Topperfo products are manufactured from MDF (medium density fiberboard). These boards contain 8 - 10 % humidity content during manufacturing. The products are precision manufactured in our factory with computer controlled machinery. Because of the grooving and perforation, the surface area can double or triple, depending on the type of Topperfo product. Because of differences in humidity at the warehouse and the job site and variable humidity conditions in the warehouse or job site, the dimensions can change quickly before installation. According to the specifications of the MDF producers, the expansion and contraction of the MDF substrate can be as much as 4 mm per meter (0.048" per foot) in extreme conditions. It is mandatory to check the air humidity during storage and installation. Woodworking industry standards specify the following ranges in humidity and temperature:

air humidity		minimum 35 %	maximum 60 %
temperature		minimum 18°	maximum 30%

If these standards are adhered to by the installer of the Topperfo products, the maximum dimensional change of the MDF substrate amounts to 1 mm per meter (0.012" per foot). If the Topperfo products are mounted in the winter time, for example, with dry climatic conditions, an expansion joint must be provided corresponding to the dimension of the Topperfo product. If the products are mounted in spaces with high air humidity, the application of special humidity resistant cores is absolutely required. Different climatic conditions in the room and the hollow space between the suspended Topperfo planks or panels and the mounting substrate, can result in a convex or concave warping of the product. This circumstance must be considered by the installer, and addressed by using suitable fastening or reinforcement of the product. Topperfo products must be acclimatized for 3-4 days in the installation area before installation.

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Important Information- Expansion/Contraction Issues