Hardwood Floor Sanding, Sioux City Metro
Floor sanding is the part of hardwood floor refinishing that takes a floor down to bare wood so a new finish can bond to it. What grit the final sanding pass should stop at isn't arbitrary — it's set by whichever finish system is going down afterward, and current manufacturer data sheets are specific about it.
Coarse to fine, in stages
A USDA Forest Products Laboratory and Purdue University extension publication on finishing and maintaining wood floors describes the underlying method as sanding "in successive cuts from coarse to fine" — typically two cuts, or a third if the floor is uneven (USDA FPL / Purdue, Finishing and Maintaining Wood Floors, 1980). The same source is explicit that a sanding job should remove no more of the floor than necessary: "Do not remove more wood than absolutely necessary." That principle is also why a floor's actual thickness matters before sanding starts. Most strip flooring runs about ¾ inch thick, which the publication says lets it "withstand a number of sandings" over its life, but a thinner floor or hardwood plywood needs more caution to avoid sanding through the wear layer — its thickness can usually be checked by pulling a floor heating register, or the shoe mold and baseboard, to expose a cut edge (USDA FPL / Purdue, 1980).
Grit sequence by finish system
Two current manufacturer technical data sheets, downloaded directly from the manufacturers' own sites, give specific final-cut grit ranges for the finish that will follow:
| Finish system | Final sanding cut | If more than the recoat window passes between coats |
|---|---|---|
| Bona Traffic HD, floor will be stained | 80–100 grit, then a multidisc pass at 80–120 grit | 180–240 grit, if more than 48 hours pass between coats |
| Bona Traffic HD, floor stays unstained/natural | 80–120 grit, then a multidisc pass at 120–150 grit | 180–240 grit, if more than 48 hours pass between coats |
| Minwax Super Fast-Drying Polyurethane (oil-based), new floor to be stained or sealed | No higher than 100 grit | Lightly sand at 220 grit if more than 10 hours pass before the next coat |
| Minwax Super Fast-Drying Polyurethane (oil-based), no stain or sealer | No higher than 120 grit | Lightly sand at 220 grit if more than 10 hours pass before the next coat |
| Minwax Super Fast-Drying Polyurethane, previously finished floor in good condition | Light sand at 120 grit | — |
Sources: Bona US, Technical Data Sheet, Bona Traffic HD, dated May 27, 2026 ("replaces all previous versions"); Minwax, Technical Data Sheet, Super Fast-Drying Polyurethane for Floors 350 V.O.C., Rev. 1, dated January 30, 2026. Minwax's data sheet also notes that a "previously finished" floor being prepared this way needs to be "in good condition (no chipping, peeling, worn areas or residue)" — a floor with more damage than that is a repair or refinishing question first; see restoration and repair.
A third product, Minwax's Ultra Fast-Drying Polyurethane for Floors (a water-based finish), doesn't specify a sanding grit on its own data sheet, but does call for a light 220-grit sand if the window between coats is missed (Minwax, data sheet, as of 2026). Grit numbers from one manufacturer's finish system shouldn't be assumed to carry over to a different product — each row above is what that specific data sheet states, not a general "water-based" or "oil-based" rule.
What determines whether sanding is even an option
Sanding removes a thin layer of wood every time it's done, and how many more sandings a given floor has left in it depends on the floor's own history and construction, not a fixed number. NWFA's own consumer-facing materials are direct about this: "the number of times a floor can be sanded varies depending on a variety of factors including the skill of the contractor, the equipment used, the thickness of the wear layer, the flatness of the floor and the condition of the floor," and NWFA gives no set count (NWFA, "Refinishing Your Floors," woodfloors.org, as of 2026). A separate NWFA publication, its 2020 Consumer Outreach Toolkit, adds that "most wood floors can be sanded and refinished several times during their service lives" without putting a number on "several," and notes that a professional refinisher typically removes "very little of the wood to make repairs – generally 1/32" or less" per sanding (NWFA, Consumer Outreach Toolkit, 2020). Those two figures — an unspecified "several" and a rough per-sanding removal estimate — are the extent of what NWFA's own consumer materials commit to; a specific count, wherever it turns up elsewhere, isn't something this description relies on.
Solid wood flooring is the kind that supports repeated sanding over the years. NWFA distinguishes it from engineered wood flooring: it "can be sanded and refinished," but according to NWFA "it cannot be done as many times as solid wood flooring," because only part of an engineered floor's top layer is solid wood (NWFA, "Types of Wood Floors," as of 2026). Whether a specific engineered floor qualifies for sanding at all typically comes down to its wear-layer thickness, which is a question worth raising before assuming a floor can be sanded the same way solid strip flooring can.
Sanding and the rest of the job
Sanding is a step inside the larger hardwood floor refinishing process, not a standalone service on its own — it sets up whatever comes next, whether that's a stain and color change or a clear finish straight over bare wood. A floor that only needs its top finish layer refreshed, without sanding down to wood, is a screen and recoat question instead. For homeowners weighing a full resand against other options, refinish or replace covers wear-layer thickness and when a floor may no longer be a sanding candidate, and water-based vs oil-based finish covers how the finish choice affects the process described above.