Baseboard Installation with New Floors: Styles, Heights, Materials and Method

Baseboard installation is the last step of a new floor and one of the first things people notice. Good trim makes a floor look finished. Gappy corners, nails in the wrong place or a board pressed down on a floating floor do the opposite, and the last one can damage the floor. This guide covers whether to reuse or replace your baseboards, how to choose baseboard height and style, which material suits each room, and how baseboards are installed properly with a new floor.

Baseboards and new flooring: the order of work

With a new floor, the order is simple. The old baseboards come off, the floor goes in with its expansion gap at the walls, and the baseboards go on last. The baseboard then covers the gap and sits at the right height for the new floor.

The alternative is to leave the old baseboards in place and add quarter round or shoe moulding to cover the gap. That is faster, but it adds a second line of trim. Our guide to quarter round vs baseboard compares the two approaches and explains how to take baseboards off without damaging the wall. This guide assumes the baseboards are coming off, and covers what goes back on.

Trim is also the moment to deal with door casings and transitions. Casings are undercut before the floor goes in, so the flooring slides under them. Transitions at doorways go in with or after the floor; see floor transition strips. When all three are planned together, the room looks deliberate rather than patched.

Remove and reuse, or replace the baseboards

Reusing baseboards saves material, and it is the right call for good solid wood trim or original profiles that would be hard to match. It works best when the trim comes off cleanly, the new floor is close to the old one in thickness, and you like the existing style.

Replacing is often the better choice. Old MDF often cracks or crumbles at the nails when it is pried off. Painted trim may have years of drips and dents. A thicker new floor can make an old, short baseboard look even shorter. Many people also want a taller or more modern profile with the new floor, and a new floor is the easiest time to change it.

A middle path is common in older homes: reuse the original trim in the main rooms, and replace it where it is damaged or where no original survives. Number every piece as it comes off, so it goes back where it came from.

Baseboard height: how tall should baseboards be?

Baseboard height is mostly about proportion. A tall baseboard in a small room with a low ceiling looks heavy. A short one in a large room with a high ceiling looks thin and builder-grade. There is no code rule, only rules of thumb.

A common rule of thumb is around 3" to 5" for rooms with 8 ft ceilings, around 5" to 7" for 9 ft to 10 ft ceilings, and taller again for higher ceilings. Many newer Ottawa homes with 9 ft main floors use something in the middle of that range. Basements with lower ceilings often look better with a slightly shorter board than the main floor.

Three other things affect the choice:

• The door casing. The baseboard should be slightly thinner than the casing, so it stops neatly against the casing's edge rather than sticking out past it.
• The rest of the house. If only some rooms get new trim, match the height and profile of the trim in the rooms you can see from them.
• Outlets and vents. A much taller board can run into low outlets or floor registers, which then need to be moved or worked around.

Before deciding, hold a sample length against the wall in the room. Tape a strip of paper at the height you are thinking of, and live with it for a day. It is a cheap way to avoid an expensive mistake.

Baseboard styles

Baseboard styles fall into a few families, and the right one follows the style of the house and the door casings.

Flat or modern. A plain board with a square top edge, or a small bevel or eased edge. It suits contemporary homes, condos and minimal interiors. It is also forgiving to paint and easy to keep clean. Flat baseboard shows wavy walls more, though, because there is no profile to soften the line.

Colonial. A board with a shaped top edge, usually a combination of curves and steps. It is the classic look in many Canadian houses from the last few decades, and it comes in many heights.

Ogee. Named for its S-shaped curve along the top edge. It is softer and more traditional than a plain colonial, and suits older or more formal rooms.

Craftsman and built-up. A tall flat board with a separate cap along the top, sometimes with a shoe at the floor. Many older Ottawa homes have built-up trim like this, and it can be recreated with stock pieces.

Whatever the style, use the same profile through connected rooms, and match the casings.

MDF vs wood vs PVC: choosing the material

Four materials cover almost every home. Each has a place.

MDF is the usual choice for painted trim in dry rooms. Its weak point is water: once it swells at the bottom edge, it doesn't go back. Finger-jointed pine, short pieces of pine glued end to end, is tougher at the corners and holds nails better, but it is paint grade only. Hardwood is for stained trim that matches a wood floor, stairs or doors. PVC is the safe choice near tubs and toilets and in basements on a slab, where a leak or high humidity is possible; see the best basement flooring for the floor side of that decision.

Before you install: buying, acclimating and pre-finishing

Buy lengths that cover each wall in one piece where possible, plus extra for corners, mistakes and the odd bad board.

Wood trim moves with humidity, like a wood floor. Bring it into the house a few days before installation and store it flat. In an Ottawa winter, trim from a cold or damp space can shrink as it dries in a heated house, which opens joints after installation.

Many installers prime and paint the trim before it goes on, with one coat of the finish colour. Painting a flat board on sawhorses is faster and neater than painting it on the wall. After installation, only the nail holes, caulk line and a final coat remain. Painting is often done by the painter on the job; ask your installer what is included.

How baseboard installation is done

A careful installer works around the room in an order that makes each joint easy to fit. Here is how it typically goes.

1. Mark the framing. Find and mark the studs on each wall with a stud finder, and remember the bottom plate, the horizontal framing member along the floor.
2. Plan the order. Start with the wall facing the door, with both ends cut square into the corners. Each following piece is coped to fit against the one before it. The last piece is ideally on a wall that is least visible.
3. Cope inside corners. Cut the piece at a 45-degree inside mitre, which exposes the profile on its face. Then cut along that profile line with a coping saw, angled back, and refine it with a file. The coped end sits over the face of the first piece like a puzzle.
4. Mitre outside corners. Measure the actual angle, because outside corners are rarely exactly 90 degrees. Cut each piece at half that angle, glue the joint and pin it from both sides.
5. Join long runs with a scarf joint. Where one length isn't enough, overlap two pieces with matching angled cuts over a stud, glued and nailed.
6. Nail into framing. Use finish nails long enough to pass through the drywall into the studs, commonly one higher into the stud and one lower into the bottom plate at each stud.

Coping is the mark of good trim work. Inside corners in real houses are rarely square, and a mitred inside corner opens into a gap as the house moves through the seasons. A coped joint stays closed, because one piece rests against the face of the other. It takes more time, but it lasts.

Walls and floors are never perfectly straight either. Where the floor dips, the baseboard may need to be scribed: traced to the floor's line and trimmed so it follows it without a gap. Where the wall bows in, a little shimming or an extra nail pulls the board to it. Tall, flat baseboard is the least forgiving of crooked walls, so these details matter more with modern profiles.

Concrete walls and steel studs, common in condos, don't hold ordinary nails well. There, baseboards are usually fixed with construction adhesive and pin nails. Our condo flooring rules guide explains why many buildings also want the floor isolated from the walls for sound.

Leaving the floor free to move

The most important rule with a new floor is that the baseboard is fixed to the wall, not the floor. Floating floors, such as laminate, click vinyl plank and floating engineered wood, expand and contract with the seasons. They need their gap at the walls, and the baseboard hides that gap without touching it.

Over a floating floor, the baseboard sits lightly on the floor or a hair above it. It is never pressed down hard and never nailed down through the floor. If it pins the floor at the edge, the floor can peak at the joints or open gaps elsewhere. Our guides on how to install laminate flooring and how to install vinyl plank flooring explain the expansion gap in detail.

Nail-down hardwood is fixed to the subfloor, but it still moves with humidity, so it gets the same treatment. Glue-down vinyl moves less, and the baseboard can sit right down on it. With carpet, the baseboard is usually set a little above the subfloor so the carpet and pad can be tucked under it. In each case, install the floor first, and set the trim to the finished floor, not to the subfloor.

Don't caulk the bottom of the baseboard to a floating floor, either. Caulk bonds the floor to the trim and pins it, just like a nail does.

Baseboards with tile floors

Tile floors are finished at the walls in one of two ways. The first is a wood, MDF or PVC baseboard installed after the tile. The second is a tile base: strips cut from the floor tile, or a matching base piece, set on the wall above the floor.

Either way, the gap between the floor tile and the wall stays free of mortar and grout. Tile needs room at its edges for movement, and industry practice calls for perimeter joints at walls and other fixed surfaces. Our guide to tile movement joints explains why. A baseboard simply covers that gap. With a tile base, the joint between the base and the floor tile is filled with a flexible sealant, not grout.

A tile base suits bathrooms, entries, mudrooms and commercial spaces, where mops and wet boots would swell MDF. Its top edge is usually finished with a factory edge, a bullnose piece or a slim metal profile; our tile edge trim guide compares the options. The full tile floor process is in how to tile a floor.

Caulk, filler and paint

The finishing steps are what make painted trim look seamless. Nail holes are filled with wood filler or painter's putty and sanded flush. The top edge, where the baseboard meets the wall, gets a thin bead of paintable caulk to hide the small gaps that every wall has. Coped and mitred corners can take a touch of caulk or filler too, as long as the joint is already tight.

Caulk is a finishing product, not a repair. A thick bead hiding a wide gap cracks and shows as the house moves. If a corner is open, it should be recut.

Stain-grade trim is finished differently. Nail holes are filled with a coloured putty after the finish coat, and caulk is used sparingly, because it doesn't take stain. Stain-grade work also needs tighter joints from the start.

Common baseboard installation mistakes

• Nailing trim down into a floating floor, or caulking it to the floor.
• Mitring inside corners that open up within a season.
• Nailing only into drywall, so the trim pulls away from the wall.
• MDF in wet rooms, which swells at the bottom edge.
• A baseboard thicker than the casing, which sticks out past it at every door.
• Setting trim to the subfloor before the floor is in, leaving it too low or too high.
• Butt joints in the middle of a wall instead of scarf joints over a stud.

Most of these come from rushing the last day of a job. Trim is fine work, and it rewards patience.

DIY baseboard installation or hiring a pro

Baseboard is one of the more approachable finishing jobs for a careful DIYer. A mitre saw, a coping saw, a stud finder and a finish nailer cover most of it, and a simple room with painted MDF is a good place to learn. It gets harder with stain-grade wood, crooked walls, plaster, built-up profiles and many outside corners.

In older homes, plaster and old adhesives may contain asbestos, so have suspect materials tested before you disturb them.

The cost depends on the linear footage, the height and material of the board, the number of corners and doorways, and whether old trim is removed, reused or replaced. See flooring cost in Ottawa for the floor itself. Agora installs baseboards, quarter round and transitions as part of a flooring job or on their own. Our baseboards and trim page shows what is included.

Frequently asked questions