Every floating floor install needs a transition somewhere, and nine times out of ten the right answer is a t moulding — a T-shaped strip that caps the expansion gap between two floors of the same height. Done correctly, it is invisible from a standing perspective; done badly, it catches every vacuum and curls at the edges within a year. The trick is picking the right material for the two floors being joined and setting the track at the exact gap width the floor manufacturer specifies.
What a T Moulding Is and Is Not
A T moulding looks like a capital T in cross section. The vertical leg drops into a gap between two floors and clips or glues into a track, while the horizontal top rides flush across both floor surfaces. It is only used when both floors are the same finished height, within about 1/8 of an inch.
If the two floors are different heights, you need a reducer (slopes from a higher floor to a lower one), a threshold (joins a hard floor to carpet), or an end cap (finishes a hard floor at a doorway to carpet). Using a T moulding where a reducer belongs is the single most common mistake on DIY laminate installs.
When You Need One
Floating floors — laminate, luxury vinyl plank, engineered hardwood with click systems, and cork — all expand and contract with humidity. The manufacturer gives you a maximum continuous run before a break is required, and in doorways, hallways, and long living-room-to-kitchen transitions, you cap the resulting gap with a T moulding.
- Laminate: 40-foot maximum continuous run in either direction, per most warranties.
- LVP/SPC: Typically 30-50 feet, varies by brand. COREtec allows 100 feet. Shaw usually caps at 40.
- Engineered wood floating: 40 feet in most residential products.
- Doorways under 36 inches wide: Always use a T at the threshold regardless of run length.
Metal, Vinyl, or Wood T Moulding
The three common materials each solve a different problem.
Metal T mouldings — usually aluminum with a brushed nickel, satin bronze, or polished chrome finish — are the most durable for commercial use and high-traffic entries. Schluter Reno-T and MD Building Products Pemko lines run $18 to $35 per 72-inch piece. They install into a clamping track and never curl.
Vinyl T mouldings are the cheapest at $6 to $14 for a 72-inch length and are color-matched to specific laminate or LVP collections. They install into a plastic or metal track screwed into the subfloor. The downside: vinyl softens in direct south-facing sunlight and can get scuffed by wheeled appliances.
Wood T mouldings match hardwood floors exactly and give the most premium finished look. Expect $25 to $60 per 78-inch piece in domestic species like red oak, up to $90 for walnut or maple. Wood T molding requires staining, finishing, and careful miter cuts, which puts it firmly in the intermediate DIY category.
Track Installation Step by Step
Most residential T mouldings use a two-piece system: a metal or plastic track screwed into the subfloor, and the visible T that snaps or glues into the track.
Start by centering the track in the expansion gap between the two floors. The gap should be 1-1/8 to 1-1/4 inches wide for a standard residential T. Pre-drill through the track every 8 inches, drop a 1-inch screw, and countersink until the track sits flush with the subfloor. Snap the T into the track by pressing down firmly along the entire length — you will hear a click when each inch engages. For the last 2 inches at walls, use a rubber mallet with a tap block to seat the T without scratching the top surface.
Cutting to Length
Measure the opening, subtract 1/8 inch for seasonal movement, and cut the T with a fine-tooth miter saw. For metal T, use a 60-tooth carbide non-ferrous blade and cut slowly to avoid burrs. For vinyl, a standard wood blade at reduced feed rate works cleanly. For wood T, a 40-tooth ATB blade leaves a glass-smooth cut.
File or deburr all cut ends on metal before installation. A sharp metal edge at a bedroom doorway will shred socks and catch toes within a week.
Doorway Transitions and Door Clearance
The top of a T moulding sits about 1/2 inch proud of the finished floor. In a doorway, that means you may need to trim the bottom of the door by 3/8 to 1/2 inch to clear the T. Measure before you install — I’ve seen plenty of homeowners finish the T and then realize the bedroom door jams on every swing.
Common Mistakes to Avoid
Nailing the T directly to the subfloor kills the expansion gap and guarantees peaking and gapping in the adjacent floor. The track must float; the floors under the cap must float. Gluing a T onto concrete works only with specific urethane adhesives and only when both adjacent floors are solid glue-down installs, which is rare.
Using a T moulding to cover a gap larger than 1-1/4 inches also fails — the horizontal top rides on air at that point and flexes under foot traffic. If your gap is oversized, either rip a strip of matching floor to narrow it or order an extra-wide T specifically designed for 1-1/2-inch gaps.
Buying Tips
Always order the matching T moulding from the same lot as your flooring. Color and grain patterns drift from lot to lot, and a T from an earlier production run will stand out under any light. If you are working with a discontinued floor, check eBay and Facebook Marketplace for leftover boxes — a single bundle often has a matching T in it. For metal T, stick to Schluter or Pemko for any install you care about long term.
