This technical letter provides guidance on setting beds for tile to be placed over surfaces waterproofed with BITUTHENE® or PROCOR®.
There are two basic classes of tile setting beds:
- Portland cement mortar
- Thin set mortar
There are several materials used as thin set mortars such as latex-modified Portland cement and furan. As the name implies, thin set mortars are usually applied less than 1/4 in. (6 mm) in thickness.
There have been instances of poor adhesion of thin sets over some waterproofing systems. We do not recommend using BITUTHENE® or PROCOR® Membranes in conjunction with thin set mortar. BITUTHENE® and PROCOR® Membranes may be used in conjunction with wire mesh reinforced Portland cement mortar setting beds at a minimum thickness of 1 1/4 in. (31.75 mm) as recommended by the Ceramic Tile Institute. A protection layer between the BITUTHENE® or PROCOR® Membrane and mortar is required. Examples include HYDODUCT® 660, 1/8 in. (3 mm) asphaltic hardboard and 1 in. (25 mm) extruded polystyrene.
Please review the standard application procedures found on BITUTHENE® and PROCOR® Membrane Data Sheets.
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This document is only current as of the last updated date stated below and is valid only for use in the United States. It is important that you always refer to the currently available information at the URL below to provide the most current product information at the time of use. Additional literature such as Contractor Manuals, Technical Bulletins, Detail Drawings and detailing recommendations and other relevant documents are also available on www.gcpat.com. Information found on other websites must not be relied upon, as they may not be up-to-date or applicable to the conditions in your location and we do not accept any responsibility for their content. If there are any conflicts or if you need more information, please contact GCP Customer Service.
Last Updated: 2023-02-14