By Gregory Mowat, Forensic Tile Consultants
Understanding the differences and similarities between crack isolation membranes and waterproof membranes (suitable for direct bond of ceramic, glass, and stone tiles) is imperative to the success of your installation.
The tile industry is continually evolving with products that make installation assemblies thinner, while addressing deficiencies and/or future deficiencies in the substrate to which the assembly is bonded. Industry standards have purposely been created in order to have successful installations and to reduce failures.
American National Standard Specifications for the Installation of Ceramic Tile (ANSI) Material and Installation Standards | ANSI A108, A118, and A138
ANSI A118.12 American National Standard Specifications for Crack Isolation Membranes for Thin-Set Ceramic Tile and Dimension Stone Installation
Originally adopted in 2005 and reaffirmed in 2010. Purpose of the crack isolation membrane is to isolate the tile or stone tile assembly from minor in-plane substrate cracking. The standard applies to liquid membranes, sheet membranes and trowel applied membranes. Crack isolation membranes provide the lowest profile (elevation or thickness) of the tile or stone tile installation incorporating a crack isolation membrane. A118.12 was developed to provide a standard with the minimum criteria necessary for a material to function as a deterrent to crack propagation from the substrate through the finished thin-set tile or stone tile installation.
ANSI A108.17 Installation of Crack isolation Membranes for Thin-Set Ceramic Tile and Dimension Stone
Originally adopted in 2005 and reaffirmed in 2010. The standard is a guideline for installing crack isolation membranes that comply with ANSI A118.12. Crack isolation membranes are used over existing substrate cracks, or over substrate areas susceptible to future cracking.
Installation of proper movement joint placement is required and manufacturer’s instructions may specify additional movement joints to prevent crack transmission transferring through the finished tile or finished stone tile installation. Consult manufacturer’s instruction for cure time, thickness, specific instructions, application, performance levels, and limitations including acceptable limits of moisture and alkalinity concerning the crack isolation membrane. Follow the crack isolation membrane’s written instructions precisely.
ANSI A118.10 American National Standard Specifications for Load Bearing, Bonded, Waterproof Membranes for Thin-Set Ceramic Tile and Dimension Stone Installation
Originally adopted in 1993 and renewed on a five-year cycle by the ANSI Committee. It was adopted by the International Conference of Building Officials (ICBO) in 1994 and reaffirmed by the International Building Code in 2006. AC115 requires where tile or dimension stone tile is directly bonded to a waterproof membrane, the waterproof membrane must meet ANSI A118.10 requirements.
Assembly method F122 was first published in the TCA Handbook for Ceramic Tile Installation in 1994.
The purpose of the waterproof membrane for thin-set ceramic tiles and dimension stone installations functions as a barrier to positive liquid water migration. The standard applies to liquid membranes, sheet membranes and trowel-applied membranes. Waterproof membranes provide the lowest profile (elevation or thickness) of the tile or stone tile installation while incorporating a waterproof membrane. The standard also describes the test methods and minimum requirements for load-bearing, bonded, waterproof membranes for thin-set ceramic tile and dimension stone installation.
ANSI A108.13 Installation of Load Bearing, Bonded, Waterproof Membranes for Thin-Set Ceramic Tile and Dimension Stone
Originally adopted in 2005 and reaffirmed in 2010, the standard is a guideline for installing waterproof membranes that comply with ANSI A118.10. Installation of proper movement joint placement is required. Consult the manufacturer’s instruction for cure time, thickness, specific instructions, application, performance levels, recommended testing and limitations concerning the waterproof membrane. Follow the waterproof membrane’s written instructions precisely.
In order to install an ANSI A108.13 load-bearing, bonded, waterproof membrane in a tile-lined shower receptor or a curbless shower receptor, the waterproof membrane must be product certified (approved) by International Association of Plumbing and Mechanical Officials (IAPMO). Installation materials must be specified or approved by the waterproof membrane manufacturer for proper bonding to the specific waterproof membrane.
The Tile Council of North America (TCNA) publishes American National Standard Specifications for the Installation of Ceramic Tile (ANSI) annually, including the material and installation standards. Copies are available from the TCNA, tile trade associations, manufacturers and distributors.
Installation Methods Published Yearly in the TCNA Handbook for Ceramic, Glass and Stone Tile Installation
The TCNA annually also publishes the Handbook for Ceramic, Glass and Stone Tile Installation. The following installation methods are from the above-mentioned handbook. They include assemblies with crack isolation membranes, options for crack isolation membranes, and waterproof membranes.
Assembly methods which include crack isolation membranes as part of the assembly include:
- F200, F200A, F205, F205A, F125-Partial, F125-Full, F128, RH110, RH110A, F147, F148, F200 Stone, F200A Stone, F205 Stone, F205A Stone, F125-Partial Stone, F125-Full Stone, F128, RH110, RH110A, RH111 Stone, RH111A Stone, and RH112A Stone.
Assembly methods which include crack isolation membrane as an option include:
- F102, F104, F113, F200, F200A, F205A, F128, RH110, RH110A, RH117, RH111, RH111A, RH112, RH112A, RH116, RH116A, RH122, RH123, RH141, RH140, F141, F152, F180, F185, F102 Stone, F113 Stone, F113A Stone, RH110A Stone, RH117 Stone, RH111 Stone, RH111A Stone, RH112 Stone, RH112A Stone, RH116 Stone, RH116A Stone, and RH141 Stone.
Note that the manufacturer may have limitations on the width of a crack the crack isolation membrane will prevent from transferring up through the tile or stone tile assembly.
Assembly methods which include waterproof membranes as part of the assembly include:
- F200, F200A, F205, F205A, F121, F122, F122A, F200 Stone, F200A Stone, F205 Stone, F205A Stone, F121 Stone, F122 Stone, F122A Stone, RH111 Stone, RH111A Stone, RH112A Stone, B421 Stone, and B422 stone.
Assembly methods which include waterproof membranes as an option include:
F101, F102, F103, F103B, F104, F112, F113, F113A, F115, F115A, RH117, RH111, RH111A, RH112, RH112A, RH116, RH116A, RH122, RH123, RH141, RH140, F141, F145, F150, F160, F144, F146, F170, F149, F151, F152, F155, F180, F185, W201, W202E, W244E, W211E, W202I, W221, W22, W231/W241, W244C, W244F, W245, W247, B411, B440, B412, B419, B430, B414, B441, B415, B420, B421, B422, B421C, B422C, TR420, C511, C512, C513, SR613, SR614, P602, P617, S151, F101 Stone, F102 Stone, F103 Stone, F103B Stone, F104 Stone, F112 Stone, F113 Stone, RH117 Stone, RH111 Stone, RH111A Stone, RH112 Stone, RH112A Stone, RH116 Stone, RH116A Stone, RH141 Stone, F141 Stone, F250 Stone, W201 Stone, W202E Stone, W244E Stone, W211 Stone, W202i Stone, W221 Stone, W222 Stone, W231/241 Stone, W244C Stone, W244F Stone, W245, Stone, W247 Stone, B411 Stone, B440 Stone, B412 Stone, B419 Stone, B430 Stone, B414 Stone, B441, Stone, B415 Stone, B420 Stone, B426 Stone, and B431 Stone.
Tips for Success
Terminology used by manufacturers may be confusing. While checking online with several manufacturers, the names used for crack isolation membranes were inconsistent to the terminology in ANSI A108.17. Anti-fracture, crack isolation, crack prevention, crack suppression, reflective cracking, and uncoupling are some of the terms used.
Further, bonded waterproof, drainage, low perm, moisture control, vapor retarder, waterproof, waterproof coating, waterproofing, water resistant, and weatherproofing are the various terms used by the manufacturers for ANSI A118.10.
Slip sheet used as a cleavage membrane is used to isolate a wire-reinforced mortar bed from bonding to a concrete slab. Installation of reinforced asphalt paper duplex paper, asphalt laminated paper, scribing felt, and roofing felt along with crack isolation membranes and waterproof membranes may be used to isolate a wire-reinforced mortar bed from bonding to the underlying concrete slab or wood floor.
However, installation of reinforced asphalt paper duplex paper, asphalt laminated paper, cork, scribing felt, upside down vinyl, vinyl and roofing felt are subject to failure where installed directly to a concrete slab with mastic with direct bond of the tile or stone tile to the slip sheet. The mastic may re-emulsify with moisture/vapor migration from the concrete slab and lose bond from the slip sheet to the concrete slab. Additional items to keep in mind include:
For radon protection through concrete slabs, check with the membrane manufacturer.
- For sound control and bonded sound reduction membrane installation on floors above grade with separation of different occupancy, check with the manufacturer for meeting ANSI A118.13 requirements.
- The Marble Institute of America (MIA) recommends a waterproof membrane to separate stone tiles from direct bond to concrete slabs on grade, interior and exterior.
- Stone tile installations on post-tensioned concrete assembly method F111 Stone is the only method of installing stone tile over post-tensioned slabs, on-ground or above ground. Dynamic movements of post-tensioned slabs have proven problematic for directly adhered stone tile.
Also, where an ANSI A118.10 is installed for a shower receptor or curbless shower receptor, the membrane must be IAPMO approved. Where a curbless shower is installed, the bathroom floor assembly is required to be waterproofed.
Further, where a waterproof membrane is installed by others and as the installer, you are directed to directly bond the tile or stone tile directly to the waterproof membrane, verify the waterproof membrane meets ANSI A118.10 requirements, or issue a waiver in writing of non-responsibility for future failure.
The third option is to decline to perform the installation with direct bond of tile or stone tile to an unrecognized waterproof membrane. One of the reasons the tile industry has standards and methods of installation is to reduce future failures of the assemblies in the field. Roofing waterproof membranes not meeting ANSI A118.10 requirements are almost guaranteed to lose bond with application of tile or stone tile directly to the roofing waterproof membrane. Be cautious if the roof membrane has aggregate (sand) to accommodate the direct bond of tile to the waterproof membrane.
It should be noted that medium bed mortars were suitable for up to 3/4“-thick installation for direct bond of tile to crack isolation and waterproof membranes. The term medium bed mortar has changed to large format mortar for large and heavy tile, and is suitable for up to 1/2“-thick installation for direct bond of tile or stone tile without wire reinforcing.
Large and heavy tile mortars are not suitable for leveling a floor. Caution is urged with large and heavy tile with direct bond over a peel-and-stick membrane as the membrane manufacturer may not warrant the membrane where mortar thicker than 3/8” is used to install tile or stone tile directly to the membrane.
Moreover, using an uncoupling membrane (a plastic membrane geometrically configured to provide air space between the tile or stone tile) and the substrate allows independent movement between the substrate and the tile or stone tile, and limits the transfer of stresses. As there is no current ANSI or ISO Standards, consult the manufacturer of manufacturer’s written literature for specific application details.
Installation of crack isolation membranes meeting ANSI A118.12 following A108.17 and installation of waterproof membranes meeting ANSI A118.10 following A108.13 reduce future failures with direct bond of tile and stone tile.
Lastly, remember to verify if movement/expansion joints are necessary and coordinate the installation of proper materials meeting EJ171.