A floor can be beautifully installed and still look unfinished if the transitions and trim aren't right. Transitions are where your new floor meets another floor, a door, a step, a fireplace or a wall. They hide expansion gaps, handle height changes, protect edges and give a clean line.
Why transitions exist
Two reasons:
- Height changes between floors, like LVP meeting tile or carpet.
- Movement, because floating floors expand and contract and need gaps at walls, fixed objects and sometimes doorways.
Glue-down floors move much less and often need fewer transitions, which is one reason they're popular for open floor plans. See glue-down vs click.
The common profiles
| Profile | What it does | Where it's used |
|---|---|---|
| T-molding | Bridges two floors at the same height and covers the gap between them | Doorways between rooms, long runs of floating floor, LVP to LVP or LVP to similar-height tile |
| Reducer | Slopes down from a thicker floor to a thinner one | LVP to sheet vinyl or concrete, LVP to thin floors |
| End cap / threshold | Finishes the edge of a floor against something vertical | Sliding doors, fireplace hearths, exterior thresholds |
| Carpet transition | Joins hard flooring to carpet | Bedroom doorways where carpet stays |
| Stair nose | Wraps the front edge of a step | Stairs and landings, step-downs |
| Quarter round / shoe molding | Covers the expansion gap at baseboard | Along walls when baseboards stay in place |
| Baseboard | Covers the gap at walls, protects walls | Every room |
Many flooring lines sell matching trim pieces, so the color and texture match the planks.
Expansion gaps
Floating floors need a gap, commonly around 1/4 inch but specified by each manufacturer, at walls, cabinets, pipes, door frames and other fixed objects. Many manufacturers also limit how far a floating floor can run in one direction before a transition is needed, and require breaks at doorways in certain layouts. Glue-down floors usually need much smaller gaps, if any. Follow the instructions exactly; a floor pinned by tight trim or cabinets will buckle in summer.
Doorways
The cleanest look in doorways is to run the floor continuously from room to room, which glue-down floors allow and many click floors allow within their run limits. Where a transition is required, place it centered under the closed door so it isn't visible from either room. Door jambs and casings should be undercut so the flooring slides underneath, instead of cutting around the trim profile.
Stairs
Stairs are their own project. Options include LVP with matching stair nose glued to each tread and riser, or new stair treads. Stair installs require secure adhesive bonds and careful fitting, because a loose stair nose is a safety hazard. Old carpeted stairs may have rough or damaged treads underneath that need repair or capping.
Baseboard: remove or keep?
Remove and reinstall (or replace)
Removing baseboard before installing gives the cleanest look: the flooring goes under where the baseboard was, and the reinstalled baseboard covers the expansion gap without quarter round. It's more work, and old baseboards can crack coming off. In older homes, removing painted baseboard may disturb lead paint; see lead-safe renovation.
Leave it and add quarter round
Leaving baseboards in place and adding quarter round or shoe molding is faster and avoids wall damage. It looks more traditional and adds another piece to paint or stain.
New baseboard
New flooring is a natural time for new, taller baseboard. Paint new baseboards before installation, then do a final coat or touch-up after. See project order.
Caulk and finishing details
Caulk the top edge of baseboard to the wall for a clean line before the final paint coat. Don't caulk floating floors to baseboard or trim, because that pins the floor. In bathrooms and kitchens, some manufacturers call for a flexible sealant at tubs, showers and around plumbing; follow their wet-area instructions.
Planning trim quantities
Measure the perimeter of each room, subtract door openings and add a waste allowance for cuts and miters. Count doorways for transitions and steps for stair nose. Our project planner gives you a starting estimate for baseboard and quarter round.