Read time: 7 minutes  |  By: YUPSENI Team

A well-planned transition keeps two rooms looking like one continuous space - and prevents warping, gaps, and cracks later.

1. 1. Why the Gap Between Two Floors Exists
2. 2. How Wide the Expansion Gap Should Be
3. 3. Leveling SPC Flooring With Tile or Stone
4. 4. Three Ways to Connect Two Floorings
5. 5. How to Choose the Right Method

The moment a floor looks wrong is rarely the pattern. It is the seam.

Choosing a beautiful SPC flooring pattern is easy. Getting the surface to flow cleanly from one room to the next is where most DIY projects fail. And the most common mistake is a simple one: leaving no gap between the two floorings.

Every rigid floor covering expands and contracts with temperature. When a room heats up, the flooring grows slightly. If it is butted hard against an adjacent material, there is nowhere for that growth to go. The result is warping, buckling, or a visible crack along the seam. This is why a thermal gap is not optional - it is the reason the transition looks good years later.

The gap itself is invisible once a transition strip or sealant sits on top. It is the empty space underneath that does the work. For a deeper look at how much space floors need at walls, the expansion gap guide covers the full rule set.

The size of that hidden gap depends on what is on the other side of the seam. There are two broad categories.

Static materials - porcelain stoneware, ceramic tile, and stone. These do not move with temperature. When SPC flooring meets these, a gap of at least 5 mm is needed.

Free-standing materials - parquet boards and laminate. These expand and contract just like SPC. Between two moving surfaces, the gap has to be wider, at least 10 mm.

If you skip this step, both floors will press on each other, and the whole strip between the rooms becomes a swelling line. In practice, the gap is one of the installation steps most installers rush, and the one that shows up first as a defect.

Aesthetics demand that both surfaces sit at the same height. That is where the trouble starts, because the two materials rarely have the same thickness.

Porcelain stoneware is usually around 10 mm thick. A typical quartz vinyl / SPC plank comes in at around 5 mm. That is a 5 mm drop at the door - enough to trip someone and enough to make any transition strip look awkward.

The cleanest fix is a self-leveling compound, poured over the lower side to raise the SPC floor up to the tile level. You can also use thicker underlayment or a two-stage transition profile if the difference is small. The goal is the same: both floors at the same plane so the threshold sits flat and the eye travels smoothly across.

Raising the SPC side with a self-leveling compound removes the step between rooms.

Once the gap is sized and the levels are matched, you choose how to close the seam. There are three standard options.

4.1 Transition strips and threshold profiles

The most common and most flexible option. A threshold or joining profile sits over the gap, hides the empty expansion space, and - crucially - allows the floors to keep moving under it. Unlike sealant or cork, many profiles also tolerate a difference in level between the two sides, so you can use them even when the floors are not perfectly flush.

4.2 Sealant

Sealant is the most seamless look. It can be matched to the floor colour, so the joint nearly disappears. Because it is flexible, it absorbs the thermal expansion of the coatings and stops cracks from forming along the seam. The one hard requirement: both surfaces must sit at exactly the same level. If there is any height difference, sealant will tear.

4.3 Cork expansion joints

Cork strips sit in the gap and compress as the floor expands, making the joint look finished without a metal or plastic profile. It has the same level requirement as sealant - both floors need to be flush. It is a natural, soft finish that suits wood-look rooms especially well.

If the two floors are at the same height, sealant gives the cleanest, most invisible finish. If you want a natural look and same height, cork is the better choice. If there is any height difference between the rooms - which is the common case - a threshold or joining profile is the only option that will not fail. It hides the step and lets the floors keep their gap.

The decision comes down to one question: are the two floors at the same level? Yes → sealant or cork. No → transition strip. Get that right, and the joint stays clean for years.

If you are still comparing materials before the job, the full SPC vs wood vs tile comparison shows what sits on each side of that seam.