Wood is a LIVING material, i.e., it is hygroscopic and thus tends to absorb or lose water, depending on the environmental conditions in which it lives.  In other words, depending on the relative humidity and air temperature, so that each environmental state accounts for one degree of humidity in wood.  This is known as the hygroscopic balance.

Therefore, it is important to consider that the humidity content fluctuates, depending on each situation and the annual change in the environmental conditions in which it lives until it reaches the correct balance with those conditions.

Source: MANUAL FOR INSTALLING WOODEN PAVING. AITIM. 1997

Storage of the Parquet flooring on the site: The parquet flooring must be stored on the site under cover, in a cool, well-ventilated, clean, dry place. To ensure the proper maintenance of the Parquet, it must be stacked, leaving free spaces between the wood, the floor and the walls. If the parquet is wrapped in shrink wrap, it must be kept in the wrapping until use. If the packages are grouped in pallets, they must remain on them until use. Packages of solid wood flooring and floating Parquet must be stacked on rails, with a separation between each other of at least 50 mm for perfect maintenance.

Relative Humidity: According to the UNE 56-810 standard recommendations, the Parquet or sold wood flooring must not be installed until the hygrometric level of the location is below 70%, in coastal areas (with a humidity content in wood of between 9 and 11%), and 50% for interior regions (with a humidity content in wood of 7 to 9%). The humidity of the walls must be less than 2.5%, except in the case of plaster and paint, which should not exceed 5%.

Humidity content and setting: The humidity content of the floor must be less than 2.5%. Humidity values of up to 3% are admitted, using wood with a humidity content that is slightly higher (between 10 and 12%). The 3% value must not be exceeded in any case. It is assumed that a humidity of 4 to 5 degrees will be transmitted to the paving for every degree of humidity in the floor that exceeds 4%.

Cohesion and hardness of Parquet and solid wood flooring: The surface must be hard and rigid enough to withstanding the nailing or screwing of the rails in the case of solid wood floors, or the traction stress of adhesives in the case of Parquet flooring.

Flatness and horizontalness: The surface on which the Parquet or solid wood flooring is to be laid must be flat and horizontal.

Cleaning: The surface must be clean and free from elements that could make it difficult to perform the gluing operations, lay the rails or ensure the proper seating of the boards on the floating structures.

Glazing and closing of window openings: All window openings in the building must be properly closed and glazed to prevent the effects of frost, rainwater, excess environmental damp, direct sunlight, etc.

In the finishing operations, it is important to ensure closing, to prevent draughts or dust from entering and causing the varnish to set too quickly, which could damage the solid wood or parquet flooring.

Other recommendations: The laying of terrazzo, stone or marble tiles in bathrooms, kitchens and landings must be completed before installing the Parquet. All work involved in applying whitewash and plastering must be completed first.  Door sub-frames must be put in place first.

Provisional protection of the work until delivery: The varnishes that are normally used in wooden paving reach their maximum resistance approximately 15 days after being applied (but they dry only a few hours after application). If possible, respect this term, as it will have a positive effect on the durability and appearance of the varnish and in short, on the care and maintenance of the Parquet flooring  in the future.

If it should be necessary to execute additional work and tread on the freshly-varnished flooring, it must be protected with corrugated cardboard or other permeable materials.

WHEN YOU FIRST ENTER YOUR NEW HOME:  It might be considered that the critical period for wooden or Parquet flooring  is the first year of life. You should bear in mind that the environmental humidity of the home will be subject to important alterations once it is inhabited (damp, cleaning, heating, etc.).

1.     Previous recommendations for maintenance or care: Avoid sudden changes in temperature and humidity. Keep your home at a temperature of between 20º and 22º if possible, with a relative humidity level of between 55% and 65%.

Make sure the humidity levels of your home are maintained and if necessary, place small containers filled with water near the radiators. When you first turn on the heating every year, do it at a low temperature and gradually increase it every day, until the required temperature is reached (20-22º C).

Try to prevent the sunlight from constantly shining on the wooden floor or parquet. The visible effects that this produces, in the event of not being able to avoid it, are the cracking of the boards, caused by excess drying of the wood.

The more changes in humidity there are, the more the Parquet flooring will suffer from cracks, warps and other defects,... due to lack of  humidity;  and in the case of excess humidity, damage to the surface of the boards, white varnish, blackened zones, etc.

Recommendations for preventing the parquet flooring from becoming damaged:  Place a doormat at the entrance to prevent grit, water, dirt, etc. on footwear from entering, and damaging the floor.

If you are away from home for a long period of time, leave window open to create a small draught and containers with water in each room.  Lower the blinds.