Hardwood Floor Gaps & Cracks - Yikes!

During winter months complaints usually start trickling in. Often it's a new floor owner concerned with gapping. "They weren't there in the summer." Solid 3/4" hardwoods will expand and contract

Gapping occurs when hardwood floors lose their moisture content. Several factors can lead to it's cause. By examining it from a layman's view; even though the hardwood is no longer living and growing, it still contains cells that take on and lose moisture with changes in relative humidity.

Often gapping is a result of hardwood flooring that was installed during periods of higher humidity. Months may pass, even years, depending on the conditions until gapping becomes evident. A few unusually warm winters without the extensive use of heating in the home may not show the potential. Conversely, extreme cold winter months will require more heating. Dry air is forced into the environment. Moisture is now removed from not only the environment but the cells or pores of the hardwood. Contraction occurs.

How much gapping is dependent on several factors. Wider width boards will show more while narrow strip floors can show less. Methods to reduce gapping include the use of furnace humidifiers. These products work principally by evaporation of water that is introduced into the environment through the heating system. With more moisture in the air, cells in hardwood begin to expand.

Best Time To Install Floors?

Often a myriad of opinions can be found on this subject, but professionals agree finding what the average humidity level in the home year round will reduce contraction and minimizing gapping. It's also vital the actual installation and acclimation period be close to this level to achieve the best results. Products that test humidity, called hygrometers are best used to monitor jobsite conditions.

What Filler Will Fix My Gapped Floors?

Unfortunately no filler will work effectively unless the humidity level is kept constant. During the expansion process when warmer days allow for houses to be open to outside air, gapping will close up as the hardwood takes on moisture and the filler eventually gets squeezed out.

For very wide more permanent gapping, gluing rope with a urethane adhesive between boards has been successful. Caution should be exercised here as glues can stain and become rather noticeable once the floor is finished. Wiping clean with a rag and mineral spirits is suggested prior to the application of any finish.