing |
| **Paint tray** | **Must have** | Roller reservoir. Liners make cleanup a toss. |
| **Pole sander** | Good to have | Sands the fuzz off the floor |
| **Random orbit sander** | Good to have | Rails and rough spots |
| **Work gloves** | **Must have** | Cleaners, brighteners and strippers are caustic |
| **Safety glasses** | **Must have** | Splashes and spray |
| **Organic-vapor respirator** | Good to have | Oil-based stain and strippers in still air |

## Mistakes and how the math works

### Mistakes that cost a callback or a second trip

- **Staining wet or new wood that beads water:** The stain can’t soak in and peels. Sprinkle water on a board: when it soaks in within minutes, stain.
- **One heavy coat:** It stays sticky and peels. Thin coats, back-brushed, and wipe up puddles.
- **Semi-transparent over solid stain or paint:** It can’t get into the wood. Strip to bare wood, or stay with a solid stain.
- **Lap marks:** Stopping mid-board leaves dark stripes. Finish whole boards end to end, keeping a wet edge.
- **Staining in hot sun:** It flashes off before it soaks in. Work the shady side, early or late.
- **Balled-up oily rags:** Oil-based stain on a wadded rag can catch fire by itself. Lay them flat outside or soak them in water.

### What the calculator assumes

- Areas: deck floor 16′ × 12′ + 10% for board edges and gaps; 37 ft of railing × about 7 sq ft a foot of rail (both faces); 4 steps × about 8 sq ft (tread, riser, stringer faces).
- Coverage per gallon on smooth wood: semi-transparent stain 250 sq ft/gal first coat, 500 sq ft/gal second (Behr semi-transparent: 250–300 then 500–600 sq ft a gallon; Olympic one-coat: 250–350; rough wood at the low end).
- Cleaner about 400 sq ft, brightener 275 sq ft, stripper 125 sq ft a gallon (the middle of the labels’ ranges).
- Cans: up to a quarter gallon over is a quart; four gallons or more of the rest become a five-gallon pail.

## Code, permits and safety

The Sheet sets its code notes for the job's state or province. These are New Jersey's and Ontario's; the [code reference](https://studsheet.com/codes) has more. Always confirm with your building department.

- **Stain weather:** Most stains go on between about 40°F and 90°F with no rain for a day (Behr’s semi-transparent stain); Olympic’s one-coat stain wants 35°F or warmer for 24 hours. Dry wood, no direct midday sun, no dew coming — read the can.
- **Oily rags:** Rags soaked in oil-based stain can heat up and catch fire on their own: lay them flat outside to dry, or soak them in a closed can of water.

## Questions

### What materials do I need to stain or seal a deck or fence?

For the worked example, a 16′ × 12′ deck, the Sheet counts 6 lines with waste included, starting with exterior stain or sealer (deck and railing) (3 gallons + 1 quart), deck and wood cleaner (concentrate) (2 gallons), wood brightener (2 gallons), stain pad applicator with a refill (1). Each line's math is in the table above. Put in your own sizes in the [deck & fence stain calculator](https://app.studsheet.com/p/stain) and every line is counted again.

### How long does it take to stain or seal a deck or fence, and can I do it myself?

About 23 to 36 hours for the worked example, in 8 steps. StudSheet stamps it **DIY OK**: you can do this.

### What tools do I need to stain or seal a deck or fence?

12 in all. The must-haves start with pump sprayer, stiff deck brush on a pole, 9″ roller frame, extension pole, 2″ angled trim brush, paint tray. On the Sheet you mark each one as owned, to buy or to rent.

## Ask about it

Stuck while you stain or seal a deck or fence? Ask in the [Deck and fence stain group](https://studsheet.com/forum/deck-stain) of the StudSheet community with this Sheet attached. Homeowners who've done it and verified pros answer, and anyone can read it.

## More painting Sheets

- **[Painting for contractors](https://studsheet.com/trades/painting)**: run this takeoff at your own prices, send the estimate, and get it signed and the deposit paid.
- **[Paint a room](https://studsheet.com/sheets/paint)** (14′ × 12′ room): Prep, primer, paint and supplies — walls, ceiling, trim and doors.
- **[Paint the outside of a house](https://studsheet.com/sheets/extpaint)** (40′ × 25′ house, 2 stories): Siding, trim, doors and shutters: gallons, primer, caulk and ladders, with lead-safe rules for older homes.
- **[Paint kitchen cabinets](https://studsheet.com/sheets/cabinets)** (20 doors, 8 drawers): Doors, drawer fronts and boxes counted into square feet: degreaser, sanding, bonding primer, cabinet enamel, rollers or a sprayer, and the days it takes.
- **[All 45 Sheets](https://studsheet.com/sheets)**, across 16 trades.
- **[Code reference](https://studsheet.com/codes):** frost depths, guard heights, stairs, retaining walls.