Stripping and Refinishing Hard Floors

A shiny hallway floor is not shiny by itself. It wears a coat of finish, and that finish takes the scratches so that the tile does not. Over time, it gets dull, scuffed, and yellow. Then it has to come off and go back on. Stripping is the heaviest floor job a cleaner does. It takes strong chemicals, slippery floors, and careful timing. One shortcut, usually in the rinsing, can ruin the whole job. Schools, hospitals, stores, and warehouses all do this work, often at night or between terms.

What You Will Be Able to Do

• Tell when a floor needs stripping and when it needs less
• Set up the area and protect yourself
• Apply stripper and remove old finish
• Rinse so the new finish will stick
• Apply thin, even coats of finish
• Spot floors that need special handling

Do You Need to Strip?

Stripping is costly and hard on the floor, so do the smallest job that will work.

Busy floors may need a strip a few times a year, and quiet floors much less often. A good maintenance plan makes stripping rare.

Check the Floor First

Vinyl composition tile (VCT) is the classic floor for this work. Others are different.

• Old tile may contain asbestos. Under OSHA's general industry rule, asphalt and vinyl flooring installed in 1980 or earlier must be treated as asbestos-containing unless it has been proven otherwise. Do not sand it. Strip finish only with low-abrasion pads, at under 300 RPM, using wet methods. Do not burnish it unless there is enough finish that the pad cannot reach the tile. Check your building's records before you start.
• Stone, terrazzo, and wood can be damaged by stripper. Ask first.
• Luxury vinyl and sealed floors may not be meant for stripping.
• New VCT often needs its factory coating removed, as the tile maker directs.

Read the stripper's label to confirm that it is safe for the floor.

Gear and Setup

Floor stripper is strongly alkaline, and it can burn skin and eyes. The most critical protection is chemical-resistant gloves, splash goggles, and non-slip boots. Check the Safety Data Sheet for anything more.

What you need:

• Low-speed floor machine or auto scrubber
• Black stripping pads, plus a brush or tool for edges
• Mop and buckets for stripper, and separate ones for rinsing
• Wet vacuum or auto scrubber for pickup
• Finish applicator, a clean bucket, and a liner
• Signs, cones, and barrier tape

Setting up:

1. Clear the room of furniture, or plan to do half at a time.
2. Block off the area. Put signs at each entry. A stripped floor is extremely slippery.
3. Dust mop thoroughly.
4. Protect baseboards with tape if needed, and keep stripper off walls.
5. Turn off HVAC or fans that would dry the floor too quickly, if you can. Have ventilation that clears the fumes.
6. Check that power cords are in good shape, and use outlets with GFCI protection.

Stripping

Work in sections small enough to finish before the stripper dries. A section of about 200 to 300 square feet is common when you are learning.

1. Mix the stripper to the label's dilution, using cool water unless the label says otherwise.
2. Apply it with a mop, flooding the section evenly. Keep it off the walls.
3. Let it sit for the label's dwell time, often 5 to 10 minutes. Do not let it dry. Add more if it starts to.
4. Scrub with a low-speed machine and a black pad. Edges and corners need a hand tool or an edge pad.
5. Pick up all the slurry with a wet vacuum or scrubber. Slurry is the dirty mix of old finish and stripper. It is the slipperiest thing you will ever walk on, so move slowly.
6. Check for leftover finish. Rub a spot with a white pad or your glove. If it looks dull and feels smooth with no film or shine, it is clean. Strip it again if you see shiny or gummy patches.

Dispose of slurry according to your site's rules. Stripper waste can contain metals from old finish. Do not pour it into a storm drain or onto the ground.

Rinsing

Rinsing is the critical step before any new finish goes down. Leftover stripper stops the finish from bonding, and the finish can powder, peel, or turn cloudy.

1. Rinse with clean, cool water, using a clean mop or a scrubber.
2. Pick up all the water.
3. Rinse a second time. Some sites use a neutralizer, as the label directs.
4. Let the floor dry completely. Run a clean white cloth over the floor. If it picks up powder, rinse again.

Keep everyone off the floor. Footprints and dust on a clean floor will end up under your finish.

Applying Finish

Use a clean, dedicated finish mop or applicator, and a clean bucket with a liner. Do not use a mop that has touched stripper or cleaner.

1. Start at the far side, and plan your way out.
2. Pour a line of finish, or dip your mop lightly.
3. Lay down a thin, even coat. Go around the edge of the section, then fill it in with figure-eight strokes.
4. Stop a few inches short of the baseboards on the middle coats, so that finish does not build up at the edges.
5. Let it dry until it does not feel tacky. This usually takes 30 to 45 minutes, and it takes longer in damp air.
6. Apply the next coat at a right angle to the last one.
7. Apply 3 to 5 coats in all, depending on traffic and the gloss you want.

Thin coats dry harder and clearer than thick ones. A thick coat stays soft, it can trap air, and it may scuff. Do not shake the finish. Shaking creates bubbles.

Let the last coat cure for at least 8 hours before foot traffic, and longer before you move furniture back. Read the label before you burnish or scrub, as many finishes need days to cure fully.

Worked example. A hallway is 8 feet wide and 100 feet long, which is 800 square feet. A finish label gives 2,000 square feet per gallon for each coat. Four coats cover 3,200 square feet in all, so you need about 1.6 gallons, or 2 gallons with a margin.

Scrub and Recoat

Scrub and recoat is the middle ground. It freshens a floor without a full strip.

1. Scrub with a neutral cleaner and a red or blue pad, removing the top layer only.
2. Rinse and let the floor dry.
3. Apply 1 or 2 thin coats of finish.

Common Problems

Common Mistakes

Check Your Understanding

1. A floor is dull but has no worn spots. Do you strip it?

No. Try burnishing, or a scrub and recoat. Strip only when the finish is failing.

2. You have scrubbed and picked up the slurry. What comes next before any finish goes down?

Rinse thoroughly to remove all stripper residue, then let the floor dry completely.

3. A new finish starts powdering a week after the job. What went wrong?

Stripper was probably left on the floor. The finish did not bond, so the floor needs to be stripped and rinsed again.

4. You are asked to strip a floor in a building from 1965. What do you check first?

Whether the tile contains asbestos. If it has not been proven asbestos-free, treat it as if it does, and use only low-abrasion pads, under 300 RPM, and wet methods.

Key Takeaways

• Do the smallest job that will work, from burnishing to scrub and recoat to stripping.
• Treat older vinyl and asphalt tile as asbestos unless proven otherwise.
• Wear chemical-resistant gloves, splash goggles, and non-slip boots.
• Never let stripper dry on the floor.
• Rinse thoroughly and let the floor dry completely before finishing.
• Lay down thin coats at right angles, and let them cure.