Main image upload

May 2015


I have been renting an apartment for the past five years. I have enjoyed living in this apartment since I moved in and there have been very few maintenance issues during this time period. The apartment has not suffered from damp or moisture.

However, very recently, I have noticed that a section of the wooden floor has started to rise up at the seam between the boards, creating an uneven surface. Could you explain to me why this is happening as it is becoming more noticeable and I would be grateful if you could provide some solutions.





You have not said whether the apartment is at ground or upper level which may well have a bearing on the problem. There are a number of things to consider – leaking plumbing pipes from heating, water supply and wastes pipes as well as dampness from an external source such as raised ground levels or drainage problems. I note that it is a recent problem and that you have had no evidence of any previous issues with dampness, but it is important to check all potential sources.

I assume the wooden floor is natural timber as opposed to factory made laminate flooring.

Your description of the board distortion at the seam appears to be what’s known as “cupping”. Cupping is described as boards with their edges either higher or lower than the centre of the board. It is a common complaint that develops with high humidity.

Heat in a specific location or a very dry environment above the floor may result in cupping. Timber is a natural product that will shrink and swell in response to changes in atmospheric humidity. A small amount of cupping can even occur in some locations within a dwelling, for example where the floor is exposed to the sun.

During warm, humid weather, wood expands, during dry weather it contracts. In winter, when homes are heated and the air is dry, wood flooring gives up some of its moisture and therefore shrinks. This seasonal movement is a normal characteristic of wood flooring, sometimes it’s noticeable but it never stops, regardless of the age of the wood.

Most forms of timber distortion are driven by changes in moisture content of the timber. In high humidity rapid drying can cause distortion of timber as one side dries quicker than the other, or one side has a lower moisture content than the other. Assuming it is a humidity problem, then try and regulate the room temperature and avoid high levels of heating, air conditioning, etc. The timber should settle back to its original form, otherwise I would seek advice.

James Drew is a member of the MediKids.