Each entry is quoted from its source and linked to it. The full set is in the standards reference.
Preventing scratches: glides, shoes, claws, grit
The US National Wood Flooring Association advises fabric-faced glides under furniture legs to prevent scuffing and scratching, avoiding cleats, sports shoes and high heels, keeping pet claws trimmed, and notes that particles can be ground into a floor and damage its finish.
“Put fabric-faced glides under the legs of furniture to prevent scuffing and scratching. … Avoid walking on wood floors with cleats, sports shoes, and high heels. 3. Keep pet claws trimmed and in good repair. … Particles have the potential to be ground into floors potentially causing damage to a floor’s finish.”
Source: NWFA Wood Flooring Installation Guidelines, Revised 2025 - National Wood Flooring Association, maintenance chapter, general protectionMost scratches are in the finish
The US National Wood Flooring Association says most scratches in a wood floor are in the finish, not the wood, and that a professional may be able to lightly abrade the finish and apply a new coat; it also recommends breathable rugs at all doors to keep grit out.
“placing breathable rugs at all doors will minimize dirt and debris from being tracked inside and help protect your floor from scratches. … Most scratches in wood flooring will occur in the finish, not the wood itself. A professional may be able to lightly abrade the finish and apply a new coat to restore the floor.”
Source: Homeowner's Handbook to Real Wood Floors - National Wood Flooring Association (PDF, 2019)Deep scratches: when a full sand and refinish is due
The US National Wood Flooring Association recommends a complete sand and refinish when a wood floor has damage such as deep scratches or dents, or when the finish has worn away.
“A complete sand and refinish is recommended when there is damage to the wood floor like deep scratches, dents, and other flooring damage. It is also recommended when the finish has worn away,”
Source: Refinishing Your Floors - woodfloors.org, consumer site of the National Wood Flooring AssociationOils and film finishes compared
The 2021 Wood Handbook of the US Forest Products Laboratory compares the two kinds of clear finish: film-forming finishes such as varnish are generally easier to clean and better at keeping wood from getting dirty than penetrating finishes such as oils, which leave the surface texture intact; films can protect against scratches and dents but are worn away by cleaning and abrasion, and floors need thicker, harder films.
“Smooth film-forming finishes, such as varnish, are generally easier to clean and better at preventing wood from getting dirty, compared with penetrating finishes such as oils that leave the surface texture intact. Films, especially when thicker, can also protect the wood from scratches and dents. Films often get worn away by repeated cleaning or by abrasion. Thicker, harder films are needed for high wear applications such as floors.”
Source: Wood Handbook — Wood as an Engineering Material, General Technical Report FPL-GTR-282 (2021), chapter 16 "Finishing of Wood", section "Transparent Finishes" — USDA Forest Service, Forest Products LaboratoryEngineered wood can be refinished, less often than solid
The US National Wood Flooring Association says engineered wood floors are real wood in multiple layers with a top layer of high-quality wood, and that they can be sanded and refinished, but not as many times as solid wood flooring.
“Engineered wood floors are also made of real wood, but include multiple layers, with the top layer made of high-quality wood. … While this type of flooring can be sanded and refinished, it cannot be done as many times as solid wood flooring.”
Source: Types of Wood Floors - woodfloors.org, consumer site of the National Wood Flooring Association (NWFA), 10 October 2023How often a wood floor can be sanded
No trade-association or standards source found puts a number on how often an engineered wood floor can be sanded; the only sourced figure comes from a manufacturer, Kährs, which says engineered floors can be sanded up to four times depending on wear-layer thickness.
| sanding cycles, engineered wood floor (manufacturer statement) | up to 4 times |
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“Depending on the thickness of the wear layer, they can be sanded up to four times, extending their lifespan significantly.”
Source: FAQ about flooring - KährsMulti-layer parquet: a top layer of at least 2.5 mm
EN 13489, the product standard for multi-layer parquet, defines multi-layer parquet as a wood flooring system of laminated construction with a solid wood top layer of at least 2.5 mm, and requires the top layer never to be thinner than 2.5 mm, whatever the production deviation.
| Minimum top layer thickness, multi-layer parquet (EN 13489:2023, 3.1 and Table 1) | 2.5 mm |
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“wood flooring system of laminated construction with a solid wood top layer of at least 2,5 mm thickness … Due to process in production, the deviation of declared top layer thickness can be ± 0,2 mm but the thickness shall be never less than 2,5 mm.”
Source: EN 13489:2023 - Wood-flooring and parquet - Multi-layer parquet elements (SIST preview of the standard, clause 3.1 Terms and definitions, clause 4.1.3 Dimensional characteristics)