Quick answer
Fix squeaky floorboards by eliminating movement between the subfloor, joists, and finished flooring. The most reliable methods are: driving screws to secure the subfloor to joists, shimming small gaps from below with glue, using a breakaway screw kit under carpet, and lubricating minor board-to-board squeaks on hardwood. Access from below (basement/crawlspace) makes the job easier and cleaner.
Why floors squeak
- Loose nails or insufficient screws allow the subfloor to rub against joists.
- Seasonal wood movement shrinks boards, letting fasteners move.
- Gaps between joists and subfloor develop over time.
- Board-to-board friction in hardwood floors (especially with dry winter air).
Tools and materials
- Stud/joist finder, painter’s tape, pencil
- Drill/driver with bits and countersink; impact driver optional
- Wood screws: #8 or #9, trim-head or bugle-head (2\u2013\u00bd in. typical)
- Breakaway screw kit for carpet: Squeeeeek-No-More or Counter-Snap
- Construction adhesive (subfloor rated) and wood shims
- Wood glue, powdered graphite or talc, putty/wax stick to match floor
- Pry bar, rubber mallet, utility knife
- Safety glasses, dust mask, knee pads, hearing protection
Estimated cost: $10\u2013$50 depending on method. Time: 15 minutes for a small spot; 1\u20132 hours for multiple locations.
Step-by-step fixes
1) Find the exact squeak and the joist
- Walk the area and mark noisy spots with painter’s tape.
- Use a stud/joist finder to locate joists. Most joists are 16 in. on center.
- Have a helper step while you feel for deflection or listen from below if possible.
Specs & spacing:
- Joists: commonly 16 in. OC (sometimes 24 in.)
- Screw length (from above): 2-1/2 in. for 3/4 in. subfloor into joist
- Screw spacing: start with 6\u20138 in. around the squeak area
- Pilot hole: 3/32 in. for #8 screws in hardwood
2) Best method if you have access from below (basement/crawlspace)
- Inspect under the squeak while someone steps on it. Look for a gap between subfloor and joist.
- Slide a wood shim with a dab of wood glue into the gap until it just snugs up. Do not force it; over-shimming can hump the floor above.
- Run a 1/4 in. bead of construction adhesive along the joist where it meets the subfloor on both sides of the area.
- If there’s substantial movement, sister a short 2x4 block alongside the joist and screw the subfloor into the block from below with 1\u20141/4 to 1\u20141/2 in. screws, set to not penetrate the finished floor above.
Tip: A headlamp and a right-angle drill help in tight bays.
3) Fix on hardwood or exposed flooring from above
- Locate the joist. Drill a pilot hole and drive a trim-head screw through the flooring, subfloor, and into the joist. Countersink slightly.
- Test the squeak. Add one or two more screws 2\u20136 in. away if needed.
- Fill the tiny hole with color-matched putty or a wax fill stick and buff.
For board-to-board squeaks (not over a joist):
- Sprinkle powdered graphite or talc into the seam and work it in with a putty knife. Step on the area to draw the powder down. Wipe clean.
- For small gaps that chatter, wick in wood glue, then clamp using blue tape and opposing wedges; remove excess and let cure overnight.
4) Fix under carpet without removing it
Use a breakaway screw system (Squeeeeek-No-More or Counter-Snap):
- Find the joist through carpet using the included alignment tool or a joist finder.
- Drive the special screw through the carpet and pad into the subfloor/joist.
- The screw head snaps off below the backing, leaving carpet intact.
- Check and add a second screw if the squeak persists.
This takes 10\u201320 minutes per squeak and is nearly invisible.
5) If the entire room squeaks
- Add screws every 8 in. along joists across the squeaky area (from above if you plan to refinish, or from below with blocks as described).
- Beads of construction adhesive along every joist/subfloor interface also help dampen movement.
Safety considerations
- Before driving long screws, confirm joist location to avoid missing and piercing utilities. If uncertain about wires/plumbing, open a small inspection hole from below first.
- Wear eye and hearing protection when drilling. Use a dust mask when applying powders.
- If you have radiant floor heating, do not drive screws from above without knowing tube locations. Consult plans or a pro.
Tips for best results
- Use screws, not nails. Screws hold tension and won’t back out.
- Pre-drill hardwood to prevent splitting and ensure a clean countersink.
- Work from the loudest spot outward, testing between each screw. Often one well-placed fastener solves it.
- Control humidity (30\u201350%). Stable moisture reduces seasonal squeaks.
- Keep a small assortment of trim-head screws (#7\u2013#9) and a countersink bit on hand.
Common mistakes to avoid
- Over-driving a shim and lifting the floor.
- Using oil or silicone sprays on hardwood seams; they can stain and interfere with future finishing.
- Driving screws without locating the joist; you’ll miss the structure and still have movement.
- Using screws that are too long when working from below and popping through the finished floor.
When to call a professional
- Large areas with bounce or sag; you may have undersized or damaged joists.
- Evidence of water damage, rot, insect activity, or delamination of subfloor.
- Historic or valuable hardwood flooring where you want invisible repairs.
- Homes with radiant heat or complex wiring/plumbing paths near the squeak.
Rough tool picks
- Drill/driver with adjustable clutch (ToolStash: compact 12V is fine for this).
- Trim-head wood screws 2\u20132-1/2 in. (#8/#9).
- Construction adhesive labeled for subfloors.
- Breakaway screw kit for carpeted floors.
- Hardwood repair putty and powdered graphite.
Tackling a squeak is usually a low-cost, high-satisfaction project. Start with careful locating, choose the least invasive method for your floor type, and lock the subfloor to the structure with well-placed screws or shims.