Floor Transitions Between Rooms: Levels and Profiles

How different floor coverings meet at doorways and in open-plan spaces: matching levels, expansion gaps, types of profile and where to place the line.

An apartment usually has several floor finishes: tiles in the bathroom and kitchen, parquet or laminate in the rooms, sometimes natural stone at the entrance. The line where they meet looks like a small detail, but it is one of the most noticeable spots in daily life. A threshold that catches your toe, a gap under the door or a profile that lifts over time all show that this detail was not thought through early enough.

Where level differences come from

Every floor finish has its own build-up. Tile plus adhesive has one thickness, laminate with underlay another, and solid parquet something different again. If the screed is poured at the same level throughout the apartment, the finished floors will not meet flush.

This is prevented at the planning stage. For each room the full thickness of the chosen finish, including underlay, adhesive and any waterproofing, is calculated, and screed levels are set accordingly. The aim is for all finished floors to meet on one plane.

In bathrooms a small step or raised threshold is sometimes kept deliberately so that water does not run into the hallway. That is a design decision and should be resolved together with the floor drain and the falls.

Why an expansion gap is needed

Floating floors such as laminate and parquet expand and contract with temperature and humidity. When they run uninterrupted from one room to the next, movement builds up over the long run, joints open and the floor can lift. That is why manufacturers usually require an expansion gap at doorways and after a certain length.

Where tiles meet a timber-based floor, the gap matters even more: tile does not move, parquet does. The flexible space between them stops the two materials pushing against each other.

Types of transition profile

The gap should not be left open, and there are several ways to cover it and protect the edges:

• a flat connecting profile for floors at the same level;
• a ramped or compensating profile for a small height difference;
• an end profile where the floor meets a wall, a step or an open edge;
• a concealed profile or cork strip when the joint should be almost invisible;
• a metal strip to protect a tile edge and create a crisp line.

Profiles glued or screwed on top are easy to fit but sit slightly proud of the floor. Flush concealed profiles look better but must be installed as the floor is laid; adding them later is difficult.

If the household includes an elderly person, a small child or someone using a wheelchair or pushchair, perfectly flush transitions matter even more. A lip of just a few millimetres can catch a foot, stop a robot vacuum or jolt a wheel. In such homes it is better to level the floors at the screed stage than to look for a ramped profile afterwards.

Where the transition line should go

In rooms with doors, the transition sits under the door, where it will not be seen when the door is closed. If the door opens inwards, the line is usually aligned with the face of the closed door leaf, so that from each room you see only that room's floor.

Open-plan spaces have no doors, so the transition becomes a design element. Where kitchen tiles meet living-room parquet, the join is usually placed along the edge of the island or the base cabinets. A line in a random place, for example cutting through the dining table, makes the space feel fragmented. Curved or wavy transitions are possible too, but they need precise cutting and a flexible profile.

Planning checklist

To avoid problems with transitions, settle these points in advance:

• the type and full thickness of the finish in every room;
• screed levels and the decision on a water stop at the bathroom;
• which way doors open and where the frames sit;
• in open plans, how the boundary relates to furniture and the island;
• profile colour: matching the floor, the doors or the metal details;
• if there is underfloor heating, how its zones line up with the transition.

Because doors are fitted after the floor, the gap under the door leaf must also be calculated from the final floor level.

In apartment renovations Zaferoğlu İnşaat calculates floor levels at the design stage so that transitions bring no surprises at handover. If you want thresholds without steps, we can calculate the floor levels with you before the screed goes down.