Prenda sua primeira camada de compensado de compensado como você normalmente deveria.
A segunda camada (superior) de juntas de madeira compensada não deve coincidir com as vigas e a segunda camada não deve ser presa às vigas.
Citação do artigo de - Posição do underlayment para impedir que a telha e o Grout rachados Por Frank Woeste e Peter A. Nielsen Para publicação na Revista TILE LETTER ( leia o artigo completo ):
The 2003-2004 Tile Council of America’s (TCA) Handbook for Ceramic Tile Installation contains numerous details for a double layer wood floor system supporting ceramic tile. The thicknesses of the subfloor and underlayment are given in each case. Specific guidance on where to butt the underlayment end joints is not given for any detail. For example, for F142-03, the TCA Handbook states, “offset end and edge joints of the underlayment panels by at least two inches from the joints of subfloor panels; they should not coincide with framing below." It further states, “underlayment fasteners should not penetrate joists below." In the case of F150-03, the offsetting is not mentioned, but it does state, “underlayment fasteners should not penetrate joists below." The same holds true for F155; however, it also states, “face grain of plywood should run perpendicular to trusses, I-joists, or sawn lumber for maximum stiffness." The purpose of this article is to propose specific guidelines for the orientation and placement of underlayment, including end and edge joints, beyond the rules given in the TCA Handbook, to improve the performance of double layer wood systems. These guidelines are based on engineering science and field observations.
Além disso, como você usará o Ditra, siga as diretrizes deles para fins de garantia. Especificamente, consulte as páginas 8 e 23 do The Ditra Handbook para sua inscrição.