What is the maximum floor length I can install without expansion joint?

If your room size does not exceed 13x13 meter, you don't need to add an extra expansion joint. If it exceeds 13 running meters however, we strongly advise to do so.

The maximum length of laminate flooring you can install without expansion joint mainly depends on two things:

  • the shape of the room in which the floor will be laid
  • the climate conditions in that room

A Pergo laminate floor is mainly composed of natural wood and will naturally expand and contract upon changes in the relative humidity. The dimensional variation of the installed floor will almost be equal in length and width. At 20°C and a relative humidity, RH, between 40-60%, the movement is minimal. Pergo laminate flooring is produced and delivered with a moisture content to cope with a RH between 30-60%. 

In a dry climate, the RH might drop below 30% during winter  and rise above 70% in summertime. This will create movements in the floor surface. To secure enough clearance for the natural movements and to avoid possible open joints, squeaking etc. always keep a dilatation joint of 5 mm to walls, thresholds, staircases, pipes etc. during installation. Use the spacers in the installation kit to help you.

Installing in very dry or very damp conditions

Installing in winter time in very low RH, the clearance to the wall should be lowered to 3mm since the floor panels will shrink. If installing in high RH climate the clearance should be raised to 8mm since the floor panels will expand. The clearance must be left open and may NOT be filled by any sealant, silicone or other adhesive. Never fasten the floor with nails, glue, screws or in any other way.

Installing big surfaces

If the surface to cover is bigger than 13 running meters, you should add an extra expansion joint of 15 to 20 mm. It is also recommended to add expansion joints under the doors between rooms to separate the rooms. 

If the floor is laid with a length of more than 10 running metres, from one room to another - across a corridor for example - then this could lead to tension and possible distortion (upward warping) of the floor. This might occur when one room is heated and the other is not or when there is for example a piece of heavy furniture in one of the rooms. We therefore recommend separating some of the rooms from the rest by creating expansion joints under the doors between rooms.

5-in-1 moulding

A Pergo 5-in-1 moulding is a perfect solution in these situations. This moulding can also take care of transition as well as finishing edges against vertical surfaces such as thresholds, sliding door frames etc.. 

When in doubt, contact us or your local Pergo dealer.