Gaps occurring in wooden floors are common and can happen when there are changes in the moisture content within the wooden flooring. Whilst some gaps in the flooring are unavoidable, extreme gaps can become a cleaning nuisance and even a tripping danger. However, not all gaps should be filled.
Gaps can occur for one of two reasons. First, gapping can occur as a result of a change of season or changes of humidity. These changes in humidity can cause wooden flooring to swell or shrink as the moisture content in the air, and thus in the wood, changes. For this type of gapping, as the seasons change again, the gaps will decrease in size and will usually close completely. If this is the case for the gaps in your wooden flooring then it is best not to fill the gaps because this will lead to problems when the wood expands again, and in some cases can cause the wood to buckle.
The second kind of gapping can occur with older wooden flooring, particularly with wide planked flooring, where gaps are inevitable. This type of gapping is the result of the wood drying up and shrinking over time. This problem can also be exacerbated if the boards were laid during the humid season, when the wood has been water damaged or when the floorboards are close to a furnace. This type of gapping is more permanent than the previous type, but they may still get smaller during the dry season. Before having them filled or repaired, it is best to assess whether the gaps are present all year round. If the gaps are wide enough for a coin (standing up) to fit between the floorboards during the most humid time of year, then it is best to have the gaps fixed
