SCHLUTER SYSTEMS LP

Did you know that natural stone installations over wood sub-floors require a mandatory second layer of subfloor before a backer-board or DITRA can be installed? The detail from the Schluter Systems DITRA installation handbook (D-W-S and DPS-W-S page 6) shows this requirement for this application. We emphasize this detail as often as opportunity allows, specifically during our Innovation Workshops. We make all handbook details and information readily available in both printed and digital formats. Schluter has adopted this second layer requirement from TCNA (Tile Council of North America), F141-25 and F250-25 details. The two accepted assemblies are either (1) a wire reinforced mortar bed over a slip sheet membrane (minimum 1 1/4” & max 2” reinforced mud bed), or (2) a second layer of OSB minimum 3/8” thick before (a) approved tile backer-board or (b) Schluter DITRA Uncoupling Membrane (as noted in our detail). It does not matter how firm you feel the floor is.  It does not...

SCHLUTER DITRA INSTALLATION HANDBOOK MOVEMENT JOINTS | Pages 15-17  DISCUSSION Movement joints are an integral part of any tile assembly. The various components of a tile assembly (tile, mortar, substrate, etc.) have unique physical characteristics that affect their behavior. Specifically, these components will expand and contract at different rates, according to each component’s intrinsic physical properties, with changes in moisture, temperature, and loading (both dead and live loads). This differential expansion/contraction of attached components results in internal stresses. Furthermore, structures that restrain overall expansion of the tile field (walls, columns, etc.) cause stress buildup within the system. If the aforementioned movements are not accommodated through the use of movement joints in the tile field and at restraining structures, the resulting stresses can cause cracking of the grout and tile and delamination of the tile from the substrate. Thus, movement joints a...