Installing Large Format Thin Porcelain Slabs

Have you seen the wave of new “thin porcelain bodied panels” that have hit the market? These product types range in thickness from ~1/8” (3.5mm) to 5/16” (7mm) and some may be manufactured with a resin or mesh backing. Undoubtedly, the resin or mesh backing provides stability to the thin porcelain panels. Many of the manufacturers of these slim porcelain panel products are suggesting that their products can be used for interior vertical applications and limited interior floor applications. Consult with the thin porcelain panel manufacturer for their recommendation on which specific panel type and thickness is suitable for a specific application. Note that not all thicknesses in a manufacturer’s product range are suitable for all applications. Exterior applications and demanding floor applications may require the use of a specific manufacturer’s porcelain panel (type and thickness) that has been rated for the application and area of use.

LATICRETE International, Inc., the world leader in ceramic tile and stone installation systems, has had a long and successful history of installing thin, ceramic tile panels dating back to the early 1970’s. Based on our successful track record, the following installation systems can be specified for today’s innovative, thin porcelain panel installation challenges. Special installation techniques are required for successfully installing thin-body porcelain panels. For example, using a glass installer’s “vacuum suction cups” and / or “installation frames” can facilitate easier handling and placing of the panels and reduce the chance of cracking them during handling and installation. Consult the thin porcelain panel manufacturer before selection and installation to determine the porcelain panel’s suitability for the intended area of use and the specified project. It is highly recommended that the manufacturer of the thin porcelain tile provide information regarding the tile’s suitability and acceptability for the intended use of the tile and for the service rating of the tile.

SUBSTRATE PREPARATION:

The main challenge for installers is to make sure that the substrate is extremely flat, so as to achieve the required coverage. Floor installations of thin-body porcelain panels are only recommended over interior concrete floor slabs (and approved existing interior ceramic tile over concrete) that meet the maximum allowable deflection standard of L/360 under total anticipated load. Installations over wood-framed floor constructs are not suitable for most of these panels. Floor substrates for the installation of thin-body porcelain veneer panels must be prepared to a Floor Flatness (FF) of 50. The floor flatness (FF) requirements should be determined just prior to the installation of the thin porcelain tile/panels. If the slab does not meet the floor flatness requirements then appropriate surface preparation should be conducted. Maximum variation in the substrate is not to exceed 1/8” in 10’ (3mm in 3m) from the required plane, and no more than 1/16” in 12” (1.5mm in 30cm) when measured from high points. Please refer to LATICRETE TDS 233 “Floor Flatness (FF) and Floor Levelness (FL)” for more information. Typical interior wall substrates are concrete, concrete block and cement backer board. Typically, the following LATICRETE Polymer Fortified Mortars and LATICRETE® or DRYTEK® Self-Leveling Underlayments can be used to properly prepare a substrate prior to the installation of these thin porcelain panels:

• LATICRETE 3701 Fortified Mortar Bed
• LATICRETE NXT™ LEVEL PLUS
• LATICRETE NXT LEVEL
• DRYTEK 4000
• DRYTEK 7200
• DRYTEK 7400
• DRYTEK 7600

INTERIOR - walls and limited floor applications based on porcelain panel manufacturer’s recommendations:
Porcelain panel manufacturer installation information and product testing that has been received / conducted to date reveals that the following LATICRETE / LATAPOXY products can be used for interior applications:

• LATICRETE 254 Platinum
• LATICRETE 254R Platinum Rapid
• LATAPOXY® 300 Adhesive
• LATAPOXY 210 Adhesive

EXTERIOR FACADES

(based on porcelain panel manufacturer’s recommendations):
In some cases, requests have been made to use thin profile porcelain panels on exterior applications. Please note that for exterior veneer installations, the thickness of the panels can be a concern. The 2012 International Building Code (IBC) - Chapter 14 – Exterior Walls - requires that “adhered veneer finish types” (which include ceramic and porcelain tiles) be a minimum of ¼” (6mm) thickness for use as exterior cladding. In addition, facial size dimensions can also be a factor. For porcelain tile, the 2012 IBC [Section 1405.10.2] requires that exterior adhered porcelain tile be a maximum of 24” (610mm) in any face dimension nor more than 3 square feet (0.28m2) in total face area and shall not weigh more than 9 lbs. per s.f. (44.2 kg/m2).

Therefore, the project Architect or Engineer will have to gain code approval for the use of a thinner and larger format porcelain panel finish material for use in these applications. The following LATICRETE® products can be used for these applications upon code approval:

• LATICRETE 254 Platinum
• LATICRETE 254R Platinum Rapid

In addition, exterior façade installations should be waterproofed to help prevent the infiltration of water into the structure and to protect building elements from corrosion. HYDRO BAN® or LATICRETE 9235 Waterproofing Membrane are ideal waterproofing membranes for exterior façade installations and are 100% compatible with LATICRETE adhesives and mortars used for these installations.

NOTES:
Obtaining complete mortar coverage between the porcelain panel and the substrate (100%) is absolutely essential to the long term performance of the porcelain panels. Using the appropriate specialty notched trowel (e.g. European Tile Masters Euro Notch Trowel or Raimondi Flow Ridge Slant Notch Trowel) along with proper troweling techniques and backbuttering will make achieving complete coverage easier. To help ensure maximum coverage to both the substrate and to the back of the porcelain panels, mix the adhesive to a slightly wetter consistency than as a typical thin bed mortar (Mortar ridges must still hold their shape).

Apply notched coats of the thin-set mortar to BOTH the back of the panel and the substrate. Typically, the trowel ridges are applied in straight lines and should be parallel to each other when placed (unless otherwise directed by porcelain panel manufacturer). Do not allow the mortar to dry or skin over during the installation process. Care must also be taken when removing a panel to inspect the thin set mortar coverage during the installation process and while the mortar is still wet to avoid damaging the thin porcelain panels during this process. The use of hand held “vibrating” pads can assist in properly bedding the panels and achieving maximum adhesive mortar coverage.

Allow a minimum of 72 hours for cure time at 70°F (21°C) prior to exposing floor installations of thin-body porcelain panels to light foot traffic only. Regardless of whether rapid or normal setting thin set / medium bed mortars are used, LATICRETE typically requires that floors need to be protected from heavy traffic, lifts, etc.... for at least 7 days at 70°F. Full cure typically occurs in 28 days at 70°F. However, cooler temperatures (and other climatic conditions) and the size of the porcelain panels can impact the cure rates. In addition, anytime heavy lifts or other equipment is exposed to the floor, protection of the tile should be put into place (typically 3/4" thick plywood / OSB). See the Tile Council of North America’s (TCNA) statement of protection on this matter in the current TCNA Handbook for Ceramic, Glass and Stone Installations. It is important to note that the above cure rates are typical, but can be affected by many variables. Consult with the thin porcelain panel manufacturer for their suggestions on cure rates, time to traffic and protection of newly installed projects.

Using mechanical edge-leveling systems for floor applications (e.g. Tuscan Leveling System) can help reduce lippage and achieve complete coverage beneath the porcelain panels; especially at the edges and corners.

Bonding issues of the resin or mesh backing to the thin-body porcelain panels (or any tile or stone) is outside of the control of LATICRETE and is an issue of which the tile manufacturer is responsible.

GROUTING

Since the panels are so thin, extra attention must be given to “clean out” any adhesive mortar left in the joints during the installation in order to facilitate grouting, and the acceptance of enough grout within the grout joint. In most cases, half the depth of the grout joint should be available to receive the grout. For 1/8” (3mm) thick porcelain tile that would be only 1/16” (1.5mm). This may not be enough to allow the grout to remain in place. Therefore, the entire depth of the panel should be free of adhesive in the joints to receive the grout.

Interior Applications:
• SPECTRALOCK® PRO Premium Grout
• SPECTRALOCK PRO Grout
• PERMACOLOR® Grout
• LATICRETE® 1776 Grout Enhancer mixed with LATICRETE 1500 Sanded Grout or LATICRETE 1600 Unsanded Grout

Exterior Applications:
• PERMACOLOR Grout
• LATICRETE 1776 Grout Enhancer mixed with LATICRETE 1500 Sanded Grout or LATICRETE 1600 Unsanded Grout

MOVEMENT JOINTS

Joints scheduled to act as movement joints should also be cleaned out of all adhesive mortar and grout in order to receive bond breaker tape and the suitable sealant so as to allow the movement joint to function correctly. Use LATICRETE LATASIL™ to treat the movement joints. Follow standard industry guidelines for movement joints in accord with Tile Council of North America’s movement joint details and information EJ-171. For more information on the nuances of installing large format tiles and stones, see LATICRETE TDS 193 “Installation of Large Format Tile & Stone”.

Technical Data Sheets are subject to change without notice. For latest revision, check our website at www.laticrete.com

Source: http://www.laticrete.com/portals/0/tds/tds170.pdf