Flooring guide
Why Does My Floor Feel Hollow?
Learn why floors feel hollow, including floating floor sound, low spots, underlayment, hollow tile, glue-down failure, concrete slab issues, and when to worry.
Useful calculators for this guide
Floating floor movement concept
Quick answer
A floor can feel hollow because it is a floating floor, the subfloor has low spots, the underlayment is changing the sound, tile has poor mortar coverage, glue-down flooring has released, or the concrete slab has surface issues.
Some hollow sound is normal with certain floating floors. Hollow sound becomes more concerning when it is localized, getting worse, paired with movement, or connected to loose tile, lifting planks, cracks, or moisture.
Common causes
Hollow feel is often about support. The finished floor may be spanning a small gap, sitting on cushion, or sounding different because it is not bonded directly to the subfloor.
- Floating floor sound from LVP, laminate, or engineered hardwood.
- Low spots below planks causing flex or drum-like sound.
- Underlayment that is too soft, too thick, or not approved.
- Hollow tile from poor mortar coverage, movement, or bond failure.
- Glue-down flooring releasing from adhesive or subfloor.
- Concrete slab texture, cracks, moisture, or old adhesive affecting bond.
What to check first
Compare hollow areas to solid-feeling areas. If the entire floating floor sounds similar, the sound may be normal for that product and underlayment. If one spot sounds different, moves, clicks, or feels soft, investigate further.
For tile, tap-testing can reveal hollow-sounding areas, but hollow sound alone does not always mean immediate failure. Loose tile, cracked grout, movement, or spreading hollow areas are more concerning.
- Mark hollow areas and see if they grow over time.
- Check for movement, cracks, gaps, lifting, or soft spots.
- Review whether the floor is floating, glue-down, or tile.
- Look for moisture sources near hollow or loose areas.
- Check subfloor flatness if the floor has not been installed yet.
When to call an installer
Call an installer if the hollow area is localized and paired with movement, if tile or grout is cracking, if glue-down flooring is releasing, if moisture is suspected, or if the floor feels soft or unsafe.
A pro can separate normal floating-floor acoustics from a bond, subfloor, or moisture problem.
Example scenario
A floating laminate floor sounds slightly hollow across the entire room but feels stable and has no gaps. That may be normal for the product and underlayment.
In another room, porcelain tile has one hollow spot that later develops cracked grout. That is more concerning because tile should be well-supported by the setting material.