Most luxury vinyl plank problems, separating seams, clicking, bouncy spots and broken locking joints, trace back to a floor that wasn't flat enough before installation. Floor prep is the least glamorous part of the job and the most important.
"FLAT" VS. "LEVEL"
- Level means not sloped. A slightly sloped floor is usually fine for LVP.
- Flat means no humps or dips. This is what matters for click-lock floors.
Most manufacturers require the subfloor to be flat within 3/16 inch over 10 feet (some say 1/8 inch over 6 feet). Check your product's installation instructions; ignoring them can void the warranty.
HOW TO CHECK
Lay a 6 to 10 foot straightedge or level in several directions across the room. Slide a tape or shim under the gaps. Mark high spots and low spots with a pencil.
THE FIXES
| Problem | Fix |
|---|---|
| High spots in concrete | Grind them down |
| Low spots or dips | Patch with floor patch or self-leveling compound |
| Whole room out of flat | Pour self-leveler over primer |
| Humps at wood subfloor seams | Sand or plane the seam, re-screw |
| Bouncy or soft areas | Add screws, sister joists or replace subfloor |
BASEMENT SLABS
Basement slabs in the DMV often have dips near floor drains and humps along old control joints. They also need a moisture check. Most LVP is fine over a slab with a vapor barrier, but a damp slab needs its moisture source addressed. See basement flooring options.
WHAT IT COSTS
| Prep | Typical DMV Cost |
|---|---|
| Spot patching and grinding | $1 – $2 / sq ft |
| Self-leveling compound (room-wide) | $2.50 – $5 / sq ft |
| Re-screwing and seam sanding on wood subfloor | $0.75 – $1.50 / sq ft |
| Subfloor replacement areas | $8 – $15 / sq ft |
If an estimate for LVP doesn't mention floor prep at all, ask how they'll handle low spots. A "cheap" LVP install over an unprepared floor often has to be redone.
RELATED READING
LVP PLANKS SEPARATING? CAUSES AND FIXES
Why gaps open at the seams and ends, and the fix for each cause.
SUBFLOOR REPAIR COST: SOFT SPOTS & ROT
Warning signs, 2026 repair costs, and why it has to happen before any new flooring goes down.
BEST BASEMENT FLOORING OPTIONS FOR DMV HOMES
Why below-grade moisture changes everything and which flooring materials actually work in the DMV's humid climate.
Planning a project? See our Flooring Installation service page for scope, process and recent work.
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