• Before installing wooden flooring, control that the room is in correct condition, that the windows are closed, and that all paintwork is dry. Air temperature must not be less than 18°C (ideal temperature 18/22°C), and the relative humidity level must be between 45% and 60%. We recommend these temperatures and humidity levels be maintained permanently after the floor has been laid to guarantee that the flooring remains in perfect condition over time.
  
  
• Control that the cement screed sub-floor is as level as possible (the maximum acceptable tolerance is 5 mm over a 2-metre span, measured using a rigid rule). The moisture content of the cement screed must not exceed 2% in weight. When installing flooring over other types of sub-floor (old wooden floors, ceramic tiles, etc) please contact our company for further advice.
  
  
• When installing flooring over underfloor heating, control that this type of wooden flooring is suitable for underfloor heating systems (see product data sheet). Also check that the minimum cement screed curing and maturing time has been respected and control that the cement screed heating has been performed correctly. Gradual start-up of the heating system is used to stabilise the cement screed as it will eliminate any possible tension and will bring it to the required dryness level according to the climatic conditions in the room where the flooring is to be laid; this will prevent releasing moisture into the wooden flooring. Before floor installing it is important to control that a vapour barrier is created between the levelling and insulation layers. Check that the minimum thickness of the cement screed is 6 cm, and that the thickness over the heating pipes is at least 3 cm. The minimum curing/maturing times for various types of cement screed must be respected before starting up the heating system:
  – 21 days for cement screeds
  – 7 days for anhydrite screeds
  – 3-4 days for rapid-drying screeds (always follow the manufacturer’s instructions).
  
  

• Once the heating system has been switched on, increase the fluid temperature by about 10°C each day until a temperature of 50°C has been reached; maintain the maximum circulating fluid temperature for at least 10 consecutive days and ventilate the rooms adequately. After this period, gradually cool the fluid temperature by 10°C per day down to 20°C. Switch off the heating 5 days prior to floor installing. In any case, before starting to lay floor boards, control that the surface temperature of the screed is approximately 15/20°C and that the relative humidity level in the room is 45/60%. To avoid possible wooden flooring shrinkage caused by drying out, it is advisable to maintain the underfloor heated slab below a temperature of 26-27°C and the relative air humidity levels between 45% and 60%. This is to ensure an adequate balance in wood moisture content (relative information and data sheets are available on our web site).

• Carefully control that the selected flooring type is suitable for the environment before beginning any installing operations (moisture level, processing, and finish).
  
  

G&G Flooring will not accept any claims concerning products after floor laying has been started.