How to Install Baseboard and Shoe Over a New Floor
Why this matters
Trim is the last thing the customer sees go on and the first thing that betrays a careless crew. More important to a flooring shop, it is where a good floor gets ruined: one row of shoe nailed down into a floating floor pins its edge, and the floor that was free to move now buckles at the opposite wall or opens gaps down the middle the first winter. Base and shoe do two jobs here, and the second one matters more. They finish the wall, and they hide the expansion space while leaving the floor free to move inside it.
The section that has to come out right
Everything below is in service of one cross-section. The base is fastened to the framing and never touches the floor. The shoe is fastened to the base and only rests on the floor. The floor's edge sits in the gap under them, free.
SECTION AT THE WALL, floating floor shown
stud drywall
| | |
| | | +----+
| | | |base|<- nail into stud, high
| | | | |
| | | | |<- nail into bottom plate, low
| | | | +----+
| | | | |shoe|<- brad into base only
| | | +----+ |
| | | 1/8 gap |<- shoe rests on floor
| | |<->==+=====+===== floor, edge free
| | | 3/8 floor slides under base
+-plate----------------- subfloor --------
The 3/8-inch dimension is the floor maker's expansion space for the example floor below; the shelf default is per the maker, commonly about 1/4 to 1/2 inch. See related: Expansion Space at Walls and Fixed Objects. The 1/8-inch gap is what keeps the base clear of the floor's surface so the floor can slide under it.
The coverage check. Base thickness plus shoe depth is how far from the wall the trim hides the floor's edge. That reach has to be larger than the expansion space plus however far the floor might shrink back from its installed position. Work it before you pick the trim profile, not after it is on the wall.
Before you start
- The floor is finished and the expansion space is clear. Walk the perimeter and pull out any spacer wedge, debris or stray fastener in the gap. A wedge left behind is a fixed point.
- Know what the floor is. Floating floors cannot be fastened through at the edge. A nail-down or glue-down floor will tolerate a shoe nailed into it, but nailing the shoe to the base works for every floor and means the crew never has to ask, so make it the shop's one method.
- Find the framing and what is in it. Mark studs with a finder at a height the base will cover. Note every receptacle box, and look for plumbing walls behind sinks and toilets.
- Trim acclimated with the room. Wood base stored in a cold garage shrinks on the wall and opens its joints. Bring it in with the flooring.
- Pre-1978 house and old painted trim coming off? Removing it is usually covered by the EPA RRP rule (target housing and child-occupied facilities; the small-area minor-repair exemption excludes projects involving demolition, so do not count on it for trim removal) unless testing shows the paint is not lead-based. See related: The Lead-Safe Floor Work SOP.
The procedure, carried through one bedroom
The example room: 12 feet by 14 feet 8 inches, floating laminate just installed, one door. The maker's sheet calls for 3/8-inch expansion space. Trim is primed base 9/16 inch thick in 12-foot lengths, and shoe 1/2 inch deep by 3/4 inch tall. Coverage reach is 9/16 plus 1/2, which is 1-1/16 inches from the wall face. The floor's edge sits at 3/8 inch, so it could shrink back another 11/16 inch before the edge showed. That is comfortably more than this floor will move in one room.
Plan the order around the room. Start on the wall opposite the door and work around so the last joint you make, which is the hardest to fit, is the least seen. The first wall's pieces are square-cut and run tight into both inside corners; each following wall is coped against the one before. Why: a cope is made against an installed profile, so the sequence has to give every cope something to fit to. In the example, the 14-foot-8-inch wall opposite the door goes first.
Lay out any joint over a stud. A 176-inch wall will not come from 144-inch stock in one piece. Here the studs marked at 15-1/4 inches from the left corner and every 16 inches after, so there was a stud center at 127-1/4 inches. The first piece runs from the left corner to that stud, leaving 48-3/4 inches for the second. Cut the joint as a 45-degree scarf, not a butt, with the overlapping piece facing away from the door. Why: a scarf over a stud can be glued and nailed through both pieces into solid wood, so it stays closed when the wood moves; a butt joint between studs opens into a visible line. The next stud, at 143-1/4 inches, would have left only 3/4 inch of spare stock, too tight to recut a bad miter.
Set the base on a spacer, clear of the floor. Slide a 1/8-inch spacer under the base at each nailing point, push the base tight to the wall, and fasten. Why: base sitting on a floating floor bears on it and can pin it, and base sitting tight to any hard floor squeaks against it as it moves. Pull the spacers once the piece is nailed.
Fasten the base into the framing only. Two finish nails at each stud, one high into the stud and one low into the bottom plate, with a nail just long enough to pass the base and drywall and bite about an inch into the framing. In the example that is 9/16 inch of base plus 1/2 inch of drywall, so 2-inch nails. Glue the scarf, then nail through it into the stud. Why: the nail into the plate is what pulls the bottom of the base tight to an imperfect wall. Hazard: stay out of the stud bay beside a receptacle box at the box's height and above a plumbing fixture, run the nailer on its sequential trigger, and keep your free hand out of the line of the nail.
Cope the inside corners on the next wall. Cut a 45-degree inside miter to expose the profile, then saw along the profile line with a coping saw, back-beveled, and clean up with a file. Test it against the installed piece before nailing. Acceptance: no light through the joint, profile tight from top to bottom. Why: a cope stays closed as the wall and the trim move, where an inside miter opens into a dark wedge. See related: How Trim Is Fastened: Baseboard, Casing and Crown.
Scribe where the wall is out. Where the wall bows or the corner is out of square, scribe the back of the base to the wall rather than forcing it with more nails. In the example, the corner left of the door was out enough to open a 1/8-inch gap at the top of the base, so that piece was scribed and planed. See related: Baseboard Scribe-Cutting for Out-of-Square Walls.
Miter and glue the outside corners. Cut both pieces at 45 degrees, test, then glue the miter and pin through it from both faces. Why: an outside corner gets kicked; an unglued miter opens the first time a vacuum hits it.
Install the shoe tight to the floor, fastened to the base. Push the shoe down onto the floor surface so no light shows beneath it, and brad-nail it into the base with the nailer held level or angled slightly upward, never down. Run the shoe's joints over the base's scarfs, coped at inside corners and mitered outside. Acceptance: the shoe sits on the floor with no gap, and pressing down on the floor beside it does not lift or move the shoe. Why: this is the step that separates a flooring installer from a trim carpenter. A brad angled down passes the shoe and goes straight into a floating floor's edge, pinning it. In the example, every brad went level into the base at mid-height of the shoe.
Finish the ends at the door. Run the base into the casing's side and cut the shoe's end on a return or a 45-degree bevel short of the casing, so it does not stub into the jamb. The floor at the door is covered by the transition, not the shoe. See related: How to Undercut Door Jambs and Casing.
Fill, caulk and touch up. Fill nail holes, caulk the joint between base and wall, and caulk the scarfs if paint-grade. Do not caulk the shoe to a floating floor; a bead there glues the edge to the trim. Where the floor maker calls for a flexible sealant at a wet-area perimeter, such as a bathroom, follow that instruction, which is the exception the maker writes.
How the room came out
The opposite wall went up in two pieces with one scarf on the stud at 127-1/4 inches, the two side walls were coped against it and ran square into the door-wall corners, and the door-wall pieces were coped against the side walls and finished at the casings. One piece needed a scribe. Every brad in the shoe went into the base. Coverage was checked once more at the end: the laminate's edge sat at 3/8 inch behind a 1-1/16-inch reach, so the floor can move the full expansion space either way without showing an edge.
What changes the method
Carpet instead of a hard floor. The base is set higher, typically on a spacer that lets the carpet tuck under it, and no shoe is used. The base still goes into framing only.
The customer wants base with no shoe on a hard floor. The base alone must cover the expansion space plus movement. With 9/16-inch base over a 3/8-inch gap there is only 3/16 inch of margin, which a floor shrinking back in a dry winter can use up. Offer a thicker base, a narrower expansion space only if the maker allows it, or the shoe.
Existing base left on the wall. If the new floor went in with the old base staying, the floor's edge has to stop short of the base by the expansion space, and only a shoe covers it. Check coverage the same way: shoe depth alone must exceed the gap plus movement.
Cabinets, stair skirts and fixed objects. Shoe and quarter-round fasten to the cabinet toe kick or the skirt board, never into the floor, and the same coverage check applies.
How to verify the trim is right
Stand in the room in normal light and check that no floor edge shows anywhere along the wall, and that scarfs, copes and miters read as closed lines. Then the floor check: pick three points along the longest wall and press down on the floor beside the shoe with your heel. The shoe should not move with the floor, and the floor should not feel held. Pull one brad's worth of shoe at a scarf if you doubt the angle: the brad should be in the base, not the floor.
References
- The flooring maker's installation instructions, expansion space and perimeter sections
- See related: Expansion Space at Walls and Fixed Objects; How Trim Is Fastened: Baseboard, Casing and Crown; Baseboard Scribe-Cutting for Out-of-Square Walls; How to Undercut Door Jambs and Casing