The Shrinking Season and Timber

Timber expands and contracts. Some finishes really highlight this while others don't tend to highlight the effect. Plastic finishes crack as the boards move and this creates white lines between the boards. Polyurethane bridges the gaps in coating and then is stressed as the timber moves. OSMO is different - It looks good from season to season.

OSMO is a great choice because it doesn't highlight the movement. It protects the boards and yet allows the boards to move freely. 

Seasons change. Humidity rises and falls. Temperatures rise and fall. Therefore solid floorboards move.  A floor will not always look exactly the same from season to season due to a small amount of movement.  However this is natural and to be expected.  Because timbers vary in density and structure, some timbers will give slightly more movement than others. However movement in a floor does not have to be major and is usually no cause for alarm.

One of the most basic requirements of a timber floor is the expansion gap which is placed around the perimeters of the room.   A 10 to 15 mm gap is left around the room to allow for some expansion in the timber.  Timber expands at a rough ratio of 50 times greater across its width than its length and therefore there is minimal movement in the length of a piece of timber.  In its width the expansion gap becomes more critical. Using OSMO allows the boards to move easily and freely without the unsightly gapping with bridging cracked flakes of finish. It is a superb choice.