Often, in a world surrounded by concrete and man-made products, we don't often stop to think about what is natural. Wood, being a natural product responds to humidity variations, expanding and contracting even when the wood is dried and placed in a floor. While often harder to schedule because of activity usage, winter is actually the more ideal time to recoat a wood floor. Dry, cold winter weather makes the wood contract, which sometimes causes gaps between planks, but this is more ideal than in summer when the humidity makes the wood absorb moisture from the air and expand as a result.
So what creates less than ideal drying conditions for your wood floor?
- Temperature: The ideal temperature for application can vary depending on product, but the average temperature that is the most perfect for applying floor finishes is 75 degrees. The temperature of your gymnasium affects the viscosity of the floor finish, aka. how thick of a film the finish creates. Thinner is always better so you can see why summer refinishing projects can pose challenges when temperatures get up over 80 degrees in a building without air-conditioning.
- Humidity: In the most ideal of settings, a buildings humidity levels would be around 50% for refinishing, however can still be applied properly up to 75%. Humidity affects the evaporation rate of the solvents and the length of time required to properly cure the floor.
- Air Flow: Good air flow is critical. After the solvent evaporates, the film is very weak. It must be strengthened by cross linking with oxygen. A good air flow determines how much oxygen will cross link with the finish to initiate the curing process. AIR CANNOT BE STAGNANT! This ties back into the humidity in the air as well. In higher humidity situations, we can still achieve a positive outcome if the air flow is good. By cycling fresh air through the room, the drying process will not be hindered as much in high humidity situations. Another critical point worth mentioning is that we never want air blowing directly on a newly finished floor. This creates a scab on the surface of the floor and prevents the floor from drying from the bottom up.
To cure a floor completely can take several days, but 24 hours is usually enough for the top coating. Floors will be 90% cured in 7 days and fully cured in 30.