In part one of this series, we covered the daily sweeping and vacuuming routine that keeps most dirt and grit from ever becoming a problem. This part goes further into what to do once something's already gone wrong: stubborn dirt that a damp mop won't shift, and specific stains that each need a slightly different approach to lift cleanly without damaging the finish underneath.
Choosing the right cleaning product
Not every stain responds to plain water, and reaching for whatever's under the kitchen sink is the single most common way people accidentally damage a prefinished floor's finish. A water-based cleaner with a neutral pH is the safest general-purpose option for polyurethane surfaces, since it lifts dirt without reacting with the finish the way acidic or alkaline products can.
A few points worth keeping in mind when picking a product:
- Test any new cleaner in an inconspicuous spot first, such as inside a cupboard or under a piece of furniture, before using it across the whole floor. This catches any discolouration or dulling before it happens somewhere visible.
- Skip the all-purpose supermarket spray. General household cleaners are often formulated for tile, laminate or countertops, not polyurethane-finished wood, and can leave a residue or dull the sheen over repeated use.
- A mild, well-diluted dish soap can work in a pinch, despite sometimes being listed as something to avoid. The issue isn't soap itself, it's using it undiluted or leaving a film behind by skipping the rinse and dry step afterward. A dedicated wood floor cleaner remains the safer default, but a properly diluted mild soap isn't the enemy some cleaning guides make it out to be.
- Ammonia-based products should be avoided entirely, since they're genuinely harsh enough to strip and dull a polyurethane finish rather than just risk it.
- Always read the manufacturer's instructions for both the floor's finish and the cleaning product itself, since dilution ratios and contact times vary between brands.
A stain-by-stain guide
Different stains respond to different treatments, and using the wrong method can sometimes push a mark deeper into the finish instead of lifting it. Here's how to approach the most common ones:
| Stain type | How to treat it |
|---|---|
| Water rings or dark water marks | Rub gently with a small amount of mineral oil on a soft cloth, following the grain. For a stubborn ring, a thick paste of baking soda and water left to sit for a few hours before wiping away often finishes the job. |
| Grease or oil-based spills | Blot up any excess immediately, then sprinkle baking soda or cornstarch over the mark and leave it to absorb the oil for several hours before vacuuming it away. |
| Wine, juice or coffee | Blot straight away with a dry cloth rather than rubbing. If a mark remains once dry, a cloth dampened with a little water and a drop of mild dish soap, wiped gently along the grain, usually clears it. |
| Ink | Dab, don't rub, with a cotton swab lightly dampened with rubbing alcohol. Rubbing spreads ink further into the finish, so patience and light dabbing matter more than pressure here. |
| Wax, crayon or chewing gum | Harden the deposit first with an ice pack or a bag of ice, then gently scrape it away with a plastic scraper or an old credit card, working carefully to avoid scratching the finish underneath. |
For any stain that doesn't lift with these methods, it's worth stopping rather than reaching for something stronger like bleach or undiluted vinegar, both of which risk permanently damaging a polyurethane finish even though they're common suggestions in general household cleaning advice.
When a stain isn't a cleaning problem anymore
Some marks have simply gone past what cleaning can fix. If a stain has soaked through the finish into the bare wood underneath, rather than sitting on the surface, no amount of the right product will fully lift it, and it needs sanding and spot refinishing instead. Our guide to the main parquet flooring issues covers how to tell surface marks apart from deeper damage, and what's realistic to handle yourself versus what's worth having a professional look at.
If you're dealing with a stain that's beyond what these methods can manage, or you'd simply rather have your floor's regular maintenance handled properly, our parquet floor fitting team can advise on spot repairs and refinishing across London. Get in touch for a free quote if that's the direction you need.
Frequently asked questions
Can I use baking soda directly on a polyurethane finish without scratching it? Yes, baking soda is fine and non-abrasive enough for a factory finish when used as a paste with water, rather than sprinkled dry and scrubbed in. It works by gently lifting the stain rather than physically abrading the surface.
Is it ever safe to use vinegar on a prefinished floor? It's best avoided altogether for both routine cleaning and stain removal, since even diluted vinegar's acidity can etch a polyurethane finish with repeated contact. The methods in this guide avoid it deliberately for that reason.
How do I know if a stain needs sanding rather than cleaning? If the mark has a texture change, feels rough, or looks like it's gone through the finish into the wood grain itself rather than sitting on the surface, cleaning products won't fully remove it. That's the point to stop and consider a spot sand and refinish instead.
